95z auto / stock 118k miles (not sig car)

car stalls and won't restart for 30 min. trying to get cable for codes but NO SES light on. heres what has been replaced. OPTI/COIL/PLUGS/ WIRES/BATT/ALTERNATOR. car runs awesome until it fully warms up 190+ degrees car begins to sputter and voltage surges into the red like i just turned on a 3000 watt stereo or something. a huge electrical draw (not cooling fans though) then the car will turn over and try to start but just dies again(batt voltage over 12 volts at this time) (alternator at 14 volts during surge.)....let it sit for 30 min it starts right up and drives for 1 mile or 50 miles?! the next day cold it runs perfect again. some cooler days doesn't happen at all.. all grounds that i can find are good .WHAT IS THE STORY WITH THE ICM OVERHEATING? is it a possibility and how do you test it?

thanks alot guys . just trying to get my bros on the road so they don't go trade them for imports...

 

check the little coolant hose right above the opti....my squuze clamps got weak and once it heated up and built pressure it pissed right on the opti....very hard to see any coolant leak at all.....mine ran just like yours.....when the antifreeze ran out the vent at the bottom of the opti it would restart.

thanks to this my car is in the dealership getting a new opti and just cause the front will be open i'm getting the seals on the front of the motor replaced along with a new cps and tps. gotta love the wallet suck that is the lt1!

 

The ICM is a possibility. Autozone can test them if you remove it.

 

Yeah I 2nd a check on that.

 

scanned it and found during this draw the car goes super lean. so i hooked up the fuel press regulator and it was showing 35 psi (a little low) during normal idle then all of the sudden it drops to 10 psi at the same time the voltage drops to 11.0 volts... this pump has 700 miles on it to boot...my bud says it could be a short in the fuel pump wiring and when the pump gets too hot it shuts down ...what do you guys think???

 

Entirely possible. An overheating pump can shut off, then run again when cool.