Our swap will run for about 15 min then will sputter and die. Runs awesome when cold though. Traced it to a spark issue.

We've replaced just about everything except the MAP and the coil and the car will run great until its around 180*F, sometimes longer. Like one night it drove for 2 hours and hicupped once, the next i got 15 min out it stalled numerous times then started and ran flawless the entire 15 min back home. Fuel pressure is constant and remains so when the car stalls.

Replaced:
MAF
CPS
Control module (twice)
Opti (3 times, once to replace the origional and thought it was miss cause of that, second was installed wrong, third I personally installed and there seem to be no misses or issues.
TPS
Coolant Temp
Knock sensor

Engine:
'96 engine and computer with VATS eliminator module, no AIR, EGR is disconnected, No TCS but nothing is done to the computer.

Car: '92 Camaro RS TBI

One seemingly connected issue: Alternator will charge at 14.5v initially then go down to about 13.9v before the vehicle stalls, yet vehicle will do the same with alternator disconnected (warm) and run fine when cold and alt. disconnected.

Any ideas? I'm stumped and any master mechanics are baffled if I explain the problem as I've apparently done everything they would.

 

Sounds like something going on when it goes into closed loop. Did you have the EGR and AIR programmed out or did you just unplug it, that may be causing some of the problems you're having with it if you just unplugged it and didn't program it out of the PCM.

 

Check the grounds. Also check for a frayed wire somewhere.

Could also be a bad PCM.

 

Have it programmed right. Might want to install a programmed/tuned '95(obdi) LT1 pcm while you are at it.

No codes being thrown? Other things that might be worth checking out are the O2's, they only work in closed loop. '96 and '97 have 4 O2's, '95 only has 2.

 

swapped for OBD1 computer with emmisions crap out of it and it does the same thing, tested the connector to the control module and it seems as if the opti is gone again, what confuses me is why its acting like a control module problem. Putting a genuine AC Delco part in but so help me god if this doesnt work, I dunno what to do.