Buddies formula is breakin up at higher R's. When I went to take a look at it I basically knew the answer right when I started it, it took a few (5 or so) seconds to start up, not normal for his car. It starts breakin up at about 5000ish, and is sorta sluggish all the way up, but not really sluggish. Checked the FP and it was about 20 psi. Replaced the filter, still around 21 or 22 now. It obviously should be the pump, but im not forgetting something cheaper or easier for him am I? Like the FPR or something.

 

If thats all that sucker is putting out at idle theres something wrong with either the fuel system or the pump.

 

You must not have read the post well. I knew that, I just want to make sure it cant be anything other than the fuel pump, I know its in the fuel system, but the pump isnt the easiest thing to change, dont want to go cutting a hole in the back floor when it could be an FPR or something.

 

I'm sorry , I read it fine I just thought you wanted reassurance. Since the pressure is so low the only thing it could really be is either a kink in the line, a clogged filter, a faulty regulator or the pump. Its possible that it could be ignition related, but since the FP is so low (I've owned 7 FI GM cars, all TPI or LT1s) it really has to be there. All the cars I have seen and own have stock pressures from 39 to 48 PSI, the ones that had 39 after adding an adjustable regulator were able to be bumpred up above 45 and hold that all the way to 6 grand under load. The regulator really has only one part that could be bad and thats the diaphram, but if there is no fuel on the vacuume side then it is good. Kinks you can see(except in the tank), You have a new filter, so the only real culpret can be the pump or the voltage to the pump. Confirm voltage at the harness as it goes up to the tank. If it is low the pump will not turn as fast. I really think though that its probably the pump.

 

Thats what I thought. Walbro 255lph a good one for a mild head/cam car, NA??

 

Yep, go with the Walbro. Very nice pump.

 

how can you tell what your pressure is. do you have to have a guage or is thier a tool or something

 

fuel pressure tester. guage attached to long hose that screws onto the schraeder valve on the back of the fuel rails.

 

Yeah, make sure you check the pump voltage first.

Brandon

 

Where will I find the wire to test pump voltage? If this changes anything we used the fuel pump lead by the PCM to turn it on, not the key, also ran it at idle.

 

If you crawl underneath youll see the harness for the level sender and the pump coming down the front of the tank in the middle on the drivers side of the hump. The largest gauge wire is it (not sure of its color) you can either follow the wires up to the connector, or you can probe it as close back as you can.