Hi everyone,
I've got the fairly common GTV6 won't start issue and have got to the point where I'm stuck and hoping someone has that spark of inspiration that will get this working. I should say I have read every thread I can find on these sort of problems and have followed much of the advice as described below.
Drove the car home a week or so ago. It was running great and I really enjoyed the drive. Parked it and went back next day for another drive. Car kicked a few times, seemed like it was about to catch but then died. No amount of turning it over since, at different times and with different throttle positions, has coaxed it in to any kicking whatsoever.
Have confirmed the fuel pump is working by the hold air flap open method. Can clearly hear pump going and can feel some vibration in some hoses. Interestingly, most vibration in return hose, hardly any in delivery hose. Removed delivery hose and with end pointed into large bottle, did it again. Sure enough, fuel came out continuosly, although not under as much pressure as I expected.
Turned to spark. Put 5 new plugs in just to be sure (have yet to make plug remover for 6th plug). Put timing light on and turned engine over. Timing light flashes as supposed to, so there must be some spark. Not sure how strong it is though, because I also tried taking plug leads off as engine was turning over and didn't feel the slightest kick.
Stuck voltmeter on various fuses and leads and all seemed fine with one possible exception. The green lead to the positive on the coil showed 12 volts when pulled off the coil and connected straight to the voltmeter, but only half that when actually connected to the coil. No idea what this proves other than maybe its a sign that the coil is kaput.
So, now I'm stuck. I know its getting fuel, but not convinced its getting enough. I also know its getting spark but also not convinced its enough. And maybe its something altogether different. I'm considering going and buying a coil, fuel pump and filter and replacing all of them, but would rather not waste the money if possible.
Can anyone suggest what to try next?
Cheers, Alby
Hi there
Spray some start you bastard through the intake, and see what happens, sometime that will give enough to kick it, also maybe you have a bad batch of fuel that have blocked the injectors, try the spray first and let us know what happens.
Thanks Dehne. Good idea. I will try this but not till late tomorrow as I haven't got any Start you Bastard here. Will let you know what happens. Cheers
Get a spark plug and connect it to a spark plug lead, and kick the engine over, and see if the spark plug has a spark, also the volts going to the coil is never the full 12 volts, if you have a resister coil, when the starter motor is kicking over and say has reduced the battery to 10 volts, then the coil will be giving a big fat spark to start the engine, when the engine is running the resister will cut down the volts to the coil to say 8 volts, if it ran 12 volts, you would burn the coil out, after you kick the engine over take out a spark plug and see if it is wet, if it is you don't have a spark to set fire to it, if the spark plug is dry, then you have no fuel to start the fire, Colin.
Hey thanks colcol. That's a very clear description of a few things that will help me narrow down the diagnosis. I never new that about coils- very interesting. So, tomorrow evening I'll try out your spark plug methods, followed by some Start you bastard if it still seems applicable, and hopefully end up with a better picture of what's going on. Will report back then. Cheers
How long since the fuel filter was changed? Clogged filter is a common cause of hard start on these cars.
No idea Alister
Hey Alby, there's plenty of suggestions on this hyper-link that may assist. Make sure you post your diagnosis and hopeful resolution.
http://www.alfagtv6.com/discus/messages/200/592.html?0 (http://www.alfagtv6.com/discus/messages/200/592.html?0)
No idea Alister. I only recently bought the car. If the other suggestions don't show anything I'll try changing the filter. The one on there at the moment is one of those you can't see into, so changing it is the only option. Sounds cheaper to try than a fuel pump so it'll be the next item on my list.
Lots of great suggestions. I love alfa forums - they are one of the reasons I felt comfortable buying a car I didn't know that much about. Great stuff & thank you all.
Yeah Alby - much cheaper than a pump! The filter is a regular service item but its often an out-of-sight, out-of-mind thing. Very easy to replace and if you do cut it open. You may be unpleasantly surprised at the c..p in there.
To test your coil: disconnect wires from all but one terminal and measure the resistance with your ohmmeter. I've attached the specs from the 1985 ALFA workshop manual, hopefully your coils is listed. if not then at least you should be in a similar range.
(//)
Also I had a sticky AFM flap once. Pump would run when flap held open by hand, but would stick shut when cranking and pump wouldn't go. Symptom was fire from CSI fuel then die. Took a while to notice that. Pulled the sucker out and gave it a thorough clean.
