[500plus]

any help would be appreciated!!! new Holley
blue fuel pump..already tried another..the problem is after running for about 5-8 minutes the fuel pressure drops from 8psi to 1 or 1 1/2psi! 1/2" lines from tank sump going into fram filter then pump to more 1/2"
lines alll the way to front of car into regulator then to carb..pressure gauge just
before carb..pumps are mounted in the area above the rearend..is this the prob? 1st time
using electric pumps.like I said good pressure until after running for a few minutes. the exhaust turns down in front of rearend and nothing seems to be close to the lines which runs on the outside of the frame rail just past the leaf springs..Thanks for any info. Bill

[500plus]

any help would be appreciated!!! new Holley
blue fuel pump..already tried another..the problem is after running for about 5-8 minutes the fuel pressure drops from 8psi to 1 or 1 1/2psi! 1/2" lines from tank sump going into fram filter then pump to more 1/2"
lines alll the way to front of car into regulator then to carb..pressure gauge just
before carb..pumps are mounted in the area above the rearend..is this the prob? 1st time
using electric pumps.like I said good pressure until after running for a few minutes. the exhaust turns down in front of rearend and nothing seems to be close to the lines which runs on the outside of the frame rail just past the leaf springs..Thanks for any info. Bill

[boykoman]

This may sound silly but is your battery and charging system up to the task.I experienced the same thing and it was my charging system not enough amps to run fans,electric waterpump,ect.I would start the motor a few minutes later the fuel pressure would drop.Put in a new alternator 80 amps at idle and 140 amps at higher rpm now no problem.Also have you had the regulator checked?I may be way off base here Im just a novice learning.

[mike nixon]

are you sure the fuel in the tank is clean? what i'm getting at are debris clogging the filter at the end of the sump pickup or has it been removed? mike

[500plus]

electrical is all new and working great
the tank is new with a rear sump installed and running two 1/2" aluminum lines..one for the nos and the other for the carb.each with their own fuel pumps..just got this bird running and haven't tried the nos yet..
the filters are the fram race units, I also checked the element and it is clean.. Thanks

[PONTIAC DUDE]

8 psi is to much anyway. 7 max. Is this after a run in the traps or slowly fading at an idle? Or just driving down the road? Not to seem like your stupid, but this happened way back in 69. A customer installed an inline filter and the car would slowly die going up hills, culprit: filter installed backwards, turned it around and he was a happy camper. Pull your filter apart, check for trash or water in the system as this will create havoc in your fuel pressure. Teflon tape caught in the fuel, same thing. What size wire are you running to the pump & also what AMP switch. I've seen 10/15 amp switches loose supply after they get hot. Run at least a 20 rating switch and run the pump on it's own power supply. Don't piggyback off any other source. Good ground? double check. Later dude. http://sites.netscape.net/pontiacdude428/homepage. CHECK IT OUT more Butler weekend pics

[boykoman]

Put a good relay in as well for the pump.Good added insurance!!

[Bracket Racer]

You do have those pumps mounted below the sump in the tank don't you? Those Holley's are pushers not pullers and if you don't have them mounted below the sump they won't work worth a d**n!

[500plus]

Ii will have to remount them....they are above the sump level...I was wondering if that could be the problem..Thanks