Hi guys, I have a unsolvable stall problem... Engine on idle works perfect, revs up, goes also good but... after pressing clutch or changing gears cars stalls.. After rev idle drops below 800 rpm and jumps over 1000rpm and then back to normal idle...

Car just imported from Canada to Europe and I have no idea what to do more :

1. Idle control valve ( cleaned - working )
2. Flow meter checked
3. Vacum seams ok
4. DME relay changed ( no difference )
5. Caps, rotors ok
6. Idle switch checked

What I found in car :

1. Evolution motorsport air filter
2. Weltmeister chip

Sorry for the spelling errors. Do you have any thoughts?

 

Run Idle Adaption with 'Hammer' or Scantool.
Another option is to disconnect battery for at least 30minutes. This will result in a complete reset of your motronic settings.
Due to the fact you checked most of the common problems my guess is this will solve your problem.

 

Power disconnection also tested, no improvement..

 

Do a throttle adaption using the Porsche factory scan tool (Hammer). I would also replace the Weltmeister chip with either 911Chips (Steve Wong) or one of ours.

Make sure there are NO vacuum leaks by smoke-testing the intake system.

Replace the oxygen sensor if it has more than 40K on it.

 

Before replacing parts or focus on other tests tried to disconnect one coil pack and start the car... Disconnected second coil pack ( from rear of the car ) no engine work change, than connected and disconnected first ( from the rear of car ) engine not working on all cylinders.

If I understand well lower spark plugs not working fine?

Can it cause engine stall? I guess I should start with the plugs... By the way car has 47k miles on clock

Thanks for advise.

 

My car had a bad coil but the car still idled and ran, just not with full power. Have you checked the distributor belt?

 

ok.. no progress

1. New spark plugs...
2. distributor belt like new

Maybe lightweight flywheel? Still looking for adaptation tools

 

The lightweight flywheel issue is that the standard ecu can't react quickly enough to stabilize the revs when decelerating to a stop. In other words you come to a stop with the clutch in and the engine stalls because it doesn't react quickly enough to the idle situation.

I have a LWF and an aftermarket ECU that is rock solid.

 

Could you please explain the issue with more detail?

Does the car run on idle with no issues? Btw Rev fluctuations at idle at least while it settles down are normal. It's a feedback loop where the car is adjusting to run at the set revs.

Does the car run above idle? If so what exactly is it doing?

Btw a local car had issues with its engine and it turned out to be a bad cylinder head temp sensor. If you had the scan tool you could check those and other readings, plus do the adaptation.

 

Engine on idle works perfect, revs up, goes also good but... when taking car for a ride after pressing clutch or changing gears cars stalls.. idle drops below normal and engine stall.. after restart idle jumping from 800 to 1100(1200) rpm and gets back to normal idle.

Also checked with stock air filter and stock engine computer...

Engine can't catch idle when driving, jumping up and down and goes to zero and the engine stalls. Car was at local Porsche dealer. They have no idea what to do.. No engine malfunction.

 

For example. Can you put the car into first gear and accelerate ok? Does the car then stall the moment you put the clutch in to change to 2nd gear? If so, does that happen at any level of revs?

 

First gear and car goes with no issues, changing gear depressing clutch idle drops below normal idle rpm jumps up gear changed going up, traffic light - clutch - stall, start up 1 gear ok, 2nd ok, more power, road turn, clutch and stall. If changing gears at higher rpm engine stall more frequent. When rmp dropping from higher level seems like ICV can't "catch" them...

 

No wonder the Porsche shop is confused, as I can't make sense of it either.

If I understand it correctly, the car idles and accelerates normally, however the action of depressing the clutch leads to a rapid reduction in revs and the car stalls, even from higher revs.

Unless you are running an incredibly light flywheel I can't think of a reason why revs would fall so quickly. The stalling may be a symptom of a light flywheel not a cause. Do you know what flywheel is installed?

 

Sounds like LWF and no chip. I would borrow a good coil and try that first. The new silver Bosch coils are kinds ****ty. I went through a few sets before I got good ones. I wrote plenty on here about my issues about 4 years ago. Also, no shock the dealership has no clue. Most of the air cooled techs are long gone and the kids who are part replacers don't know these cars. In my experience there are a few guys at dealerships that know these cars, but it's a dying breed.

 

Throw my two cents in for what it's worth. How is your battery? I don't mean holding a charge, but age and quality wise. I had a stalling problem when rpm's dropped with the clutch pressed coming to a stop. I found an old thread that recommended a new battery. I thought it was a crazy idea but purchased a new optima yellow top D35. Car has not stalled since I put the new battery in over a year ago. We can let the conspiracy theorists try to explain it, all I know is that it worked immediately. Maybe disconnecting the battery and re learn the map was all it needed. Someone else says bad batteries play tricks on these cars. But a new battery worked for me and a few others with stalling problems.