turbowop
Well-known member
So ever since I got home from a DSM/Evo meet I went to in June with 1051, the car has had an idle surge issue. I'm just now getting to diagnose it. I tested the ISC and it tested out fine, but swapped it with the one in 503 anyway and that's not the problem. Car has a blocked off FIAV and EGR. BISS is set correctly as well.
So I boost leak tested it. At about 10psi, the throttle body shaft seal on the TPS side starts leaking a steady stream of air. I could feel it coming out from under the TPS, so I removed it and the shaft seal is definitely the problem. Would this leak/suck enough air at idle to cause a surge issue? Since the shaft seal is technically between sides of the throttle plate, I wasn't sure if enough air could get sucked through it during vacuum to cause surge. I have a couple of seals here I purchased years ago that I could install, but figured I'd ask anyway. Pulling the TB apart to replace these looks like a pain in the ass. /ubbthreads/images/graemlins/crazy.gif
So I boost leak tested it. At about 10psi, the throttle body shaft seal on the TPS side starts leaking a steady stream of air. I could feel it coming out from under the TPS, so I removed it and the shaft seal is definitely the problem. Would this leak/suck enough air at idle to cause a surge issue? Since the shaft seal is technically between sides of the throttle plate, I wasn't sure if enough air could get sucked through it during vacuum to cause surge. I have a couple of seals here I purchased years ago that I could install, but figured I'd ask anyway. Pulling the TB apart to replace these looks like a pain in the ass. /ubbthreads/images/graemlins/crazy.gif