Well it finally happened. The old 1994 Z-28 started up yesterday but with an unusual hesitation. Half way down the driveway it stalled and couldn't get it started, it cranked real good but no fire. I pulled the MAS wires and waited a bit and it finally started, ran for 10 sec. and died. Today I cleaaned the MAF sensor with the 12 dollar can of cleaner. Fired right up and ran for 45 sec. and died. So.........I'm thinking maybe two things. Bad fuel pump or the much hated Optispark everyone talks about. Is there ANY quick back yard checks I could do ? Really dont want to take it down to the local rip off garage if I don't have to. Is there a source for an old Tech tester. ?? Thanks.

 

My old '93 Z acted like that when the Opti was failing.

 

OK Thanks... Did you change the Opti yourself ? How hard is it ?

 

No I had it done in a shop.

 

I'd start with checking the fuel pressure, its easy and a gage is cheap, the schader valve is on the fuel rail at the back of the engine near the fuel pres reg, spec says 41-47 psi but can be lower at idle, recall mine being 33 at idle

 

Thanks did that Checked out OK.. 41 at high rev, 37 constant. I did someone to talk to me about replacing the "Opti" Thanks

 

look at 28 here 4th Gen LT1 F-Body Tech Aids bad opti can throw a code. usually but not always. lol.

 

Thanks Read it, sounds complicated