Originally posted by The Darkside Well Bob, you might be right about the fuel pump not keeping up. I just got back from taking another run with the wot maf set at "F" & disabled the tcc lock up & this time I hooked up a fuel pressure gauge to my car & ran it up under my wiper so I could watch it & the result that stands out is :
fuel pressure line off @ 39 lbs.
Boost 24lbs.
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Shouldn't my Fuel pressure be 63lbs. @ wot? I think so , but it only got up to 58lbs @ wot!!!! Well, what do I do now? Fuel pump is a hotwired Walbro 307 & it's about 3 or 4 years old, so maybe it's taking a dump on me. Maybe it's a clogged fuel filter or something else. I will go ahead & change the filter & see if that helps. How do I check for voltage @ the pump?
What other problems tuning I have, could be attributed to directly to low wot fuel pressure?
We just went over this in another thread. The 307's 60psi bypass looks like your brick wall. 40psi+24psi = 64psi fuel pressure you should have. Since the bypass is opening at 60psi your volume/pressure is falling short. You might try opeing up PW to compensate (wrong way)_ or upgrade to a 340 whose bypass is 80psi (right way)
The fact you only got 58psi seems to support this theory.
Well, I changed the fuel filter with a new AC Delco (thanks Bryan) & While under the car I noticed that part of the hot wire kit was hanging loose. It is a black/gray box part w/ a silver tab on it that has a hole in it to ground it I guess? Anyways I could see where it was mounted originally by the guy who put this hot wire kit in & reatached it with a short bolt & nut. It was put right through the bottom of the trunk between the gas tank & the rear bumper.
Anyways, I went for another test run & nothing changed, I still am only seeing 58 lbs. on the fuel gauge @ wot.
I guess I need a new fuel pump, so I called Ramchargers & talked to Kevin(Great guy to deal with) & ordered a new Walbro 340. I sure hope this solves my problems. Any other suggestions, please post 'em...
