Originally posted by eclipse982nrRST
I kind of have this issue too. The car will sit and idle for awhile, but then randomly, if I give it gas, the idle will hang up around 2800 to 3500 and stay. Looked for vac leaks too and found nothing. I havent dug deep into this problem yet though because I am working the body over on it again, but my fans wouldnt turn on either, so I am thinking I might have a junk ECU as well. But everything else works fine, I have no troubles getting it started and have power to everything else I believe. Interesting.

the problem seems to be intermittent. Once i wired in a voltage regulator, blocked off the IAC, wired in relays and a switch for the fans and fuel pump ... the stock tach decided to start working, I assume that it was performing all its other duties as well. Well as the car sits right now the MS is basically a full standalone minus the factory ecu supplying a power source to the sensors. I ran a 0 guage wire from the back of the block to the rear of the car where the MS is grounded along with the battery, relays and wideband. SO FAR this seems to have taken care of the tach spike issue! I am very excited and am learning a lot about tuning cold starts lol! All the bullshit aside I am very happy with MS. Thanks for all the input guys!