gcpa968

Hi guys,

Having a problem with the 993tt at the moment. I had a fuel pump failure and a new fuel pump fitted last Wednesday. Took the car out for a spin this weekend and on hitting full throttle the car stuttered really badly, so I returned to base and left the car, returning later. This time the starter turned over but the engine would not start. I replaced the DME relay and the car started. I took the car for another spin and on full throttle runs the car continued to stutter quite badly. I suspect the fuel pump is the problem but would appreciate your input. Having read recent threads it sounds as though the MAF sensor could be at fault?

Any thoughts?

Thanks in advance.
G

Felix

When was the fuel filter last changed? What where the symptoms that led to the pump being replaced? The new pump can be tested quite easily; it needs to flow some minimum volume of fuel in 30 seconds to be deemed "good". I would suggest getting someone with the right diagnostic skills and equipment to look at it otherwise you might throw some expensive parts at the car before the problem's solved.

gcpa968

I had a minor service earlier this year (June) when the filter would have been replaced. The failure symptoms were a brief stuttering and then the car broke down completely. Unfortunately I was hundreds of miles from the nearest porsche mechanic and I took it to a local mechanic who held on to it for a month before admitting he couldn't fix it. It was then trailered down here to a specialist who diagnosed the fuel pump being at fault. Not sure whether I should continue driving the car around to try and "clear" the problem? My mechanic is back tomorrow and I'll give him a call. Its very disappointing as I haven't had a chance to drive the car "properly" in a couple of months now.

dbf73

I woould confirm that the filter was changed. If not, that's the first place to look

911/Q45

I wouldn't drive the car, very few problems "heal" with use. I think the problem was the MAF all along. They are very tricky to diagnose.

gcpa968

Thanks guys, I wondered about the MAF as the roadside revovery guy tried putting fuel into the engine through the air intake and I understand that this can damage the MAF. Unfortunately my mechanical knowledge is slim to nil and I didn't advise him against that course of action.

G

Felix

That sort of thing went out with carbs in the 80s!!! Having said that it probably didn't damage the MAF but it's hardly good for the cats.

johnneurauter

dumb question, but have you checked to see if your intercooler is bolted down solidly and that the hoses feeding it are attached properly and not frayed at the ends? i know that'll make the car stutter.

gcpa968

I'll check that tonight if I get the chance. The car is booked to go into the local 993 specialist at the weekend so hopefully I'll get this sorted soon. There is still some good driving to be had before the winter properly sets in.
Thanks.
G

ACEparts_com

And the outcome was.... Sorry to bump this up but it sounds like my car at the moment!