Good Luck,
Al.
Quote from: Albygtv on September 09, 2012, 09:57:37 PM
No idea Alister. I only recently bought the car. If the other suggestions don't show anything I'll try changing the filter. The one on there at the moment is one of those you can't see into, so changing it is the only option. Sounds cheaper to try than a fuel pump so it'll be the next item on my list.
Always a good idea to put on a fresh one, but you can check it in the meantime by whacking it on the ground a few times. It usually loosens things up a bit. Then see how dirty the fuel is that runs out. A good way to confirm or eliminate it.
In my experience a clogged filter has led to either bad running, or firing but running only for a few seconds, rather then no kick at all.
Thanks Everybody for lots of great suggestions. Now just need to find the time to work my way through them all. Got home late tonight and the car is in an awkward spot on the street, so really can only do much while there's decent light. Had bought some Start You Bastard at lunchtime, so thought I had time to give that a quick try. Took off the inlet hose and squirted into the plenum. Put back the hose and gave it a try. No difference. Tried again with a bigger squirt and still no kick whatsoever.
So, thinking that this proved the problem was spark I tried the next trick suggested of taking a lead off and putting a spare spark plug into it and seeing if it sparked on turnover. This would surely prove the case :). No such luck. the arriving dark showed the plug was sparking away quite nicely, at least until the battery decided I'd punished it enough for today. So, there's definately spark and Start You Bastard makes no difference, suggesting its not fuel.
Will have to think about that until I can get home earlier and have a better run at it to try some of the other suggestions.
Cheers
Take off the fuel line coming out of the fuel filter, and put another line from the fuel filter into a clear say 4 litre bottle, and have a fire extinguisher handy and switch on the ignition, you should hear the electric fuel pump run, and hopefully spit out some fuel into the container, if no sound, check fuel pump relay and fuse, if pump running, and no fuel, check for blocked fuel filter, if fuel filter is new or not blocked check fuel pickup in tank, it may be covered with rubbish or rust, and not picking up fuel, if you take out filter, you should be able to blow thru it with your mouth, before removing fuel filter lines, you will have to depressure them, remove fuel pump fuse or relay, and try and start the car, the fuel pressure in the lines will drop, and you will be able to undo the lines without being sprayed in petrol, Colin.
Check the connectors to the sensors on the thermostat housing, can't remember what they are called but if faulty she won't start. I had a similar prob where car was running fine and then stopped and wouldn't start, turned out to be a dodgy connection to the sensor causing it to run full rich.
Whilst sounding simplistic .. may I suggest you systematically check each of the major earthing points in terms of tightness and condition of the cable - particularly around the firewall area .. earthing problems have been one of the key issues in the GTV6 wiring area.
Out of leftfield maybe, but I'm all out of other ideas going by what you've said so far. You didn't park it on a hill with no handbrake I hope? I only ask because I've heard of them rolling backwards slightly and skipping a tooth on the belt.
Thanks for even more suggestions guys. Interesting one about the timing belt - no I never park without the handbrake on but when I felt the timing belt it seemed quite loose to me. Mind you, I have no idea how tight its meant to be (and as I said earlier, it was running great when I parked it.)
This is probably going to end up being some stupid thing that I haven't thought of or did wrong and I'll be quite embarrassed if that's the case. Nevertheless, shall push on and see what happens. Have decided to quickly try the few things left that might give a quick, easy result - change the dizzy cap and rotor button, check all wire connections and earths again with particular attention to the sensors on the thermostat, remove the cold start injector and see if it squirts.
If none of those do the trick, then I'll start on a more methodical overhaul of the fuel system, starting with the filter as suggested and going on to the fuel pump and injectors and then on to the ignition system. Probably won't be able to attack these properly until Friday or Saturday, so will post progress when I can.
Cheers (and thanks again)
Quote from: Albygtv on September 11, 2012, 03:49:13 PM
Thanks for even more suggestions guys. Interesting one about the timing belt - no I never park without the handbrake on but when I felt the timing belt it seemed quite loose to me. Mind you, I have no idea how tight its meant to be (and as I said earlier, it was running great when I parked it.)
