Help! Car won't idle anymore

[Nick_S]

OK, doesn't appear to be timing. We did a compression test and to my relief, 180+/- across the board. Plugs indicate the car is running VERY rich as is. Hooked up his code reader and it popped up a code for MAF. Swapped in another I had and it runs marginally better but still stalls while surging and hunting for idle. Unplugged/replugged and checked every sensor we could. Pulled the injectors and fired it and they all spray well. Sprayed all over for vac leaks and still, even with a real mechanic, couldn't find any sort of smoking gun (truth be told it made me feel better he couldn't find anything, haha). It's acting like it has a huge vacuum leak but can't detect one. I then thought maybe it was sucking air from the crank case as if it had a large leak so we plugged the crankcase vent to the intake tube and that didn't change anything.



At this point I called my buddy back in Ohio who's shop I did the swap initially and got his log in for identifix which if you're not familiar is a shop use resource where people can log issues they've had with the associated fix. Lots of similar cases and almost all signs seem to point to a faulty ICV or bad Crank Sensor. Going to OHM those out tomorrow and go from there.

[e30austin]

If you some how mis-orientated your ICV (put it on backwards), I could see that happening. A good, quality CPS would be a good place to start, at this point.

[Nick_S]

Still fucking with this thing...so, since my last post I have tried a known working ICV with very little change. It will idle longer but is still misfiring slightly and will eventually die. I tried swapping coils this evening as well with zero change across the board. Ordering a new OEM crank sensor this evening and going from there. If I can't figure this out soon then the only tangible option of course is to track down a good running S50.

[Nick_S]

New CPS somehow made things worse. Car won't even start now. ugh, wish I had left the engine in the car when I did the trans work.

[Nick_S]

Holy fuck I'm an idiot. Borderline embarrassed to type this. I somehow installed the crank pulley on wrong. Despite it having a guide pin, I had it off by a bolt hole. I have no idea how I did this, I must have had it on, bumped it off and when I put it back on, put it on a hole off and tightened it down pushing the guide pin out. Re-oriented it last night and it fires up immediately and idles perfect. Good god I feel like an idiot. I had thought about this but couldn't imagine how I would have messed up such an easy step considering the actual hard work was all done correctly. Oh well, happy to have that sorted.

[IceWhite]

How did you figure out your mistake?

[Nick_S]

How did you figure out your mistake?

Laying under the car scratching my head as I've done for the last couple weeks. I've checked every conceivable thing I could think, double checked every connection, smoke tested it, compression/leak down test, OBD1 scanner, swapped parts....and was looking at the timing marks on the trigger/crank pulley and noticed the pin sticking out the back. Took it off, sure enough I had messed up what should have been the most brainless part. Trying not to beat myself up too much over but holy hell what a stupid mistake.