Alfa 33 16v not starting

Started by 33racer, May 21, 2012, 07:09:06 PM

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33racer

Hi guys

Ive recently built a 1.6 16v motor for my race 33 but im having trouble to get it started its got spark and fuel getting to it. and it combusts the fuel every now and then but usually as a big flame out the exhaust pipe. Does anyone know what is wrong or how to fix it. ive also tried changing the timing but nothing. also atm im just using the standard motronic ecu.

Any help appreciated

Regards
Steve

colcol

I was told when i was an apprentice,[shortly after the invention of electricity], that there are 3 reasons a car will not start, 1. no spark, 2. no petrol, 3. no compression, you say you have spark, and there is fuel, how about compression?, do a compression test, [i know that is difficult in a 16 valver], and see how it looks, also check your timing belts are timed right, they can be timed ok, so the valves don't hit the pistons, but they can be 180 degrees out, as i found out once, it would fire, but not run properly, also, have everything at Top Dead Centre, and see if you look like you are getting spark, just take off ignition lead, and bump it over by hand, to make sure you are getting a spark around Top Dead Centre, by removing spark plug and shorting out to see for spark, Colin.
1974 VW Passat [ist car] 1984 Alfa 33TI [daily driver] 2002 Alfa 156 JTS [daily driver]

Frank Musco

Steve

I second the distributor being 180 out. Cross the leads opposite to each other and it should start if that's the problem.

Was the car running well before you built the race engine?

I'm very interested in what you've built. Should get some very scary high revs out off it! I've considered building a de-stroked 1700...one day...

good luck.

colcol

Also make sure your starter motor is kicking the engine over at a fair rate of knots, if it cranks too slow it will be hard to start, as Frank said, try bringing the no1 piston to Top Dead Centre, and seeing where the rotor is pointing, it should be to no 1 or 180 degrees opposite, remove distributor and turn the distributor 180 degrees, and see if it will start, if i remember rightly, the 16 valver doesn't have a hall effect triggering setup in the distributor like the early 8 valve 33's, but is triggered by a crank sensor, is that correct?, Colin.
1974 VW Passat [ist car] 1984 Alfa 33TI [daily driver] 2002 Alfa 156 JTS [daily driver]

colcol

A big flame out the tailpipe indicates timing, belts or distributor being out, i know cause i have been there myself, Colin.
1974 VW Passat [ist car] 1984 Alfa 33TI [daily driver] 2002 Alfa 156 JTS [daily driver]

33racer

Thanks for all the help. Ok the timing was 180 degrees out and i do have plenty of compression but now its trying to start but it just wont stay started.

33racer

OK i got it working now it was the rotor in the dissy was really worn and it was making it spark all the time.

Thanks for all the help.

Regards
Steve

Alfapride

can an ECU be disassembled and rebuilt or is it a sealed unit??
Alfa 33 16v
Alfa 116 Giulietta
Alfa 116 Alfetta GTV
Alfa MY2004 147 TI
Alfa MY19 Giulia Veloce

colcol

There are people that rebuild ECU's, Google it, and see what you come up with, get a price on a new one or change over one first, someone might have NOS sitting around, Colin.
1974 VW Passat [ist car] 1984 Alfa 33TI [daily driver] 2002 Alfa 156 JTS [daily driver]

Alfapride

thanks Col, depending on whats in them I might have a go myself, I can solder and replace parts in electronics pretty easily.
Alfa 33 16v
Alfa 116 Giulietta
Alfa 116 Alfetta GTV
Alfa MY2004 147 TI
Alfa MY19 Giulia Veloce

festy

The ECUs in these are pretty simple devices compared to "modern" ECUs - two 2-layer PCBs with a mixture of PTH and SMD components. Almost all semis are PTH, only some of the resistors and caps are SMD.
The problem will be that it uses a few custom Bosch ICs, so you can't get generic replacement parts for some of them.
What's wrong with your ECU though?