Renney

Hello all, I have a 1985 ford 4x4 that I have not yet finished building but do drive it on weekends. Its a carbed eddy 600cfm on eddy intake 5.0 H.O engine.

Everything on my truck is hooked up on its own circuit with a toggle switch. I have been running an external fuel pump on it for a few years. I have had to replace it once, about a year and half ago. Here lately I lost fuel pressure.

I have a 8 guage ground wire welded to the frame, bolted to engine at the battery ground. Have a 10 guage ground wire bolted from the battery ground on engine bolted to body at the cab and bed. I checked electric hook ups first, and they were ok.

So I figured pump was bad. Pulled it off which is mounted to the frame 18" from rear tank about half way from top of tank. Pump has a filter before the pump. I changed the pump and filter both. Same thing, no pressure.

Pulled it off (MrGasket, cheap if you call $50 cheap). Went to a real auto supply and purchased a $100 pump. Hooked it up and everything worked fine. Drove it 3 or 4 miles and got gas. Sat for 2 days. Cranked it up and would not stay running.

Checked pressure at carb with guage and had "0". Pump was running and was correct volts and not getting hot. I installed a primer bulb behind clear filter at the carb. If I kept giving it a squeez every min or so engine would keep running. When I would stop helping it carb would run dry and engine would quit. Since then I have changed fuel pump agin, two filters and all fuel line from pump to carb.

When I unhook fuel line from tank to pump, fuel pours out. I pulled fuel to carb with primer bulb with pump running till hard and carb and filter is full. Same thing. Runs out of gas. No pressure.

The last thing I have tried was to move pump midway to carb, no luck. ALL pumps I have tried run and sound normal. With fuel line off at carb, fuel just dribbles out and will read O pressue with guage

Have messed with it for about 2 weeks now, and was temped to strike a match, but have just walked away from it. Anyone tell me what I am missing? (Also new tank was put in at pump change done a year and half ago) Thanks for any steering in right direction. With age I sometimes cannot see the forest for the trees.

markshoreline

I'm more familiar with boats than trucks but here's some solutions I'd think about....
Assuming your fuel pump is actually getting enough voltage to adequately pump-(have you measured voltage at the pump?)
There could be a crack/leak in the fuel line- perhaps at a hose clamp,
The fuel pickup in the tank could be clogged,
There could be a kink in the fuel line,
There could be debris in the fuel line due to ethanol degrading the old school hoses.
The debris could also be at the screen (if there is one) at the carb.
There could be debris in the carb.
You could blow air backwards through the fuel line from the carb to clear it. However, I would definitely replace all the rubber fuel lines with ethanol resistant ones in any case.

Renney

Hello markshoreline, first, thanks for the reply. Voltage at the pump was checked first and is +12 volts with two different volt meter's. One of the last things I did was to disconnect fuel line "before the pump". When this is done fuel pours out. I clamped the line then took a waterhose bath to get the the fuel off me (wink). Then I "replace all fuel line and stainless clamps with new from pump to the carb". No kinks, cracks, leaks, or bad fittings. New filter before pump and at the carb. The carb is an Eddy 600cfm which I replaced with a new rebuild of the same that I had. I thank you agin for another brain besides mine thinking. I am so frustrated at this point.

Roger Mabry

Sounds like my truck... bad rubber line... if the pump is working and the fuel is getting to the pump... and all the lines are new and confirmed not clogged up... you have a weird problem..

klricks

Does the truck have dual tanks? You mentioned the 'rear' tank....... If so have you checked the switching valve?

Renney

Hello Roger and yes its worst than weird. I have had my share of problems just as everyone else has. This one has beat me down bad. thanks for showing intrest.

Renney

Hello klricks, the truck had two tanks at one time but the front tank was removed several yrs ago. thanks

Renney

Hello agin. UP-DATE...After giving much thought to my issue all I can say is that,, its whip me good with a switch. All tho I have another "maybe" fix. I do have a "fix". So as much as I hate to get beat, I will try this fix. High pressure pump with a regulator. If I had known how much frustration this was going to be, I would have went this way first. Thanks for helping......Renney

Renney

Issue is fixed...Renney

machviii

Glad you got it worked out. I think you should consider a return line to make sure you do not encounter vapor lock issues, since you are in Florida.

What was the exact problem? You mentioned installing a higer psi pump with a regulator..what pressure are you running.

I have a Holley Blue (i think) but I think I am sticking with mechanical on both my truck and on my 66 Merc with 390. Aftermarket (out of tank) fuel pumps seem to have a ton of problems.