Any ideas on this anyone ?

[peanut]

If I leave my S2 for 3-4 weeks its a devil of a job getting it started again. Once warmed up and used for 50 miles or so there is no further problems starting for a week or so.

I have narrowed it down to fuel delivery and specifically the injectors I think.

I was checking that the injectors get an electrical pulse and found the connectors all gunged up with something ?

I thought it might be some sort of electrical contact laquer or maybe just the plastic has melted due to excess current ?

Any ideas ?

ps DME is fine fuel pump and filter are fine all plugs, dizzy rotar etc etc are fine the problem is definitely fuel delivery or lack thereof

 

[sweetpea]

Hi Nick,

Just looks like grease to me... which shouldn't really pose a problem.

What does it smell like??

Mike []

 

[mik_ok]

What sweetpea said - looks like someone has loaded it with grease to keep moisture out and stop it corroding - and it appears to have done the job perfectly. [8D]

You need to look elsewhere for the problem.

 

[peanut]

ORIGINAL: mik_ok

What sweetpea said - looks like someone has loaded it with grease to keep moisture out and stop it corroding - and it appears to have done the job perfectly. [8D]

You need to look elsewhere for the problem.

the problem is definitely one of fuel delivery .

It is not grease .

It is very hard and crystaline and I cannot remove it with a sharp spike. Its as if the glue that the spade connector is set into has melted in heat then reset .
I'll check the resistence of all the injector feeds and book the injectors for a clean and test after christmas

ps I'll go and smell it in a minute when I've finished my cuppa ![]

 

[944 man]

My guess would be that youre losing stored fuel pressure. If there isnt sufficient fuel pressure in the fuel rail then the car will struggle to start.

 

[peanut]

yes that was my first thought also a possible blocked filter or leak on the pump side but there is fuel in the fuel rail. I checked the fuel pressure whilst cranking by undoing a fitting on the fuel rail. There is fuel there and it is pumping ok but possibly with insufficient pressure .

I'm still inclined to think the injectors are at fault because when she finally does catch it is only with 2x cyclinders. I have to continue to crank the starter motor whilst the engine fires on 2x then 3x cylinders and finally after 2-3 minutes of cranking and much coughing 4x cylinders.

Its not zero fuel but possibly insufficient fuel or pressure or possibly gunged up injector nozzles methinks

 

[mik_ok]

ORIGINAL: peanut

It is not grease .

It is very hard and crystaline and I cannot remove it with a sharp spike.

In that case - no it's not grease, thererfore it's not normal, therefore you should replace that connector block. []

 

[Fen]

I can't see it being the fuel filter. Both logic and experience tells me that if the fuel filter is partially blocked you get problems at high revs where fuel flow is high, not at idle/starup where it is low. Of course it could prevent the car starting, but I bet it would make it impossible to start, not just difficult.

 

[peanut]

a

ORIGINAL: Fen

I can't see it being the fuel filter. Both logic and experience tells me that if the fuel filter is partially blocked you get problems at high revs where fuel flow is high, not at idle/starup where it is low. Of course it could prevent the car starting, but I bet it would make it impossible to start, not just difficult.

quite right Fen I bought a fuel filter just in case but before I fitted it I managed to get it to start ,as you say the evidence doesn't suggest fuel filter as once started ,it runs perfectly without a single cough or splutter right up to 5500rpm .
this also eliminates the pump being implicated of course.
The only other thing that could be a contributary factor I can think of is the cold start components.

 

[homesea]

Just thinking from a totally different angle, how about oil sat in the bottom of the cylinders?? This would make starting difficult and if you have bad steam seals oil can get passed.

 

[peanut]

ORIGINAL: homesea

Just thinking from a totally different angle, how about oil sat in the bottom of the cylinders?? This would make starting difficult and if you have bad steam seals oil can get passed.

you lost me there somewhere Tom ?

Do you mean difficult starting due to slow cranking ? My S2 spins the engine like a washing machine on spin cycle. Its very fast due to additional earth strapping throughout the car.
This problem is definitely fuel related

 

[homesea]

Sorry, thinking of two things at once.

1)Valve stem seals stop oil running back down the valve stem into the cylinder when the engine is static, so if they let a lot of oil past then it could make starting difficult(but would have to be a lot of oil).
2)I not sure about the S2 head setup but on some 16v engines as the spark plug is vertical, if the rocker cover gasket is shot it can let oil run down onto and past the plugs and you get a weak spark, also can rot the ends of the plug leads so the leads ark onto the head and you get a weak spark.

It was only an idea.[]

 

[homesea]

Just had another idea, old Golfs sometimes had ECU fail and this would leave the injectors on all the time so would get to much fuel in, and not start. Have you tried keeping your foot to the floor when starting?

