Need hellp on this.

[vampyr]

OK here is the problem in a nut shell.

I have a 1997 3.8 I have just changed the head gaskets on the car. These problems were there before I changed the head gaskets.

Problem number 1 the car will not hold fuel pressure without the pump running., I have changed the pressure regulator and it is still doing the same thing.

Problem number 2 the car is idleing rough and low and throwing a random multiple missfire code.
I have changed all of the sensors on the car with the exception of the MAF and the TPS. there are no vacume leaks that I can find. the wires and plugs look good. I have changed the coils and the ignition module.

I am at my wits end with this car. I don't know where to go from here. I am litterally about to just sell it.

ANY ideas on this?

[timthescarred]

Re: Need hellp on this.

could be an injector problem. If one is stuck open you will lose fuel pressure and misfire due to rich condition, you could also have low fuel pressure due to a stoppage or leak somewhere in the line.

Basics first, put on a new fuel filter. test the fuel pressure at idle should be somewhere 36-50psi go rent some noid lights and check the injector are receiving the proper signaling.

[vampyr]

Re: Need hellp on this.

At idle the fuel pressure is about 45 psi... NOID lights? If I had a bad injector wouldn't it show on the plug? Would it cause the random multiple missfire? Would it run rough at other times? As always thanks for the help..

[ssms5411]

Re: Need hellp on this.

Injector leaking after the car is shut off so stuck open and bleeding out the PSI of the rail. I would say rich condition , may smell like fuel and I think it would throw a random misfire. Mine did when one was stuck closed, PO300 is all I got ,no injector # which pissed me off and spent alot of money on it throwing part at it until it was found. Good luck.

[timthescarred]

Re: Need hellp on this.

On the sequential fires one cylinder misfiring bad enough causes others to misfire, especially on the same bank, Thats why you get a multiple.

NOID lights are small lights that you can get from any autoparts store, usually 30 to buy a set, or rent 'em for the same amount and get the money back when you return them. you unplug the injector clip and plug the NOID into the clip then turn the car on, the light should flash on/off fairlly rapidly. If it doesn't come on, that injector is never opening, if it comes on and doesn't go off, the injector is staying open. This tests the electrical side of the injectors and will let you no if there is a bad wire, or the PCM is sending bad signals.

If some carbon has caused the injector to stick you can run a can of seafoam in the gastank and that should help.

45psi at idle sounds good. Is the idle always rough? or after its warmed up?

[vampyr]

Re: Need hellp on this.

Idle is always rough the car normally idles at like between 700 and 950 rpm I will look into the noid lights. Thanks again all