Alfa Romeo Owners Club of Australia Forum

Technical => 932 Series (156, GTV, Spider, 147, GT, and 166) => Topic started by: Citroënbender on February 12, 2018, 08:19:45 AM

Title: Accumulator Health Testing
Post by: Citroënbender on February 12, 2018, 08:19:45 AM
Trying to sort something by remote control here...

With a healthy accumulator, if the car has not run, but ignition is on and the driver's door just opened, how many gears should one be able to row through (with just a brief pause, forward gears only) before the pump kicks in?
Title: Re: Accumulator Health Testing
Post by: bazzbazz on February 12, 2018, 09:37:30 AM
2-3 gear changes.

If the pump runs at every change Accumulator is on its way out.
Title: Re: Accumulator Health Testing
Post by: Citroënbender on February 12, 2018, 09:51:11 AM
Ta. SWMBO is complaining she has to manually shift, the car won't go from 2-3 (etc) as normal in City mode - so I'm presuming it's delaying the upshift due to lack of stored pressure. No fault messages or warning lights. Being three weeks away I'm trying to diagnose so the neighbour can repair under instruction.
Title: Re: Accumulator Health Testing
Post by: bazzbazz on February 12, 2018, 05:26:59 PM
More than likely it is a loose "Pinch Bolt" (bolt that connects the Selespeed Actuator to the gear box selector shaft)

When it comes loose it starts to cause the gear changes to fumble & stumble. Make sure it is tight, check the clutch rod length and then give it a calibration and hopefully all will be good.
Title: Re: Accumulator Health Testing
Post by: Citroënbender on February 12, 2018, 09:55:28 PM
Struth, I guess better to be prepared than caught off guard. The actuator bloc was dealer-new about 110K (mostly highway) ago, circa 2012.
Title: Re: Accumulator Health Testing
Post by: Citroënbender on February 14, 2018, 10:10:50 PM
OK, accumulator passes the rough test; 1-2-3-4-5 shift without hesitation when just opened up and keyed on, motor off.

I'm almost wondering if it's a dying crank sensor; age is about right. 
Title: Re: Accumulator Health Testing
Post by: bazzbazz on February 15, 2018, 01:14:02 AM
If it is loose pinch bolt it will only do it when driving.

Usual symptoms is that as the car is driving in City Mode, as it goes to shift from say 2nd to 3rd, it's like it can't find the gear, hunts for it for a moment, buggers around then skips to 4th, or until the driver intervenes and does a manual command of some sort.

Does this sound like the trouble in hand?
Title: Re: Accumulator Health Testing
Post by: Citroënbender on February 15, 2018, 05:38:16 PM
I cut and pasted your description, apparently it was spot on, had also neglected to tell me that when it was not upshifting the "2" was flashing... 

Can the pinch bolt be practically re-used with threadlock or is it a stretch bolt? Also, can it be got at through the nearside wheelarch with the splash shield off?
Title: Re: Accumulator Health Testing
Post by: bazzbazz on February 15, 2018, 06:22:04 PM
Always use a new Pinch bolt, the are a couple of dollars from any specialist bolt supplier. (Bolt King ect)

Yes, you access it through the wheel arch, to make lining up on it easier drop the gearbox down slightly by undoing the main mount bolt.
Title: Re: Accumulator Health Testing
Post by: Citroënbender on February 25, 2018, 02:48:31 PM
Apparently the pinch bolt was solid as; a trusted mate (Renault repairer) had a good look.  The other relief was no Sele oil in the void, so the O-rings are OK. (Phew!)

So - ignoring oddities like shift fork/detent/damaged syncro problems, I'm back to NFI.  :(

I did find this (not really related), had a good laugh at Fleabay auto-translating listing number 152906764204...
Title: Re: Accumulator Health Testing
Post by: bazzbazz on February 25, 2018, 03:02:59 PM
I assume you are not at the same location as the vehicle?
Title: Re: Accumulator Health Testing
Post by: Citroënbender on February 25, 2018, 03:16:22 PM
No, 1400km away!
Title: Re: Accumulator Health Testing
Post by: bazzbazz on February 25, 2018, 10:09:14 PM
Great, so I am doing "The Great Swami" impersonation via a 1400km relay . . . . . you DO make things difficult don't you!  ::)

;D ;D ;D
Title: Re: Accumulator Health Testing
Post by: Citroënbender on February 25, 2018, 10:19:55 PM
Well, if it was easy, you'd surely hope I didn't need any help.  :P
Title: Re: Accumulator Health Testing
Post by: Citroënbender on March 22, 2018, 12:05:18 AM
OK, had a chance to observe some of the Sele mischief first hand. It is only doing even gears.  ???
Title: Re: Accumulator Health Testing
Post by: bazzbazz on March 22, 2018, 01:48:34 AM
That means it should not pass the EOL Calibration, correct?

