What could cause this?
#16
Racer
Thread Starter
New fuel pump and filter. Rail FP with-in spec. No vacuum leaks I can find. Good 3 Bar FPR. Tank strainer looks like new/very clean. Calibrated WB w/new O2. Problem still exists. Cold start fires right up solid idle AFR cold 14's as it warms AFR keep creeping up17-18's then the usual idle falls and stumbles no change with throttle in-put it actually makes it worse and stalls, again this all happens with-in 5 minutes from start-up! Heat related? It barely runs long enough to get hot. Restart won't idle barely runs. I do have original stock injectors, if one/ multiple were bad would it cold idle fine at all and then act up? Intake manifold leak? AFM?
Again car was 100% with slight exhaust manifold leak. Headers installed with considerable idling after install, which I've found to be unnecessary. Could excessive engine bay heat have anything to do with my issue???
UGH!
Again car was 100% with slight exhaust manifold leak. Headers installed with considerable idling after install, which I've found to be unnecessary. Could excessive engine bay heat have anything to do with my issue???
UGH!
#17
Racer
Thread Starter
Issue getting worse. Now on cold start barely idles and then stalls. Did another smoke test nothing, only a whiff from the spring on the side of the throttle body. I'm told that is very typical, otherwise no small vacuum leaks no large vacuum leaks.If you've read my previous posts on what I've done to this point any other suggestions would be appreciated. My "Mechanic" HA! still thinks it the Idle Control Valve being stuck. Before I pull the manifold again to access it (2 yrs old OEM Porsche) and the fact that I've had no idle issues or for that matter any issues until New Headers installed, yes I know it's not the headers. So, for the last time, Can my issues be ICV related??? AFM Bad??? Other???
#18
Intermediate
You can always test the ICV using a 9v battery without removing it. Put the positive on the middle contact and alternate the ground wire to touch the right or left contact. This should make a clicking sound telling you it's still good. You could unplug it and see if that changes anything.
I would try what Tom suggested and unplug the O2 sensor screwed in the crossover pipe so the DME runs in a loop mode and see if that does anything. Do you know if the shop took the intake manifold off to get to the crossover pipe? The injectors could be an issue, but also if the shop took the manifold off they would of had to remove the fuel rail. Perhaps the injector wiring isn't connected properly or something. Clarks garage has a testing procedure for the AFM.
I would try what Tom suggested and unplug the O2 sensor screwed in the crossover pipe so the DME runs in a loop mode and see if that does anything. Do you know if the shop took the intake manifold off to get to the crossover pipe? The injectors could be an issue, but also if the shop took the manifold off they would of had to remove the fuel rail. Perhaps the injector wiring isn't connected properly or something. Clarks garage has a testing procedure for the AFM.
#19
Thom up above may be on the right track here suggesting the shop damaged something. When motor mounts are changed up it is not uncommon for people to raise the engine up a bit with a floor jack underneath the oil pan. I would wonder if they over- jacked the engine and brought the engine into contact with other parts of the engine bay or stretched a wire to pull it out of a socket or connector. Or popped a hose free along the firewall. Or damaged a harness somewhere by pinching or cracking it. Hmmm.
#20
Racer
Thread Starter
Just Fedex( $22 w/$700 insurance) my DME & KLR to 944online for testing. I've had it replacing things with no changes. Ian will test at no cost. I Actually hope one or both tests bad. If not, the saga will continue.