Fast944T

Hello rennlist - We have a 87 model, we did the search button but I think we need more help. When he drives the car, he lets off the gas and the car jerks forward a little and the engine kind of engine brakes - i know the engine is going to do that, but this seems extreme to me. The rpm goes from 3,000RPM - he shifts - and drops instantly to 1k rpm. I set his idle at 1,000 - maybe that is high, it just sounds right to my ears

maybe i am just not used to these german cars.

dillon410021

My car will nose dive in 1st gear when I let off the gas

Fast944T

I drove the car yesterday to figure it out. Jerks and engine brakes hard when I let off the gas in every gear at any rpm at any speed. I cant figure it out for the life of me

Now that I am thinking - should I be adjustin the throttle postion via the screw-post and nut on the throttle body? Maybe open the throttle a little and adjust the throttle switch accordingly

The car has a entire new throttle body I am thinkin the owner just slapped it on and called it good enough without tuning it

gt37vgt

I think the solution is to drive it like you stole it drive faster brake later and you won't notice the problem

dillon410021

haha

Fast944T

I assume this is the way a Porsche is designed to run from the responces. okay then, thanks.

ryanm6100

Could it be a faulty bypass valve? When the TB slams shut the BPV doesn't let the air out causing compressor surge, thus jerking or bucking?

Total speculation here, but may want to test the BPV just for ****s anyways.

333pg333

If you can shoot some in car video and post it on YouTube to show us...

Fast944T

When I put in the clutch, the RPMs drop right to 1k rpm. thats no problem right? when I am in gear driving his car, say 50 mph in 5th gear at 1.8RPM... I let off the gas without touching the clutch the car sounds and feels like it's Engine breaking. I will try to get a video up.


I have this feeling that the throttle position is off. I willl try to fix it and if I fail, I will have him work the camera in the car

gt37vgt

i had a bad tps the closed switch was crook it would shut the injectors down above 2000 as it would still be seeing a throttle closed signal and when it dropped to 1000 it would recover.

VOoDOoGTX

this happened on my audi. Engine mounts failed.

ehall

Could be the TPS, could have something weird happening to the diverter valve. Is it a stack diverter valve? You could also have a significant fuel issue. Has the fuel filter beeb replaced? How are the injectors?

Fast944T

I adjusted the screw on the throttle body about 2 twists... and she is working amazing!