First of all, any help would be appreciated! I bought a 95Z some months back with around 135K. Two days later it started severely overheating. To try and make a long story short there was water in the some cylinders and a blown headgasket. Proceeded to tear down the top half and start refreshing. At this time I installed headers and true duals. I got the heads resurfaced and new seals new gaskets, new delco plugs, wires, water pump, and hoses, new cap and rotor, new coil, and a rebuilt distributor (money was tight). I also deleted the air and egr. After all that the car ran good for about a week and then came my new problem, the car started missing badly and running very rich. I just replaced the 2 oxygen sensors and at first car wouldn't crank. Tried a second time and it cranked revved up to about 2K then idled down to about 800 where it was very erratic. It started sounding like it was about to go dead so I shut it off. Now car won't crank at all???

 

Sound like your rebuilt Opit just died! Where did ya get it at? I would try and take it back and get a GM one..

 

The car on a stock motor will run like crap without the egr. Look at the coil and coil wire also.

 

I removed my egr on a basically stock car and it still runs fine. No problems at all. When you say it won't crank do you mean it doesn't do anything, or the car cranks, but doesn't fire?

 

It will turn over, just not start. When it had the original o2's before the swap and it was missing and running rich, the car would run fine until it reached operating temp then would start missing. Also after it would start missing while driving sometimes it would just go away and run fine for a while then start back missing?? So I replaced the o2's and now she won't start!

 

Doesn't seem like an O2 problem. The car runs in open loop until it's warmed up anyway. Sounds like you crossed some wires, have loose wires, or a bad opti. Check all your fuses.

Dan

 

I agree with Dan, O2's should not cause a starting problem...

 

I had a similar problem with my 94 a couple of weeks ago.turned out to be the coil wire.Had the same symptoms/engine revving high/erratic idle/it also set a trouble code and turned the fans on.I replaced the coil and plug wires and it's been fine since.