Replace the Back & top sensor (Gear selection & Gear engagement sensor) then do EOL calibration.

Test drive then do clutch calibration.
Title: Re: Accumulator Health Testing
Post by: Citroënbender on March 22, 2018, 07:29:10 AM
Thanks Bazz,

As presenting it definitely shouldn't pass the EOL calibration; agreed.

Given there's no "one stop sensor shop" close by, will swapping the sensor positions move the fault to create a different symptom?

It's currently less than ten degrees and raining, hopefully that will improve before I get under the bonnet!
Title: Re: Accumulator Health Testing
Post by: bazzbazz on March 22, 2018, 10:27:09 AM
Do any errors come up on diagnostics?
Title: Re: Accumulator Health Testing
Post by: Citroënbender on March 22, 2018, 11:06:36 AM
No, none and none in the motor ECU either.  :o

Checked console lever on parameters and it shows forward, backward, reverse instruction as received, no paddles to check.

Hydraulic pressure seems OK, reporting of pump relay action a bit flaky.

Presently got battery neg off.
Title: Re: Accumulator Health Testing
Post by: Citroënbender on March 22, 2018, 11:37:42 AM
Observed that pressure seems to drop very low (36-odd bar) before pump starts, and once pressure is restored the shifts seem OK. Pump doesn't even start automatically when the pressure is this low but takes a while to kick in.

Could this be a faulty pump?
Title: Re: Accumulator Health Testing
Post by: bazzbazz on March 22, 2018, 03:04:48 PM
Faulty pressure sensor.

Check & clean connector & sensor or you'll need to cannibalise a working one from wreckers.

Still is not the reason for not engaging odd gears, that will be most likely sensors or loose Pinch Bolt.
Title: Re: Accumulator Health Testing
Post by: Citroënbender on March 22, 2018, 04:08:57 PM
The pinch bolt checked out as good and tight. I checked the harness connections to the sensor pots, all seemed snug.

I'd been thinking it may have become a "chicken and egg" situation where a flat sphere was overtaxing an aged pump. Hadn't really considered the pressure sensor.
Title: Re: Accumulator Health Testing
Post by: bazzbazz on March 22, 2018, 10:05:03 PM
Understand that, but the pump is supposed to engage at 45 Bar and its condition is irrelevant as to when the pump relay is closed and power is sent to the pump. I have come across this problem before and a replacement pressure sensor always solves the problem, as long as the replacement sensor is in working order of course.

Once the pump has primed, you get 2-3 gear changes before the pump runs again, yes? What pressure does it stop at when repriming the system, should be around 55.

If you are concerned about pump condition use MES to continuously run the pump, this should reveal any issues.

Again, this still is not the reason why it's only engaging odd gear.

Title: Re: Accumulator Health Testing
Post by: bazzbazz on March 22, 2018, 10:25:48 PM
Quote from: Citroënbender on February 15, 2018, 05:38:16 PM
had also neglected to tell me that when it was not upshifting the "2" was flashing... 

This indicates and electrical error or some sort.

Just to clarify, have you done an EOL and did it pass ok?
Title: Re: Accumulator Health Testing
Post by: Citroënbender on March 22, 2018, 10:49:08 PM
I tried to run another EOL and it failed to proceed after the first fifteen seconds or so. Couldn't do screenshots this morning as the phone went flat...

Pressure dropped faster than I'd expect with a healthy accumulator, two shifts and it was dipping to 42 bar or something. The pump does stop at 55 or so, but there is a fast drop of a bar or more.

I popped the relay cover to manually bridge the contacts and ran the pump up to slightly overpressure, listening to its note. Didn't seem to change appreciably or greatly heat up the contact wafer in the relay.

Will see if the sensor crosses to anything else I might find more readily, there's apparently one other identical car around but I doubt they'd loan me critical parts for a swap test.
Title: Re: Accumulator Health Testing
Post by: bazzbazz on March 22, 2018, 11:21:30 PM
2-3 changes is all you will get from a good Accumulator. Time it from full pressure till it gets to 45 bar and let me know.

If the pump runs with every gear change it is cactus.

When you get a chance run the EOL and let me know what errors/faults it shows up.
Title: Re: Accumulator Health Testing
Post by: Citroënbender on March 23, 2018, 08:22:36 AM
Thank you again.

I'm trying to cross the sensor, is it P/N 71719383?