About 10mm deflection between the pulleys (in my experience anyway).
Very strange that you have spark and it won't kick over with Start Ya' Bastard. And this is a new car, right? It doesn't have an immobiliser or anything silly?
Hey Sheldon, Ha ha, good one - your making me smile. Yeah, an immobiliser would be a great example of me having done something stupid, but I haven't found one on the car so far ;).
I'm pretty convinced that while the car has fuel and spark, one of them is below par. When I took the fuel inlet hose off and started the pump, it flowed but not any more than I've seen with non-EFI systems, certainly didn't seem like efi type pressure. Hence, my plan to start with overhauling the fuel components one at a time. That doesn't explain the non-starting with Start you Bastard. Maybe I need to try that again.
I've been through this a few times, and I seem to recall that it was about 1 litre of fuel per minute should be about normal with the AFM flap open? Don't quote me on that, I'm only going on memory. But I would have thought you'd at least get a kick from Start Ya Bastard. And, it shouldn't take much fuel pressure to get at least a kick anyway. I'm well used to the 'kick, and then dies after 2 seconds' problem, which is almost always due to low fuel pressure.
The fact that you can't get any kick at all suggests something other then fuel, and the fact that it won't kick with ether suggests that it is certainly not a fuel problem.
Otherwise, a loose wire somewhere would seem to be the obvious solution, I'd be checking everything very carefully. Seriously, these engines are as reliable as anything this side of a Toyota, I've had one of these sitting for about 5 years and it still started first crank.
I'm hardly one to be taken seriously after all the grief I've had thus far, but the first thing I would do, regardless of whether it fixes the problem or not, is change the fuel filter. $8.50 from MoParts in Croydon, or $15 from your local repco if that isn't nearby.
After I finally got my fuel issues sorted (with a "new" tank, new pump, new filter and new lines), it would take 5 or 6 seconds to fill a 600ml bottle (fuel line disconnected from the pulse regulator, which is mounted next to the double relay. On a 90 at least anyway).
While I was having issues (start then stall, missing, pinging, etc), the flow rate was much slower than this.
While you're changing the filter, it's probably also a good idea to just check the pump is getting a full 12V and has a good earth.
Got a timing light? Doesn't make sense as to why it would change since last driven, but another quick, free check that would be near the top of my list.
I recently bought a gtv6 a few months back and recently had similar issues with mine.
I experienced 2 separate problems at different times.
Before I did anything, I checked for loose wires, earth connectors etc, because like you I drove it the day before, it was running fine and i just parked it in the garage.
I was also looking to change fuel filters, spark plugs, leads etc.. but didn't need to go that far before I got it operational.
First time I experianced this the cause was the AFM, something was causing the fuel pump not to run, i fiddled with the flap and eventually got the fuel pump to run. It hasn't failed with this issue since and I'm driving the car a few times a week. My symptom was that the engine would start for about 5 seconds from start injector fuel but no fuel for piston injectors and the engine would die. If I pushed down on the throttle the engine would run for about 1 sec with fuel provided by start injector, if I didn't press on the throttle it would run for 5 secs before cutting out.
The Second time it was the lead on the very front of my cooling system thermostat, the ecu needs some sort of single back from the sensor on the thermostat for the engine to run properly. I had to clean the contacts and insert the plug properly to get the engine to start and run smoothly. The symptom was it would almost start and run but just would not idle and stall.
Hope this helps.
Marino
Just by the by, in my experience the car should start without the AFM connected. It'll run seriously rich but it will start.
Marino - that start/stall problem is well known and is usually symptomatic of a wiring issue. I can't recall the exact sequence but by memory the ECU needs to see the fuel pump working to fire the main injectors. The double relay in the engine bay drivers side rear plays a part - take the 12v feed to this relay away (it's fed from the main fuse box) and you can repeat the problem. Someone else will know the details for sure.
Double relay is one of the usual culprits. New replacements are available. If you aren't getting anywhere after a while, maybe change it too. I'd almost say in this situation New Filter & New Double Relay would almost be a no brainer (but it's not my money).
Aggie57 is almost correct, car will start without the AFM connected, you can also drive around without it. I drove 10km and every time I used over about half throttle it would miss. Popped the bonnet to find I 'd left the AFM unplugged.
