fuel pressure

QUIP'6'

Brian Roman
Joined
Nov 26, 2003
Need Help With Fuel Pressure. I Have A Walbro 340 And Hot Wire Kit Its 4 Months Old. Everything Ran Fine Till Now. I Have Static Set At 43# Line Off And Running 17# Of Boost When I Jump On It It Only Goes To 50# To 52# It Should Go To 60# My 02 Volts Are 650. When I Spool It Slow It Is One To One But At Wot Is When It Does This. What Is The Problem Here? I Also Changed Fuel Filter To See If It Would Help But No Change Tonight I Put Stock Regulator On And It Does The Same Thing. Please Help Me
 
clamp off the return, with vise grips, and turn the key on, only for a few seconds, and watch your gauge, should go up to 90 psi or more,

broken hose, off the fuel pump
clamps not tight, on the fuel pump
vacaum leak, from reg.
 
donZ said:
clamp off the return, with vise grips, and turn the key on, only for a few seconds, and watch your gauge, should go up to 90 psi or more,

broken hose, off the fuel pump
clamps not tight, on the fuel pump
vacaum leak, from rwhat if it doesnt and the hoses are tight on fp
 
thanks i will try this tomorrow also if it drops wouldnt that mean the injectors are leaking
 
do you know, FOR SURE, that little hose is in good shape, and tight
i had the same problem, wasted a lot of time, and parts, to find out it was that little hose, i was to lazy to drop the tank,and check,
 
no i dont but someone else said the worm gear didnt tighten it good enough to seal and when he bench tested it id was pissing out the hose on the pump so he bought fuel injector clamps
 
Brian-
I think you should explain some more what you have done to the car here lately.

If the car spools in the driveway to 60, but under a load it drops to 50, then i would say hose clamp or split hose before pump.
Since the issue is only under a load, wonder how many brand new 340 are bad?????????????????????????????????? doubt it right?

Are you sure you installed the grounds at the back of the tranny when you just did the convertor?
 
thanks don z but it does this only a wot when i brake spool it and build 14# in drive it shows 57# but when i drive and punch it and watch both gauges rise the boost goes to 17# and the fp stops at 52# should stop at 60#
 
went out and put 25# of air in fp regulator and i got around 70# so my regulator is ok and also my pressure would bleed to 0 in 1 to 2 min. so i checked the hose i got connected to fuel rail and it was loose so i got 4 cranks with vise grips and now my pressure takes 85 min to drop to zero is that ok i didnt get to check it driving to see if it goes to 60 # while driving cause it is raining will check tomorrow and will post results but do you think it was bleeding cause the hose was loose by the way its a fuel line connected to my gauge mounted behind my hood
 
well guys i thought i fixed it dropped the tank replaced hose and put on fi clamps and changed sock worked for a couple hours and now its doing the same when i nail it it goes to different readings 50, 55, 58, and sometimes it goes stays at 43 or it rises slow wned i spool it slow then when i punch it it sometimes drops to 43 static pressure settting. sounds like a regulator do you guys think? tommorrow i will buy a stock one to see if it does this so i can rule out regulator or pump i doubt its the pump because i always have 43# it doesnt seem like its regulating it very well.
 
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