Porsche Enthusiasts Club Forum

hello there, im new to this fori,, im currently on my second s4 1991 which I love.
I have a terrible problem that I cant seem to cure and heres what happens,

I can be driving for 30mins and everythings ok cars running great then all of a sudden the car starts missing an I loose power and eventually will cut out, its almost like theres something blocking the fuel lines, I have had the lines cleaned and thats been elimiated but the problems still there.

A couple of things have been modified, Im now using the xpipe system so the cats gone, the service center has mentioned it could be the cat sensors and have suggested taking them out, apparently because the car will sense its no there and run off 4 cyclinders not 8.

I dont think its that, in the history of the car back in 2004 one of the owners has complained of the same problem so im not sure if its ever been fixed.

Ive also had the sports button fixed from jager engineering (allows to start in first rather then 2nd) im not sure if its that, also when it happened this time I was using the air con could it be something to do with that?

I have had this car only from november 09 so this is the only the real fault that I have encountered since I have had it, although there was a problem with the fans not working to cool the engine down which is now fixed which was a wiring problem.

Im hoping that someone can shed some light on this one, its a really dangerous one and im starting to loose confidence in the car

thanks

john

Hi

What happens why you try to RESTART it after its cut out ?

And when did you last CHANGE the dizzy caps , rotor arms and plugs ??

And I mean CHANGE ...not check.....

All the best Brett

hi brett,

thanks for getting back, when i restart the car with in a few seconds, the problems still there, if i leave it it goes,

When I left the car for the rac to tow it to the garage they started it up and drove it 30 miles straight there and there were no problems

the plugs were changed at the last service but the rest i have not changed, i guess your suggesting to do that too,

best wishes
john

brettt forgot to say that it does not cut out straight away its like all the power goes and then will eventually cut out

Hi John

Yes, change the dizzy caps and arms anyway...

To me it sounds like a fuel starvation problem...you realise there is a fuel injection filter under the back next to the pump (under a cover plate) if this is blocked through age it could easily give your problem...

I change mine every 2 years (16,000 miles)

So things you need to CHANGE not check to eliminate them all (plus the car will go better anyway)

INJECTION FILTER
AIR FILTER
DIZZY CAPS
ROTOR ARMS

Do all those and let us know if it continues....

All the best Brett

hi brett,

will do, thats brilliant advice many thanks,

its at paul andersons at the moment, so i will ask him to sort that

warm wishes
john

Hi John

Well if Paul has it..it WILL be cured lol...he is the BEST bar none on 928`s

But get him to change those bits anyway as they do need doing ...

All the best Brett

hi brett,

i will ask him to change it, hes had it already in dec with the same problem and he thought it cured it he found the fuel lines at the back where the tank were blocked and the tank had dropped too, but the faults still there, its just a process of elimination now,
will keep you posted, its really great to get other views on this stuff especially when it can cost so much

best

john

Did you check that the fuel tank vent was not blocked?

The most likely problem is a relay, fuel pump, EZK or LH. Paul will know this. Here's a link to fault finding a no start -

http://www.jdsporsche.com/fault%20find.html

no will check that too thank you

john

thank you will mention that too, its brill to get this help

john