94 3000gt idle messed up after spark plug change
So I bought a 3000gt, did spark plugs, put back together,
now I have an extremely rough idle and I cant get the base
drive speed and idle to match, I got the idle set to 1000,
but whe I put in drive the rpm just falls to about 200, my
buddy messed with the biss? The one on top of the
throttle body, the throttle cable etc, cant get it right, so
now I feel all sorts of confused, car ran rough when I got it,
so I thought plugs, and they were fouled, and now I'm
running rich also... when i opened the plenum, one of the 6
was nice and silver the rest were black. Um I'm at a loss
Did you mix up plug wires?
Negative, also just noticed, in reverse or drive it maxes out at 1500rpm
But in park or neutral I can rev the hell out of it
Start idle
In gear
In gear floored
Rough idle comes from vacuum leaks and or MAF TBS IAC issue related. Never adjust the biss screw unless tou know what tour doing. You need to go 3si website login as a memeber and download the manual and follow factory specs on that biss screw. By adjusting that it messes up the ECU calculated measurements and will cause other electronic to start failing. So now you messed with it. Unscrew it out completely and see if the rubber O ring isn't cracked or broken. Can replace it at your local napa store. I had the same issues on my 91. Did the routine spark plug wire and had high idle at cold. The ECU needs to be reset. I was told to tifhten the biss screw in all the way and 2 .5 turns out and drive it till the ecu relearns. Idk but it worked on mine. But i had to replace the PTU IAC and TPS aswell. Also too. I hope you replaced the gasket on intake. Never reuse old one lol. Thats how vacuume leaks occur. Check all your vacuume hose too. And to make sure did you put all spark plug wires back in correct order
