Looking for some help...

[jmerk]

Hello, I have a '96 Lumina, 3.1L w / 157K miles. I've owned it for about three weeks now. It has been starting and running great but occasionally it will idle a bit rough after it starts for about 5 seconds, then it smooths out. This weekend however, after a start, it idled real rough but did not settle down and eventually killed. I restarted it, idled rough and killed again but would not restart. I had a service engine light on that came on about 6 days ago. I borrowed a scanner and found two codes. P1870 manufacturer controlled transmission and P0300 random/multiple cylinder misfire.

I visually checked for spark from each coil pack and had spark on each one. The plugs and wires where replaced recently, they have no corrosion in the terminal areas at all, they look very new. I depressed the fuel test connection valve at the end of the fuel rail and I have fuel present, but I know that isn't real definitive. It seems like a fuel problem. Is there a filter that could be plugged? Fuel pump pressure? Injectors that are plugged? Not sure where to look next. Can anyone offer some guidance?

Thank you!

Jeff

[richtazz]

you need to hook up a pressure tester on that valve. You should have 41-45 psi, key on/engine off. There is a fuel filter, it is located near the fuel tank at the back of the car.

[jmerk]

Thanks for the tip, I didn't go out and buy or borrow a pressure test kit, but I did depress the stem on the test valve again and found NO pressure at all. A dribble of fuel came out for a instant then nothing, with the key in the run position. I even cranked it ove for a few seconds. Then tried again, same result NO pressure at the test port. I removed the fuel pump relay and bench tested it and it works great. I also tested for voltage at pins 1 & 2 which fire the relay, and checked pins 3 & 5 which switch on 12v to the pump I assume. Pin 5 has 12v present, and with a relay thats working can I assume the fuel pump is the problem or is there something alse in the circuit I don't know about.

If it is the fuel pump, is that a fuel tank removal job or can it be done through an access hole in the floor of the rear seat area? Either way, I will probably end up letting a service center do it for me. Don't feel like blowing myself up.

Thanks again for the help

Jeff

[tblake]

need to drop the tank