Quote from: Al Campbell on September 12, 2012, 01:39:17 PM
Double relay is one of the usual culprits. New replacements are available. If you aren't getting anywhere after a while, maybe change it too. I'd almost say in this situation New Filter & New Double Relay would almost be a no brainer (but it's not my money).
The fuel pump is working though, so the double relay is fine. Also, as stated already, the car won't even fire with Start Ya Bastard, which pretty much eliminates any fueling problems.
Quote from: Sheldon McIntosh on September 12, 2012, 02:08:23 PM
Quote from: Al Campbell on September 12, 2012, 01:39:17 PM
Double relay is one of the usual culprits. New replacements are available. If you aren't getting anywhere after a while, maybe change it too. I'd almost say in this situation New Filter & New Double Relay would almost be a no brainer (but it's not my money).
The fuel pump is working though, so the double relay is fine. Also, as stated already, the car won't even fire with Start Ya Bastard, which pretty much eliminates any fueling problems.
Well then, back to basics: fuel, compression, spark. All three present and correct? If yes, she fires (well or poorly, but something kicks). If no, she won't.
Alby
Where are you located, maybe someone could swing by and help,
Sometime having 2 people there a diagnosis could be quicker
hey Dehne, I'm in richmond, Vic. Yeah, two people often work a lot better than one, but I'm a long way from giving up on this. In fact its a really great way to learn a lot more about these fabulous machines. (and I'm lucky that I have another car to use as a daily driver so the only time pressure is my own thoughts at any given time.
So tomorrow I'm going to tackle it very methodically and then we'll see where I've got to.There's a few simple suggestions I haven't tried yet and some bigger ones I'm happy to tackle if the simple ones don't work. Will report tomorrow night. Cheers
Well, made some progress today, although work interuptions kept wasting my time - don't they know what's more important?
Started by putting in a new battery as the old one didn't seem to be holding charge for long - tried starting engine, but no change to previous (that's abbreviated as BNCTP as I might be using it a bit).
Rechecked all wiring, especially around dizzy, coil, thermostat & firewall. Improved some connections and tested again. BNCTP.
Put a new rotor button in dizzy (type without an rpm over rev limiter - previous one had the limiter setup but limiter was taken out). tested BNCTP. Couldn't get a new dizzy cap but now have one on order,
Tried Start you Bastard again, BNCTP. This led me to test the fuel pump more thoroughly. Tried starting engine with air flap held open (to ensure it wasn't staying closed and therefore not triggering fuel pump) BNCTP. Pulled fuel line off inlet to fuel rail. Didn't seem to be any built up fuel pressure when I pulled line off. Started fuel pump with hose end in wine bottle (does owning old Alfa's result in more of these lying around??). Very good fuel flow out of hose. bottle half filled in seconds and fuel very clear and clean.
This all decided me that fuel is definately not the problem. Its flowing well (put my earlier test of this to it getting late and dark), can feel it in the lines, and more goes with Start you Bastard don't make any difference at all. So, it must be spark!!!!!
Did the "connect a spark plug lead to a spare spark plug test" again. No spark whatsover. Did it a number of times and couldn't get any spark at all. This same test showed a spark a few days ago, so either the new rotor button made things worse or the original problem has got worse. Went to test the coil as suggested and discovered its a MSD Blaster 2, whatever that means. According to MSD's website, the resistance should be Pri 0.7 ohms, Sec 4.7 K ohms. My readings were Pri 1.1 ohms and sec 5.5 K ohms. both outside the 10% margin but no clear info on the net as to whether they are too far out. Took off in Audi (never breaks down but very very boring) to buy new coil and try it. Just got back, totally out of luck in finding an MSD and an auto electrician told me I shouldn't use another coil if the car is set-up for this one. No idea how true / false this is.
Anyone know where I can get an MSD coil in Melbourne tomorrow?
That's it for today. Cheers
The MSD is a brand of coil, see if you can find out if the original coil is a resistor type, or non resister type, the resister type has a resister block, that has 12 volts going into one side, and the other side has the volts knocked down to say eight volts, this wire goes to the + side of the coil, then there is a second wire that comes directly from the starter motor, and when the starter motor is engaged, it sends the direct battery current to the coil, and this may be say 10 volts, so that the coil gives the spark plugs a big fat spark to start the car, but only when the starter motor is engaged, if you have a resister coil, then check the volts on the + side of the coil, also put a test light on the - side of the coil, and when the starter is kicking over, the light should flash on and off, Colin.
