GMC Suburban stalling puzzle

My wife's car, A 1993 GMC Suburban 1500 with Automatic transmission, fuel injection, ABS brakes, Dual A/C, PS, and cruise control has developed a difficult problem.
The car has about 93,000 miles on it.

In the morning the car starts fine and runs well for about 5 minutes. Then as the temperature gauge needle comes off the peg the car starts backfiring and stalling until after the thermostat opens and the temperature reaches normal operating temperature. Just below the 210 degree mark on the gauge. Once the car is fully warmed up it runs well for the rest of the day even if it's not running for a couple of hours. It does this every day.

The fuel filter was dirty so it was replaced.
Dry gas and fuel injector cleaner was used for the next 3 fillups.
The fuel pump was replaced. Had to drop the tank.
The thermostat was replaced and the fuel regulator disassembled and cleaned.
The ignition wires were replaced.

None of this has fixed the problem. The mechanic is puzzled and has no idea what could be wrong.

Does anyone have an idea of what to look at next?

Regards,

Dominick

My wife's car, A 1993 GMC Suburban 1500 with Automatic transmission, fuel injection, ABS brakes, Dual A/C, PS, and cruise control has developed a difficult problem.
The car has about 93,000 miles on it.

In the morning the car starts fine and runs well for about 5 minutes. Then as the temperature gauge needle comes off the peg the car starts backfiring and stalling until after the thermostat opens and the temperature reaches normal operating temperature. Just below the 210 degree mark on the gauge. Once the car is fully warmed up it runs well for the rest of the day even if it's not running for a couple of hours. It does this every day.

The fuel filter was dirty so it was replaced.
Dry gas and fuel injector cleaner was used for the next 3 fillups.
The fuel pump was replaced. Had to drop the tank.
The thermostat was replaced and the fuel regulator disassembled and cleaned.
The ignition wires were replaced.

None of this has fixed the problem. The mechanic is puzzled and has no idea what could be wrong.

Does anyone have an idea of what to look at next?

Regards,

Dominick


I would look at the distibutor pick-up coil, may be getting weak

If the pick-up coil doesn't solve the problem,then I would check the temperature sending unit for the vehicle computer.You may need to take the vehicle to a shop to plug into the vehicle computer and monitor the engine temperature rise as the computer sees it.
chuck's