 

[zcacogp]

I can't diagnose the problem, but having had similar problems with a 928, I'd recommend finding an oscilloscope and a good digi volt meter and testing everything logically, using a circuit diagram. It is time-consuming but not laborious, and if you are of a logical persuasion then it is very satisfying.

We spent nearly a day finding a duff relay that controlled the injectors on the 928, but there is a LOT more wiring in one of those than in a 944.


Oli.

 

[peanut]

its not electrical fault guys honestly its a fuel,air petrol injector related problem
.
The injectors are receiving pulses as they should but there is a shortage of petrol reaching the cylinders.

heres what happens ,pay attention at the back
.
turn engine over continuously for 1-2 minutes without releasing key.
No cough no splutter absolutely no attempt at firing.
Check spark to all plugs ....perfect.
Check pulse to all injectors ..perfect
Check fuel rail full of fuel and being pumped ...perfect
However No fuel on plugs ....!
Pump the throttle like crazy eventually get slight cough and fires on 1x maybe 2x cyclinders.

Keep continuously cranking starter whilst pumping the throttle like a demented tap dancer.
After 2 minutes of cranking and pumping Engine begins to fire on 2x then 3x cyclinders.
finally stop cranking starter and pump throttle and engine picks up slowly clearing throat and fires hesitantly on 4x cylinders.
Warm her up pull away and perfect running in all respects right up to take off speeds.

Next few days catr starts on the button runs perfectly.

leave car for 2x weeks back to same problem.[&o]

 

[peanut]

ORIGINAL: zcacogp
there is a LOT more wiring in one of those than in a 944.


Oli.

tell me about it Oli. I spent half of my life upside down in the passenger footwell wrestling with the fuse relay board of my 89 928 last year.
Did you know that the early 928 was the first car to have central locking and it was controlled by vacumm with little rubber pipes going to the door locks ![]
that relay controlling the injectors is the infamous DME relay

 

[zcacogp]

Nick,

No - the injectors worked by being fed +12v all the time, and the ECU grounded out the other link whenever necessary, thus firing them. The relay which failed was the one which switched +12v to all of them ... thus no injectors worked, although all appeared to be being switched correctly.

It didn't look like a DME relay as I am used to ... it was a standard 4-leg thingie. (And it was only a matter of chance that the duff relay was plugged into that hole in the fusebox when the car was rebuilt, which is what we did two months earlier! We cured the problem by swapping it for the one from the horn.)


Oli.

 

[Fen]

ORIGINAL: peanut

its not electrical fault guys honestly its a fuel,air petrol injector related problem
.
The injectors are receiving pulses as they should but there is a shortage of petrol reaching the cylinders.

heres what happens ,pay attention at the back
.
turn engine over continuously for 1-2 minutes without releasing key.
No cough no splutter absolutely no attempt at firing.
Check spark to all plugs ....perfect.
Check pulse to all injectors ..perfect
Check fuel rail full of fuel and being pumped ...perfect
However No fuel on plugs ....!
Pump the throttle like crazy eventually get slight cough and fires on 1x maybe 2x cyclinders.

Keep continuously cranking starter whilst pumping the throttle like a demented tap dancer.
After 2 minutes of cranking and pumping Engine begins to fire on 2x then 3x cyclinders.
finally stop cranking starter and pump throttle and engine picks up slowly clearing throat and fires hesitantly on 4x cylinders.
Warm her up pull away and perfect running in all respects right up to take off speeds.

Next few days catr starts on the button runs perfectly.

leave car for 2x weeks back to same problem.[&o]

Sounds like too much fuel rather than too little to me.

 

[Hilux]

Seems you are unable to maintain fuel rail pressure until pump eventually primes it? (Dont know if there is a non return valve however)

Try letting fuel pump prime for a minute or two before starting it?

Is the pump tired or partially blocked?

New filter or original? (old one may have collapsed internally)

Old rubber fuel pipes? They can balloon inwards if delaminated so as pressure increases it enlarges the blockage? (same with old flexy brake pipes)

An odd suggestion but you havent clouted the fuel pipes on a speed hump?

Air/engine temp sensor fault means the ECU sees a `warm' engine?

Just a few abstract suggestions, good luck.

 

[peanut]

ORIGINAL: Fen



Sounds like too much fuel rather than too little to me.

if it was too much I would expect the engine to fire the excess fuel in the exhaust after 2 minutes of continuous cranking. When she finally fires there is no smoke which i would expect from an over rich engine starting.
I'll recharge the battery tomorrow and clean the plugs and try again. I'll check the plugs after cranking to see if they are dry or wet .
I might try to get hold of some high octane starter to spray in the intake see what happens

remind me of the cold start apparatus on a N A could it be effecting the mixture that much ?