My three simple ones for the basics (fuel, spark, compression).
1. Fuel. On the drivers side of the plenum at the front are two small vacuum leads. Take either one off and spray some "Start Ya Bastard" in (gota luv that product).
turn the starter and if there is spark and compression IT WILL KICK.
So if you get a kick it is down to a fuel issues - my isses have all been around fuel pump realy from there. UIf you move the AFM vane with ignition on you will hear the pump, and the return valve sending fuel back to the tank.
2. Spark. ColCol and I were laughing about this yesterday - find a gullible friend and say " Hold This" while you crank it over. If his hair turns to Afro and he starts chasing you - you can be pretty sure there is a spark. If he just looks at you and says "What For" - dead spark it is.
If you dont have any friends that stupid I've used a timing light in the past as a spark detector. Hook in the top of the coil first and work it from there.
3. Compression. I have a compression tester but if you dont I suppose you could remove a spark plug and see if pressure comes out on start.
Obviously these are basic backyard dummy mechanic steps and apologise to anyone who is a trained mechanic.
I just work in IT and love fixing Alfas :-)
Catch ya
Shane
When kicking over GTV6, get a remote starter OR make one with a 12 volt switch, 1 wire to battery and the other wire to starter solenoid switch, [the terminal from the ignition switch], now you can kick the engine over from the engine bay, now take a spark plug and connect it to a spark plug lead, now go to the inside of the car and put the handbrake on OR put bricks or lumps of wood to chock your wheels, put it into neutral, switch the ignition on, now go to the engine bay and kick the engine over, while shorting out the spark plug against the engine, no spark, ignition problem, spark present fuel problem, Colin.
Eureka, have a runnuing GTV6 again. Difficulty seems to have been that there were two problems, one of which was intermittant, and possibly a third issue, being my ignorance of these cars and just how meticulous you have to be in narrowing down the possibilities.
Firstly, found a new MSD coil available in Dandenong, so shot out there yesterday and picked one up. Installed it yesterday afternoon and turned her over - didn't start but for the first time, sounded like it was trying to but just not quite catching. Definately had a good spark.
Had a rest and went back to it today. Exactly the same as yesterday, almost on the verge of starting but not quite. Tried some more Start you Bastard and with a few more turns it fired up. Hooray. When I touched the accelarator it died. Started it a few more times without needing Start you Bastard but each time I left it for more than a few seconds or touched the throttle it died. clearly now had a common problem that I've read a lot about in the last few weeks, so knew what to start checking. First thing was TPS but it clicked properly. Second was double relay and, sure enough it was not clicking or starting the fuel pump when opening the airflap with ignition on. I'd done this same test quite a lot of times in the past few weeks and it always worked fine. Now it wasn't working. Fiddled with the wires , no change. Fiddled some more and thumped the relay with my palm a few times - it started working. Started engine and it kept going and responded to throttle. - double hooray. Stopped and started a number of times and everything seemed fine, so just went for a 40 minute blast and the car ran great.
So, next weekend will have another look at the double relay and its wiring as this is clearly intermittant and therefore could happen again. Then its on to some of the things on my "improvement" list to keep me occupied over summer - might have to add a megasquirt to the list as it allows for future changes whilst possibly simplifying the underbonnet items a little. Can't wait.
Big thanks to everybody who responded with suggestions. I tried most of them and eventually got there and learnt a heck of a lot about these engines. All worthwhile. This is a great forum and a huge part of the pleasure in owning one of these cars. Big, big thanks.
MSD blaster is a replacement coil. Used one on my car.
I'd replace that double relay.
Starts but dies as soon as you touch the accelerator is a common issue. Unfortunately I can't remember what the cause is. Do some searching maybe on Greg Gordon's check list first.
AL.
Thanks Al. Yes, I've already ordered a double relay and will replace as soon as it arrives. I've also studied everything I can find on this condition and must admit that I'm a bit puzzled. The prime cause of the start then stops syndrome seems to be that the car starts on fuel from the cold start injector but stops when this stops because the other injectors don't kick in. There are quite a few reasons the main injectors might not kick in, and most of these are to do with the fuel pump not starting when its supposed to and getting fuel to them. The double relay is one of the reasons the fuel pump might not start, and others include various wires not connected properly or the AFM flap not opening, the fuel pump being s_____d and so on.
