runs great when cold

[michael_k0]

1995 b'ville supercharged, runs fine for about 30 minutes then acts like its running out of gas, replaced fuel filter which was very clogged, but it still does the same thing. If I shut it off and restart it, it runs fine for a few minutes. any ideas???

[GTP Dad]

Bad TPS, Ignition Module,fuel pump or injectors. These are the four most common items that will cause this problem. Check the fuel pressure while it is doing this to see if the fuel pressure is dropping. If the fuel pressure is good check the TPS voltages and then the ignition module.

The final possibility that may cause this problem may be expensive. How many miles do you have on the vehicle? If it is high mileage you may have bad injectors. When they heat up the resistance gets too high and the injectors don't work correctly. This is a more common problem on 2.8's and 3.1 but it can happen on high mileage 3.8's. Check the other items first, if they check out then check the injectors. I hope I am wrong but this may be your problem.

[johnny74839]

Originally Posted by GTP Dad

Bad TPS, Ignition Module,fuel pump or injectors. These are the four most common items that will cause this problem. Check the fuel pressure while it is doing this to see if the fuel pressure is dropping. If the fuel pressure is good check the TPS voltages and then the ignition module.

The final possibility that may cause this problem may be expensive. How many miles do you have on the vehicle? If it is high mileage you may have bad injectors. When they heat up the resistance gets too high and the injectors don't work correctly. This is a more common problem on 2.8's and 3.1 but it can happen on high mileage 3.8's. Check the other items first, if they check out then check the injectors. I hope I am wrong but this may be your problem.

any more ideals on this problem, have the same,98 bonneville 3.8

[michael_k0]

Drove all over town with a fuel pressure guage taped to the windshield and found out it is losing fuel pressure, it drops down to zero. Maybe a bad fuel pump. Thanks