Hey guys first timer here, love the site! recently bought 86 Iroc and here are my problems:

I have an 86 Irocz 305tpi, car starts fine, fires right up, i recently removed A.I.R pump, I know no biggy. But the car runs for a couple minutes then surges, I can drive it but it falls on its face a little, I can punch it and it kick down and goes nicely. also there is a little bit of a spit comming out of the exhaust, a spit sound like a miss. My single fan doesn't kick on like it should, replaced the fan relay but never changed anything. could the ECM be the cause? Also temp gauge is functional sometimes, feul gauge bounches. I'm sorry I'm rambling on, but not as technical as you guys. Love the car just want it to work properly! any suggestions would be awesome thanks

Dustin

 

It sounds like you may have more than one issue. It may be a ignition miss , low compression injectors or even a leaking fuel pressure regulator. You should start out checking your fuel pressure and ohm your injectors when the engine is warmed up. You can check for a ruptured diaphragm by pulling the vacuum hose to the fuel pressure regulator and look for signs of fuel. A visual inspection of the cap and rotor and ohming the ignition wires to narrow it down to a cylinder or doing a cylinder drop test. Signs of a bad ecm are running rich, the check engine light on and no communication in field service mode or with a scanner . You should diagnose the fan as another issue although this could be a ground issue behind your drivers side cylinder head. When jumping the aldl a to b with the key on the ecm grounds the green/white wire at C1 to command the fan. You will have fuse power on the blue wire on the coil side of the relay. The power going through the relay on the red wire comes from the starter and goes to the fan on the pink/blk wire.

 

Thank you Tuned! I'll get right on it and keep you posted!