My question is, how does the cold start injector get its fuel if the pump is not starting? Does the pump run for a short period just on ignition to pressurise the CSI and then turn off and wait for the AFM flap to open to restart and pressurise the other injectors? Not very important really, but I'm curious.
The other thing that's happened is that I drove the car to work this morning through peak hour traffic. The idle on this car has been high since I got it - about 1400 rpm (and that's on my list for fixing this weekend). However, this morning whenever the car was idling (which was quite a lot in peak hour) it hunted or surged continuously between 1200 and 1400 revs. Ran perfectly above idle and the surging happened both when the engine was cold and when it was well warmed up. It did not surge when held at steady revs above idle speed. This is new - I'm sure it was not happening before the other non-starting issues. Again I'll be looking at this over the weekend but can't recall ever reading about it in the 100's of pages I've looked at so far. So, while its not desparate I would be interested to hear if anyone else has solved this problem previously.
hi there
I am, thinking off memory that if the cold start injector does not shut off this happens, i had that with my 90 years ago and my fix was just disconnect it. has been off for about 5 or 6 years now.
another thing is on the drivers side of engine rocker cover take all the bits off and clean them all they get gunk in them (cant remember tech names).
Wehn I have a prob like this I clean everything poss thats easy to get to, also new plugs, oil, and run some injector cleaner through to.
Alby - the fuel pump runs for a couple of seconds when the ignition is turned on and then stops. That is what provides the fuel to the cold start injector.
There is a signal out from the ECU to the double relay that is switched on when you start car. I can't recall what actually triggers it but recall it has something to do with the ignition. Once that signal is active there is a 12 volt supply to the double relay; voila - engine runs.
If the AFM flap stays shut the main injectors still get fuel. Just not much air!
My first guess for the hunting idle would be air leaks somewhere in the system. The other thing I would check is the throttle position sensor. Will take you about 5 minutes. The procedure for this is well outlined in Greg Gordon's L Jet guide.
My TPS wasn't adjusted properly. The car would start normally, idle perfectly at about 1k until you touched the throttle- then it would idle anywhere between 1 and 2k. After I adjusted it so that the sensor would read that the throttle was actually fully closed, it now idles perfectly. (and also doesn't hugely over fuel itself under mid range throttle because WOT was being triggered at about 30% throttle).
If the idle speed has been raised to get over issues of not idling whilst cold, you can reach a point where the L-Jet thinks it's on over run. Conditions are:
1. TPS switch is in "closed" posi. Revs are above "normal" idle. L-Jet thinks "O.K. you've just backed off, I'll cut the fuel to the injectors to reduce emissions."
2. Revs then drop until the L-Jet thinks "Uh Oh, idling and the revs are too low, better open up the injectors." Revs then increase until condition 1 is reached again. Happens when warm, revs ramp up then suddenly drop, then ramp up again. Round-and-round it goes.
3. I used to then go into a state of embarrassment at traffic lights as I sounded like a T***ser pumping the accelerator.
Other issue I had with idling was a clogged up "vacuum regulating valve" (only on Australian & Swedish cars" – picture attached). Took ages to find this was an issue. I think the oily goop blocks it when cold, then when engine is good & hot it leaks air back to the intake, raising the idle, maybe enough to cause hunting. The device is supposed to cut emissions in the event when you suddenly back off at high revs, causing too much vacuum? Given the amount of smoke my engine was blowing after 30 years I just disconnected the sucker and plugged all the holes.
AL.
Hey thanks guys for lots more good suggestions. And Al, your description of sitting at the lights feeling like a tosser was spot on - exactly the symptoms and the feelings I was getting.
Problem has quickly got worse with significant swings in idle rpm, so I won't drive it in heavy stop start traffic until its fixed. Amazingly still runs extremely well as soon as I hit the throttle. Anyway, its all made me realise that a good going over of everything related to the engine / fuel injection will be well worth while - after all, its all pretty old by now. So, should get the new double relay tomorrow and have just ordered a silicon vacuum hose kit from Greg Gordon. I plan over the next few weeks to look at all the suggestions you guys had and go through most of the processes Greg Gordon documents for getting the fuel injection working just right. Hopefully I'll then end up with a car that not only starts and runs well, but will keep doing so for a long time. (well, that's the hope anyway).