Actual work needs to be suspended until Tuesday as my konfetka has a significant birthday this weekend and we're in the throes of mad preparation with a forecast of possible heavy rain...  ???
Title: Re: Accumulator Health Testing
Post by: bazzbazz on March 23, 2018, 10:09:18 AM
"cross the sensor"  . . . . .Huh?   ???
Title: Re: Accumulator Health Testing
Post by: Citroënbender on March 25, 2018, 03:28:55 AM
Meaning, to check the part number for broader applications, as in possibly later variants of Selespeed or actuator assemblies of other marques. There's probably just one other 147 Sele in this one-horse town.

(That said, I do regularly see a black 159 with the personalised plates 159JTS getting around.)
Title: Re: Accumulator Health Testing
Post by: Citroënbender on March 28, 2018, 09:31:41 AM
Pressure sensor replaced. Only a minor "douche vert" was enjoyed.

Would appreciate confirmation on two points, please.

1. The PF7C pots are now PF2C
2. Nominal track resistance is 1200 ohms

Thanks!
Title: Re: Accumulator Health Testing
Post by: bazzbazz on March 28, 2018, 01:21:19 PM
Yes 1200 ohm
Title: Re: Accumulator Health Testing
Post by: Citroënbender on March 28, 2018, 03:55:24 PM
The replacement pressure sensor from Monza showed near-identical outcomes with MES as compared to the old one. It was interesting to note the physical differences in their bodies; one had a 14mm hex section abutting the thread, whilst the other was 22mm.

Here's three successive pump cycle times. I measured by prising the cover off the pump relay and observing the contact leaf's movement; timing from pull-in to next pull-in.
Title: Re: Accumulator Health Testing
Post by: bazzbazz on March 28, 2018, 11:07:16 PM
Yes but does the pump now reprime the system at 45 Bar and shut off at 55?
Title: Re: Accumulator Health Testing
Post by: Citroënbender on March 28, 2018, 11:18:39 PM
According to the readout, the pump seems to kick in around 44 Bar and shut off just over 54.

One only gear change is almost certain to drop the pressure enough to cycle the pump.
Title: Re: Accumulator Health Testing
Post by: bazzbazz on March 29, 2018, 12:10:32 AM
Ok, then that's has fixed the pressure dropping down to 36 bar and the pump not restarting, that's one problem fixed.

If the pump is running at every gear change then the accumulator is worn and not holding pressure well. A good one you will get 2 changes before the pump running, a brand new one you'll get 2-3.

Be aware, with the accumulator wearing out it also causes extra wear on the pump brushes (runs ever gear change instead of every third), AND the pump relay. I always recommend when replacing the accumulator to replace the pump relay and replace the pump/pump brushes. Otherwise I guarantee sooner or later the pump brushes will wear out and stick and your partner will be cursing and swearing your name when she is stuck in the middle of a intersection in peak hour.   ;)
Title: Re: Accumulator Health Testing
Post by: Citroënbender on March 29, 2018, 07:43:26 AM
Ah, the joys of old age; to hear her moaning my name again...  :P

Good point about the pump now kicking in consistently.

I'll get an accumulator ordered up today. The real plus in this, is I'll finally know the thread and be able to make an off-car testing adaptor for them using a Citroën sphere tester. With the motor, I'll check the pump motor brushes on my "bacio di legno" car and either refurb or straight swap it. Relay contacts actually look good and socket connectivity is fine; I've checked them.
Title: Re: Accumulator Health Testing
Post by: Citroënbender on April 04, 2018, 01:26:42 PM
Mixed results with new accumulator. Massive increase in standing cycle time to over nine minutes; about three times the prior result. Can shift up to three times before pump starts up.

However I can still make the pump not run by loading up its duty cycle. Then it won't pressurise, and the dash offers a "Selespeed System Failure" warning, the pump refuses to run and starting is not possible. Sometimes even keying off and letting stand doesn't seem to resolve it, although bridging the pump relay initially to start, can get me around the issue.

So... I think there is a pump refurb coming up quite soon!

Edit: I did get the clutch down to 28.014mm though. :D
Title: Re: Accumulator Health Testing
Post by: bazzbazz on April 04, 2018, 05:09:52 PM
It's most likely in need of a rebuild. As stated earlier, when the accumulator starts to fail it needs the pump to run almost every gear change to keep up the pressure, thus the pump is being continuously run all the time instead of every couple of changes, thus exacerbating the brush wear.

If the accumulator fails, the pump usually fails soon after, one leads to the other.
Title: Re: Accumulator Health Testing
Post by: Citroënbender on April 04, 2018, 05:46:00 PM
Is it worth trying to undercut the commutator or would that just be wasting time?

Are the brushes 6.35x8x18mm or 8x9x22mm? I've seen both offered as fitting.
Title: Re: Accumulator Health Testing
Post by: bazzbazz on April 04, 2018, 06:38:08 PM
8x6x whatever and trim to fit.

Larger brushes will work, just more filing to do.