Fuel Pressure Problems - Again
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TECH Enthusiast
Joined: Dec 2001
Posts: 553
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From: Columbia, MD
Fuel Pressure Problems - Again I am plagued with this issue again after resolving it the first time several months ago. The original problem was that the hose in the fuel sending unit kept coming loose. But this is clamped securely now. This time, apparently something else is "pinching" the fuel delivery somewhere. It's so bad that as soon as I drop the hammer, the fuel pressure almost instantly drops of the chart. If you let it, it will drop all the way to zero PSI. 
Any ideas on where to start troubleshooting this?
I have a T-Rex inline, and Walbro 340 in-tank, and 50# injectors. This setup previously held constant 60PSI, and now all of the sudden the fuel pressure is inversley proportional to the engine RPMs.
I appreciate any help.
Any ideas on where to start troubleshooting this?I have a T-Rex inline, and Walbro 340 in-tank, and 50# injectors. This setup previously held constant 60PSI, and now all of the sudden the fuel pressure is inversley proportional to the engine RPMs.
I appreciate any help.
TECH Enthusiast
Joined: Nov 2001
Posts: 650
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From: Toronto, Canada
Re: Fuel Pressure Problems - Again I know this sounds very basic, but when was the last time you changed your fuel filter. You could have put a bad tank of gas in there or even have some contamination that is clogging up the filter.
I would check that first and go from there.
I would check that first and go from there.
TECH Fanatic
Joined: Dec 2001
Posts: 1,220
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From: Germantown, MD
Re: Fuel Pressure Problems - Again Hey crunch, sounds like the same, or very similar issue I'm having. Here's the repair list I've put together.
1st, Upgrade fuel supply line to an -8AN line up to the rails. Plumb into the tank so there is no bottleneck. I'm gonna upgrade the sucky fuel filter I got and i think i'm gonna go with the LS1speed -8AN filter, that sucker is BIG! My thought is either a restriction in the line, or at high flow rates I'm getting cavitation in my line disrupting the fuel flow.
2nd, after the lines have been upgraded if the problem still exsists, swap out the fuel pump. there's a posibility that the pump is no good. if i do this I'll probably gonna bite the bullet, buy a second pump and shoe horn that sucker in there with a hobbs switch to engage it under boost.
3rd, this extreme idea is to pretty much to copy Harlan's new setup. He's basically rigged a 98 fuel tank like a fuel cell. Complete with sump and massive external pump. This one will be tricky and hopefully Harlan will share his tricks to getting this to work. I'd have to do more research on this one to find out exactly what would need to be done to make it work correctly. But it's an idea. I doubt I'll need to go this far anytime soon. But like you I have plaging WOT fuel supply issues. Let me know what you've tried.
Are you boost referenced? What FPR are you using?
Mike
1st, Upgrade fuel supply line to an -8AN line up to the rails. Plumb into the tank so there is no bottleneck. I'm gonna upgrade the sucky fuel filter I got and i think i'm gonna go with the LS1speed -8AN filter, that sucker is BIG! My thought is either a restriction in the line, or at high flow rates I'm getting cavitation in my line disrupting the fuel flow.
2nd, after the lines have been upgraded if the problem still exsists, swap out the fuel pump. there's a posibility that the pump is no good. if i do this I'll probably gonna bite the bullet, buy a second pump and shoe horn that sucker in there with a hobbs switch to engage it under boost.
3rd, this extreme idea is to pretty much to copy Harlan's new setup. He's basically rigged a 98 fuel tank like a fuel cell. Complete with sump and massive external pump. This one will be tricky and hopefully Harlan will share his tricks to getting this to work. I'd have to do more research on this one to find out exactly what would need to be done to make it work correctly. But it's an idea. I doubt I'll need to go this far anytime soon. But like you I have plaging WOT fuel supply issues. Let me know what you've tried.
Are you boost referenced? What FPR are you using?
Mike
Thread Starter
TECH Enthusiast
Joined: Dec 2001
Posts: 553
Likes: 0
From: Columbia, MD
Re: Fuel Pressure Problems - Again I'll forward this post to Jason at FBC. He's done all the work from the blower to present.
Edit: And who are the chicks in your sigs, man!!??
Edit: And who are the chicks in your sigs, man!!??
Trending Topics
Re: Fuel Pressure Problems - Again I had a similar problem about a week ago...but my problem started off with me suddenly having 80psi at idle.
Then the pump came down with the dropping fuel pressure problem.
Then the pump came down with the dropping fuel pressure problem.
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