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Looking for some help with this beast

tomtom123 said:
Replaced the pump with a new stock pump and now I have 70psi at idle. Did nothing other than the new GM stock GTP pump for my 99GTP =/
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I didn't know that you changed out the pump right when this started. Now I definitely think you have a blocked tank return line or you swapped the two lines.

It could be that you switched the lines at the pump side when you changed it out. That would have you feeding fuel into the tank return port on the regulator through the return line hooked up to the fuel pump outlet. That would push the regulator open to full pump pressure. The fuel filter is producing the back pressure on the fuel returning to the tank through the supply line. Maybe the filter has a check valve inside and the pump has a built-in bypass regulator at 70 psi?

What happens to the pressure when you put load on the engine? If it varies then you have no regulator action and that leads me to believe that you switched the lines. If it remains stable then I think you have a kinked or blocked return line and the pump has a bypass regulator inside set at 70 psi.
 


Shmoke said:
I didn't know that you changed out the pump right when this started. Now I definitely think you have a blocked tank return line or you swapped the two lines.

It could be that you switched the lines at the pump side when you changed it out. That would have you feeding fuel into the tank return port on the regulator through the return line hooked up to the fuel pump outlet. That would push the regulator open to full pump pressure. The fuel filter is producing the back pressure on the fuel returning to the tank through the supply line. Maybe the filter has a check valve inside and the pump has a built-in bypass regulator at 70 psi?

What happens to the pressure when you put load on the engine? If it varies then you have no regulator action and that leads me to believe that you switched the lines. If it remains stable then I think you have a kinked or blocked return line and the pump has a bypass regulator inside set at 70 psi.
Click to expand...

Well, I can double check the lines going to the pump canister. But the last person to touch those was a shop. How would I be able to tell which line is what when I'm back there? I never saw any markings on them.

And I was stupid and took the fuel pressure tester back after I found out I had 70psi at the rail which later I realized I should have kept it hooked up and drove to see how everything went..

Also, when I changed out the pump the car ran fine for a while. Idled like it should and everything. Now after I got it tuned was when it started idling weird. But the tune that was put onto my car ran fine on a Daytona 500 car running an xp cam.

When I first got this car even completely stock, at WOT it would pull timing down to 8* even after I put a downpipe on it and it saw no knock. I'm not sure why it would do that because thats when the tune was stock and I had no mods except a catted downpipe and 0 KR.

I got it kinda retuned and now I'm not seeing much knock until about 5500rpms and then it creeps up. And after about 60 there is almost always knock.
 
Okay sorry I haven't been able to spend time outside with this thing, but I checked the fuel lines at the pump and the largest line is at the farthest nipple from the driver, the center line is the smallest line, and the second biggest line is the last line. Does that seem correct?
Also, found my old rail! Just have to get a day where I still have some light after classes/work.
Question about IAC. What does it do and when does it do it? If the car is idling, should it act up when unplugged? Or does it only really help when cruising?
 
Fuel lines are fine. Replaced the rail and it doesn't have thst clunking noise in that disk now, obviously since the rail I just put on doesn't have that disk =P
Ticking coming from it sounds like the front header and some from front lifters under the valve cover it sounds like.
 
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