problem keeping 2001 Lanos running

[OutlawWolf]

Desperately seeking solution. I have a 2001 Daewoo Sport, 1.6 DOHC, Manual trans, 71k miles. Everything is stock. When I purchased the car it had a broken T-belt tensioner, which took out all of the valves. The Mileage was only 62k then. I replaced the head with a new one, new tensioner, idler, T-belt and water pump. After doing all of this I realized that the temp sensor was bad and the fans ran all the time but I didn’t have the time to fix it, other than that it ran fine. 3 months later during the winter the car developed a flooding issue. Thinking that it was caused by the temp sensor, I changed them both. The fans no longer remained on and the check eng light went out and was no longer flooding. However as the engine started to warm up less than a quarter of the gauge the car began to misfire and stall and would not restart until it cooled down. Checked spark, fuel, wires, plugs. Checked timing and water pump and thermostat. The system is NOT losing any coolant. The only code was multiple misfires. Changed ECM and still the same issue. As it stands I can only drive about 20 minutes or less when it is cold as soon as it starts warming up it starts missing, backfiring and stalls. I even tried wiring the fans direct but it still does the same thing. Any ideas?

[benzino]

crank sensor?

[OutlawWolf]

The thought had crossed my mind and I have a spare I will try it over the weekend. I have never known a crank sensor to be intermittent, they either work or not and how would that be heat related? The injectors shut down everytime just as the temp gauge starts to move about 1/8 of the gauge and won't even try to start until it cools down for at least a half hour or so.

It's a place I haven't checked so it is a good place to check thanks

[PrecisionBoost]

My first guesses would be

1) Fuel filter
2) Fuel pressure regulator
3) Fuel pump

Quite often a fuel filter can give this type of intermittant issue, it may seem more like it's related to heat, but it's possible that in fact it's related to operating time instead.

Fuel pressure regulators usually work or not, but who knows, it's basicly a piece of plastic in a metal can connected to the fuel rail ( which gets warm )

Lastly it could be a fuel pump, the pump may work for a period of time, start to slow down and eventually stop until the electric motor has time to cool down

Your ECU will not be able to detect fuel pressure problems, my suggestion is for you to measure the pressure when you first start up, drive it until it starts to stall out and check the pressure again.

A drop in pressure will be related to one or more of the above issues I mentioned.

[OutlawWolf]

One of the first things that I did was replace the fuel filter and it needed it, but that wasn't the problem. I also put a fuel pressure gauge on it and the pressure was fine both before as well as after it die's and won't start. At this point I am fairly certaint that it is electrical issue because it appears that the injectors just shut down. If it were the pressure regulator failing it would be dumping fuel back to tank and there would be no pressure, I would think. Anyway thanks for your suggestion, this is driving me nuts and it is my only car.