fuel pressure, please help, cpi?

[demotim00]

Originally Posted by BlazerLT

How old are the cap rotor and wires now?

Air and fuel filters are about 1 month old, and the plugs, wires, cap, and rotor are about 3 weeks old. Please keep in mind though I found out today that I am laid off from my job, so I wont be spending no more money than abosulety needed just to keep it running proper, so any parts that do not need replacement, I am not going to do. Since plugs are fowled though, and don't cost very much at all, I will do that, but as far as wires, cap, or rotor or anything else, I am not going to replace unless they are needed, or unless someone can come up with a good reason why they need replacement.

[BlazerLT]

Being that new I doubt they are defective.

What plugs did you use?

Did you set your timing with the timing wire disconnected from the PCM under the glove box yet?

[demotim00]

Originally Posted by BlazerLT

Being that new I doubt they are defective.

What plugs did you use?

Did you set your timing with the timing wire disconnected from the PCM under the glove box yet?

I used Bosch Super plugs gapped at .045. No I havent set or checked the timing myself, since I don't have a timing light. The shop said that was one the first things they did was check the timing, and that it was where it should be.

[BlazerLT]

You might want to have a friend check that out separately with the timing unconnected.

[demotim00]

Originally Posted by BlazerLT

You might want to have a friend check that out separately with the timing unconnected.

So I'm taking it that you got think the timing could be off than? If so, could the spark plugs being fouled/and or the timing being off cause a rattle noise that sounds like a heat shield or manifold being loose? I had the same noise that was there before the cat was changed, and I was told it was the cat, but than even after that been changed its still there, but instead of sounding like its coming from the cat, it sounds like its coming from the back of the motor, and is alot quiter than what it was before the cat was changed. Would that be a spark knock from the plugs being fouled, or what? I tend to know alot about vehicles, but spark knock and timing are two things Ive never dealt with, and by far I'm no mechanic, and therefore not really sure.

[BlazerLT]

Timing would cause the plugs to foul, have poor performance and would dump unburnt fuel into the cat which would ruin it.

I would rent a timing gun and check base timing with the timing wire disconnected.

[demotim00]

Originally Posted by BlazerLT

Timing would cause the plugs to foul, have poor performance and would dump unburnt fuel into the cat which would ruin it.

I would rent a timing gun and check base timing with the timing wire disconnected.

Ok thanks, Ill have to check in to that. Personally I don't think its dumping any unburnt fuel now, I know the cat was ruined from when the CPI was leaking and dumping the fuel, and I know the plugs and all was changed after I changed the CPI, but than a couple days after the plugs were changed the CPI started leaking again and was replaced under warranty, and I'm thinking and thats what the shop said, caused the plugs to foul. However I will look in to the timing. Thanks for your input.

[taylorman]

I just had a similiar problem on my 93. I went to advanced auto and purchased a 40.00 dollar fuel pressure tester and checked it myself. My pump kicked up to 56 psi but instantly dropped to 20 when the pump shut off. Therefore a put a new 75 dollar advanced auto pump in and my jimmy runs great.