Bondo07

I have a 92 z24 with a 3.1 that used to be an automatic until the previous owner swapped it out with an 89 5 speed. So now my speedometer has never worked, and no backup lights. No big deal for me. but When downshifting to slow down, the check engine light comes on and stays on till i shut the car off. Also while sitting at idle, after about 20 seconds the idle increases slightly and check engine light comes on again. I swapped out the idle control sensor thinkin maybe that was it, nope. Even worse is after driving for a while, the check engine light comes on again and the engine runs real rough. push the clutch in and it drops to about 500 rpm or less and bounces up and down till it dies, i shut it off, or i hit the gas, but continues when i let off. The only idea i have is that the computer still thinks its an automatic and encounters some weird glitches. I don't have another computer to put in and really dont feel like spending that much. also the plug that origionally fits in the automatic obviously does not have a place on the manual. could cause problems but i'm not sure. Any ideas? Other than electrical issues the only problem is the cv shafts, clutch, etc all have to be ordered for an 89, not the 92.

MDTAHOE

What code is the computer putting out when the check engine light is on?

Bondo07

2 codes. ignition control valve... i think that's it... and A.C. pressure, but that's no biggie. I took out most of the ac plumming. Doubt that would have anything at all to do it. maybe my muffler fuse blew and shorted out my fan belt computer. lol