[chuck v.]

Hi everyone -
I have a problem and was wondering if anyone could help. I just replace the fuel pressure regulator on my 1994 Eldorado. I searched previously on the correct way to go about it and tried to follow exactly what should be done. Well anyway I got the new regulator installed but when I put everything back together the car started right away but the engine sounds like it is going to come apart. It always had some lifter noise but now the engine is making an awful racket. a lot of very loud knocking. I shut it off right away took everything back apart and reinstalled. Once again it started right up but still making a lot of engine noise. Does anybody have any idea of what I did wrong.

Thanks, Chuck

 

[9302Eldug]

Not trying to be a wise guy but are you sure that you did not drop anything into the intake manifold?

 

[chuck v.]

Well all of the parts were present and accounted for so I don't know what could have been dropped into the manifold. I really didn't take anything inside apart just swapped the fuel pressure regulator.

 

[Ranger]

Are you sure you pulled and replaced both O rings?
Did you pressurize the fuel system by turning the key on (DO NOT CRANK) to check for leaks?

 

[chuck v.]

Which O rings are you referring to. The only O ring I saw was the one that was on the new regulator. It was on the side that plugs into the fuel rail.

 

[Ranger]

There are two. One is commonly left down in the cup, causing a leak when the system is pressurized.

 

[chuck v.]

Ranger - Thanks for the help I will check the O rings and check for leaks. I will let you know how it turns out.

Thanks again,
Chuck

----------

I just checked the old regulator and I see where the O ring is supposed to be on the part that goes into the cup and it is not there. I then must assume that it is still in the cup. I don't have time right now but I will check it tomorrow. Pretty sure that you are correct. Once again thank you for your response. I will let you know tomorrow when I check it out.

Thanks so much,
Chuck

 

[Ranger]

:thumbsup: Anxiously awaiting the results.

 

[chuck v.]

Sorry I took so long to get back on this but anyway I took everything apart again and there was not another O ring in the cup. I put everything back together and then checked for leaks which there were none. The only thing I did different was when I put the cover back on the manifold I torqued it about as tight as I could get it with just the star wrench. When I started the car it fired right up and the noise is gone. So I guess the fact that I hadn't torqued the bolts tight enough was the answer. Must not have been getting enough vacuum in the manifold.

Thanks for your help

 

[Ranger]

Keep in mind that the manifold cover is supposed to lift in the event of a manifold over pressurization (backfire) to vent the pressure. If you tighten down too tight on the rubber grommets, you'll override this safety feature.