Re: Plenum Pull...Parts List Varification...
 

[QUOTE=| 1990 ZR-1 |So a word of caution, do not stick a large pin into the ECM connector when measuring the injector resistance. Otherwise you?re taking a chance of loosening the connections.[/QUOTE]

One of the veteran members here did this and took awhile to find the problem.As far as the tires breaking loose at 35 MPH,thats some scary $hit aint it!375 HP doesnt sound like alot in todays HP but its enough to put you into a tree in nothing flat.Its not hard to undersatnd why today people are still wading these cars up.When I first got my car years ago it had the the original tires that were as hard as hockey pucks.I think I got the tires to break loose going 50 one time.It was fun at first but got old real fast.Good to hear the cars back together.:thumbsup:

Re: Plenum Pull...Parts List Varification...
 

When I got my 91 last January, it still had 14 year old GSC's on the back and the inside was corded. found out the ABS still worked fine, and yes, it blew the tires as soon as the engine reached 4000 rpm pretty much everytime.

Re: Plenum Pull...Parts List Varification...
 

:saluting: to you Gary for a job well dunn!


See, these cars are very entertaining!:mrgreen:

Re: Plenum Pull...Parts List Varification...
 

Thanks Tom. That was me calling on Friday for a brief moment before I lost signal. I couldn't get her started, and after double checking everything, couldn't figure out what the issue was. I traced my steps back and realized that forgot to connect the two connectors on the underside of the plenum. No matter what I tried to get them plugged in without removing the plenum, didn't work. So I had to remove the plenum again. It only took 15 minutes though.

I do have another question for you. My car idles around 900-1100 rpm, and idles even higher when coasting to a stop in neutral. Through some research I noticed that Mark Haibeck sells a tune that should cure all those symptoms along with some other improvements. I also found a post by you stating that you have that tune. Are you still happy with it? Anything I should watch out for?

Re: Plenum Pull...Parts List Varification...
 

Hi Gary,

Jez I'm sorry that the signal went belly up! Yes I have that tune and thus far it is the best money that I have spent on any performance part for my car.....actually it's the only performance part my car has!

Everything that you are describing is typical of the 1990 EPROM with the AUAH programing which GM replaced with the AYBK program in a TSB as an answer to the complaints from owners. It was a big improvement over the AUAH EPROM.

I should say that I'm even more satisfied as I bought an AYBK EPROM from GM when they were still in stock and it corrected the idling issues and the coast down issues, but Marc's tweeks to the AUAH programing include eariler fan "on" temps to yield an operating temp closer to 200*F vs the GM 220*F programing. Marc also cleans up the fuel map so it is more effective at part & cruise throttle settings. Overall it's the best money I've spent on the car besides tires & gas! I highly advise any 90 owner to get Marc's chip!:worship:

:cheers:
Tom