Will report after the weekend. Cheers.
I never really got on top of satisfactory idle during the warmup period from dead cold ~ first 5 minutes. Really need a replacement for the AAV, or replace the L-Jet. I had resistors in series with the heating coil in the AAV to make it warmup more slowly as first thing in the morning I was often sitting at lights with very short drives in between. I more or less had to reset the idle ever 4 months for the change in season. "What Cheese me Off!" is having to feather the throttle at traffic lights in a car with electronic injection. :P
Al.
One of the items on my list for this weekend is a good clean of the AAV. Hopefully that will help. I notice Greg Gordon goes in for manual AAV's so you don't have any problems but do have virtually a choke cable to pull out on cold mornings. I think that would also cheese me off on a car with electronic injection, but might be a last resort if all elsefails. Cheers
I tried two AAVs, cleaned them, adjusted them. Didn't make any difference. Little suckers never closed fully. didn't move a whole lot from frozen to hot. Saw a thread where someone pulled one apart recently. The long "shaft" holds the bi-metallic strip. The characteristics of the two metals must age over time, losing their temper (or work hardening) and the movement of the strip must be less than it was when new.
The Greg Gordon solution is a heater valve with a choke cable. I thought about making one with a temperature controlled actuator. Something like a Solenoid or R/C servo? There are also PWM controlled bi-pass valves available - saw one on a MegaSquirt Thread.
Good Luck,
AL.
Some good news and some bad news. Good news is that the idle hunting problem is completely cured (at least for today, fingers crossed, touch wood) - idle is now absolutely steady without a flicker of movement in the tacho needle. Engine even feels a bit smoother, crisper and more responsive at low revs.
Bad news is I don't know what fixed it. I could see my weekend was going to get away from me, so when I had a spare 30 minutes today I thought I'd just go and do a few basics on the car that were not likely to fix anything. but at least would provide a good basis for more work tomorrow. So went out and put on the new rotor cap I'd ordered, also the new double relay, removed the "vacuum regulating valve" as suggested by Al (although I discovered when looking at it that someone had already disconnected and plugged the inlet hose) and finally, did a quick adjustment of the idle to bring it down to more reasonable revs.
Then thought I'd take it for a quick drive just to see if this work had changed anything. Lo and behold, the result was as per the "good news" above. Of course, I'm very happy about this, presuming it lasts, but it would have been nice to know which item or combination of items caused the change. It might have even just decided to stop sulking and behave itself because I left it sitting unloved for a few days - although I think this is unlikely as I've read lots of threads relating to "running" problems and they never seem to fix themselves, no matter how long we leave them alone.
By the way Al, I'm going to look more into AAV's. There must be a better solution out there somewher. I've had some early 70"s Renault Gordini's and Alpine Renaults with the even earlier D-jetronic injection. Their equivalent of an AAV was very similar but instead of the electric warming, they simply had a section going down into the water jacket which heated up at the same rate as the engine. Sounds very simple, but they never seemd to give any trouble at all. even though they were 10 years older. Will see if I can find anything else.
Cheers
Alby - it will be the lower idle speed that stopped the hunting. It's really a simple system: above 1300 rpm with the throttle closed, ECU keeps injectors closed; below 1300 rpm with the throttle closed, injectors operate normally.
The idle bypass is like a mini throttle, bypassing the butterfly. So open it too much, revs rise above 1300 but because the throttle is closed, ECU shuts down injectors, revs drop below 1300, ECU operates injectors, revs start to rise, go above 1300 rpm, ECU shuts down injectors, and so on.
Hey Alistair. Thank you, that explains it perfectly & makes excellent sense to me. I'm actually starting to like this fuel injection set-up now that I'm understanding it more & more.
Thought I might do some more work on it today, but went for a short drive & then kept finding reasons to go a bit further. Ended up about 3 hours, hugely enjoyable & everything working really well. Boy these engines are magical - the sound & responsiveness just make me want to keep driving all the time. I love this car.
Cheers