928 s4 starting problem

[morris]

Hi All

I need some help with my 928 s4 and would be grateful for any hints or tips.

1928 s4 / petrol / automatic / 95k miles/ 4957 cc/ RH drive/ registered 1989.

I have owned this car for four problem free years until last week when the following problem occured.
Tried to start the car and it would start, then gain and loses revs without my intervention ,.i.e. erratic increase and decrease. When I depress the accelerator it would react and the revs would increase momentarily then fall and stall or rather oddly depressing the accelerator would cause the revs to drop off altogether. I did manage to get any sort of consistency in the revs as soon as I put it into gear the car stalls.

Failing any suggested solution I would be grateful if any one could recommend a Porche garage in East Sussex other than Paragon who are good, but too pricey.

 

[rawky]

Hi There,

There are several places to look if you struggle here. There is a person in the Porsche Club who's technical advisor for the 928. His number is in the little book you get with membership. You could try Paul Anderson, who just services 928s everyday. His number is at 928spares.co.uk
You could also try Rennlist.com, this is an American Forum but there are alot of people who are very clued up on there.
I can't shed any light myself but that's the way to go about asking around

Hope this helps,
Cheers

 

[924nutter]

When I had my 928S4, I had this near identical problem on the M40 except I suddenly lost power. When I pulled on to the hard shoulder the engine would start and idle with fluctuating revs but would stall everytime I tried to pull away. I had to trailer it home. It turned out to be low fuel pressure caused by too little fuel in the tank. The swift insertion of a gallon of petrol cured the problem. If your reserve light is on then its got to be worth a fiver to see if that cures it.

 

[nathan 1981 930 G50]

Just guessing really, but I'd take a look at the hot wire MAF.

 

[Gary C]

or look for air leaks, split hoses on the inlet after the maf.

Check fuel pressure at the injectors (be carefull on that one, high'ish pressure), look for an inline fuel filter and check for fuel blockages.

Throttle position sensor ?

Unlikley to be ignition but you can't really rule anything out yet.


The hunting it probably the idle speed control trying to get control, the loss of revs when you open the throttle is probably more airflow thats not being metered (split hoses or failing MAF) and therfore not enough fuel is being injected, or the fuel system is faulty and only giving enough fuel for idle and cant manage any load.

Did it happen suddenly, then its probably a single component failure.

 

[johnk]

had one the other week where it would start then drop off, turned ignition on injectors clicking away and no fuel pumps... turned out to be the lh ecu faulty.. repaired and jobs a good un...