Wsp964

Since a few weeks I've got those weird idle and stalling probs !

Each time I reach the 1/4 gastanklevel and lower, I experience idle/ hesitation problems ... the engine hunts like crazy and often stalls. This happens with a cold and hot engine.

After I fill the gastank the problems fade away till I reach the 1/4 level again.

Obviously the idle probs are related to the gassystem, but what exactly can be wrong ? I already used petrol additions to clean the engine but that doesn't seems to help. I did not changed the fuel filter for the mom. Guess the gastank with time got dirty or maybe it had some waterinfiltration .....

Anybody any idea what to do ?

Thanks! <img src="graemlins/wave.gif" border="0" alt="[byebye]" />
WSP964

C4 1989, 75.000 km.

Adrian

I would recommend that you change your fuel filter, completely flush the fuel system and stop using fuel cleaning additives. I would also recommend you check the fuel sender system. Does your low level fuel warning light actually work. Easily checked by turning ignition on.
I suspect this is a fuel gunk and pickup problem. The only way to fix it is to have the whole system cleaned throughly.
Ciao,
Adrian
911C4

Ade - C4 91

Hi,

Adrian is quite correct, and I would also suggest that you may have a failing fuel pump, perhaps get your fuel pressure tested. With a full tank the fuel pump has to do less work as the pump is below the tank and is helped by gravity, this can mask the problem.

It's a pig of a job getting the pump out as access is very restricted (couldn't they have made the hole a little bigger?), so I suggest you get your mechanic to do it, if this is the problem.

Good luck

Ade.
91 C4

Wsp964

Thanks guys ... appreciate the help.

By the way this board is really amazing ... quick and good respons ... not only do we have the best car in the world but also the best board on the world wild web !!

Cheers to that <img src="graemlins/beerchug.gif" border="0" alt="[cheers]" /> (belgian beer!)

WSP964

Ade - C4 91

Hi,

No prob. Let us know how things go, we need all the feed back on fixes we can get.

Ade.
91 C4

Wsp964

Hi again guys ...... part II of my stalling/hunting problems....

The probs got worse ..... a fex days ago I was not able to start. It was as I ran out of fuel ... same kinda noise but the gauge was reading 3/4 full and I filled it up 2 days before ....

After some friends pushed the car from parking lvl -2 to -1 the car started once we tried again. Sometimes it did sometimes it didn't or hardly after several attempts.


I managed to get to the garage and let them check everything I came across with on this board concerning my probs.

They checked R41 ... OK, Fuel filters ... OK, fuelpump ... OK, distributor ... OK, fuel gauge ... OK, etc ...

They can't figure out what the problem is sofar ... and apparently once the car enters in the garage everything seems to be OK <img src="graemlins/cussing.gif" border="0" alt="[grrrrrrr]" /> <img src="graemlins/cussing.gif" border="0" alt="[grrrrrrr]" />

Today the car ran fine but I fear the problem is gonna come back as soon as tom !

Think I'm gonna try another mechanic as he didn't really helped me at all ...... the only thing they could say is that it might be an electrical problem not mechanical ...... and we have to see what happens next ...

To be continued <img src="graemlins/crying.gif" border="0" alt="[crying]" /> <img src="graemlins/crying.gif" border="0" alt="[crying]" /> <img src="graemlins/crying.gif" border="0" alt="[crying]" />

WSP964

Wsp964

Another small question :

Can the hesitation be DME related ?

Wsp964

Another small question :

Can the hesitation be DME related ?


Excuse me for my ignorance .....

Thanks.

WSP
<img src="graemlins/icon107.gif" border="0" alt="[icon107]" />

Ade - C4 91

Hi,

By DME do you mean DME relay (Fuel pump relay) or the DME Control System.

DME Relay can cause hesitation and unusual running faults, it's cheap to swap out so I would just do it anyway - if the car has the original 944 part replace with the newer 993 part.

If it cut out completly then might suspect contaminated fuel as Adrian already mentioned. You may have water in there or dirty injectors.

Swap the relay out first then get it down to a Service agent you can trust and get them to Read the DME Fault codes.

Good luck

Ade
91 C4

DaveK

Hi,
Here are a couple of suggestions - although none will be affected by the amount of fuel you have, so may not be the problem.

You say they checked distributors - but what did they check? I had hunting / stalling problems when I bought my car which turned out to be worn distributor caps. Once they were replaced, the problem has never come back.

When you say the car refused to start it reminded me of when my flywheel position sensor died. Engine turned over but would not fire at all - because the position sensor controls delivery of fuel + when to fire. As far as I know, the position sensor either works or doesn't, so probably not your problem - but maybe worth getting checked.

Dave
90 C4

Wsp964

Ok thanks for the input guys ... I ordered a new DME relay and I've found a new mechanic with good references.

It's scary what needs to be checked out .... to be continued I guess .... I'll write asap.

WSP964