Re: 8 cams are better than four!
 

not always. I have a vac leak somewhere now and my idle is fine

Re: 8 cams are better than four!
 

Sorry your having issues, but sometimes happens when a car sits for many years. here is a link to replacing it.

http://zr1.net/forum/showthread.php?t=14475

Re: 8 cams are better than four!
 

Got the window regulator out. Looking it over its clear water got in there at some point. I'm going to bite the bullet and order a new one rather than try to just replace the motor. At this point wife's eyes are just rolling. :)

Also had time to pull the air horn and get ready to pull the belt. Headed out of town now so the car will have to wait until Sunday.

Re: 8 cams are better than four!
 

And fwiw while I was listening to the pulleys and determining that it was indeed the water pump, the idle was perfect. Go figure. This was with the accordion removed but the air horn still in place.

Re: 8 cams are better than four!
 

Mark,

Check the numbers on the prom, the 90's had a change to fix idle issues. Marc's site lists them.

" The performance calibration AYBKG is based on GM's latest release of the calibration for '90 LT5 engines. GM calibration AYBK was released as a service part via Product Service Bulletin 476503, dated February, 1994. It was released to address problems with idle fluctuation after a hot restart, increase in idle speed after a hot restart and excessive engine speed during coast down to a stop with the clutch disengaged."

http://zr1specialist.com/HAT%20Web/p...librations.pdf

Re: 8 cams are better than four!
 

Great info and considering how this car sat for so long, I'll bet its original. Come to think of it, the engine was warm when the idle was so high. This afternoon was a cold start and the idle was perfect. Maybe I'll buy more from Marc than I planned...

Re: 8 cams are better than four!
 

When my evap purge line vac source had popped off the plenum, it would idle at 900 rpm cold, but creep up to 1400 or ?? whatever when it warmed up. These cars do tend to run on with a high idle until the car almost reaches a stop, but parked, it should be able to idle at 700 rpm.

I would still do the stiff binder book in front of the air horn to see if the engine stalls out or not. You will hear he leak if it can still manage 600 rpm with the intake blocked

Re: 8 cams are better than four!
 

What are your symptoms? Have you ruled anything out?

Mine is killing me right now here - idling fine too, and I MIGHT have a vac leak, but can't figure it just yet here... It starts the 'lope' just ABOVE idle... (in the Hesitation diags thread, that GC changed for me there)

Sorry to boost your thread here 4cam...

Re: 8 cams are better than four!
 

Re: 8 cams are better than four!
 

Take that window motor apart and see if you can clean the magnito and the magnets, hookit up to a battery and see if it works.

Sometimes they get water in them I have fixed some in the past without replacing them.

The rust is just enough not to let it turn.