Problem- Almost completely solved.

**ABSGTP** · 12-10-2012

2000 GTP original motor spun bearing, replaced with a "recycled" motor. That motor was about to spin bearing and showed 12-15 hg vac at idle.
Got another "recycled" motor just put it in and plugged in. Started and ran fine, after getting on the hwy it started to have a fit bucking, stumbling, and wouldn't stay running even in neutral at traffic lights.
I checked/cleaned every ground(under hood), cleaned the positive connections, took apart and cleaned ICM and coils.- Also cleaned up the bracket on which the coil pack sits. Replaced battery bolts, both the alt, bat, and starter were checked and tested fine. I started it up and ran/idled perfect showing 17-20Hg vacuum. I let it sit idling while I picked up tools(5 min) drove away and within a mile it starts having a fit again which got worse as motor got warm. Once cooled down I switched out ICM and coils and barely started ran rough and showed about 12-15Hg of vac again!!!
No SES lights but bat and oil.
Oil level is fine.
All vac lines are perfect.
I am lost!! Any ideas?? I have searched the forum and haven't found the same symptoms has I have... Feel free to PM me.

**Scottydoggs** · 12-10-2012

the check engine light on?

if so go get the car scanned. they will give you the codes. aotozone does a free scan.

**ABSGTP** · 12-10-2012

no codes, scanmaster on dash, scanned before and there was nothing not even in the history.

**dsmuts** · 12-10-2012

Having low vacuum readings doesn't mean it's about to spin a bearing. You might have a vacuum leak

**BillBoost37** · 12-11-2012

How's the KR?
Getting misfires?, which cylinders?

**ABSGTP** · 12-11-2012

when the current motor(which doesnt have a knock- as the last two did) has no knock/codes when it was having a fit. Last night I eliminated the FP resistor by bending the relay prong. I cleaned the MAF(correctly), ran it unplugged, problem still there. A buddy of mine is checking wiring today(working double), also have the orig ecm. I have a wix ffv fuel filter haven't installed that due to the crusty line. Other than the knock(that engine 2 had) this is the same thing engine #2 was doing.. which leads me to MAF, wiring, or ECM those are the only things that haven't changed. I find it hard to believe that the crank or cam sensor bad on both.

**BillBoost37** · 12-11-2012

I see where you are coming from. I'd take it out and scan it to see what is happening when it's having the fits.

If it goes super lean or rich, maf drops out/acts goofy, misfires etc. I've seen misfires w/o codes etc. It seems that you have a scantool on hand and it could make the diagnosis much easier.

Hint: if you think it's a crank sensor....check runtime counter. If it resets at any point where you didn't turn the key off... toss one one there. Cam sensor shouldn't cause this issue at all.

**ABSGTP** · 12-11-2012

Thanks Bill we will see how it goes....

**ABSGTP** · 12-13-2012

OK I wont name any names so I will just say ME....didn't loom the crank, cam, icm harness jumper correctly and it rubbed against the WP pulley. Fixed the wiring, loomed it correctly and runs great. Still have 10hg vac at idle, will change the IAC valve and see what happens.