having bad car issues, please help!

[Ben Ross]

I own a 1991 pontiac firebird and its symptoms include low and rough idle, loud fuel pump, and after it warms up it slowly looses power until close to stalling. But then I can shut it off and start it again then it runs fine for another little bit then repeats. Please help!

Topic

[Andrew Button]

Sounds like a vacuum leak to me.

[Ben Ross]

I checked for vacuum leaks but haven’t found one. I changed several parts already including the tps fuel filter fuel pump and none have resolved. I will check more thorough for a vacuum leak, thank you for your input

[Ingvar]

You need to check on fuel pressure. Fuel pressure regulator would have been next in line.

[Ben Ross]

Where is the fuel pressure regulator? I’m decently mechanically inclined but kinda new to it. I can replace it if I know where it is.

[Jim Davis]

The Firebird came with 3 different engines that year, which do you have?

[Gary]

[quote=”yamiplier9875″ post=125613]Where is the fuel pressure regulator? I’m decently mechanically inclined but kinda new to it. I can replace it if I know where it is.[/quote] Usually on/near the fuel injector rail.

[Andrew Button]

somewhere on the fuel rail. Usually they have a vacuum line to them. Double check it

[Ben Ross]

Mine has the 3.1 liter v6

[Ben Ross]

I’ll double check the vacuum line to the fuel regulator and check the regulator itself, an important detail I left out is that it had not been registered since 2002 when I bought it which was July of last year. I think it sat for plenty of years.

[Bill]

I would be checking for a plugged catalytic converter. Eric has a video on the subject . Check it out here….

[Ben Ross]

What is odd is that when I removed the vacuum line going to the fuel regulator the cars performance and idle doesn’t change. I think the regulator is stuck.

[Bill]

The only way to test a faulty fuel pressure regulator is with a fuel pressure gauge connected. If the pump is supplying the same pressure the regulator is set to open at, no change in pressure will occure. I had it happen to myself and changed a part that didn’t correct the problem. You would need to plug the return line to the tank to verify that. (Dead Head) If the pressure rises to a high pressure then the regulator may be bad.

[Ben Ross]

But the fuel pump seems to be adding a access amount of fuel and it has pretty bad mpg when it runs good. The fuel pump also will change sound when it starts acting up. It gets really loud.

[Bill]

Another thing I have seen happen is the pump filter in the tank collapse after running for a while. When the engine is shut down it returns to it’s original shape and allows fuel to flow. That would cause the fuel pump to get loud also.
Again, you need a fuel pressure gauge to diagnose that.

[Ben Ross]

I will check the fuel pressure but I have replaced the pump and the filter seemed fine. I also replaced the inline filter in the fuel line. Does it seem improbable that the regulator is at fault?

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