Fuel light on

[I Bleed Blue]

94 7.4 turbo IDI. new to me truck. Been running good for a few weeks, fuel light came on so i changed the filter, light went out for a few days then came back. It had a new mechanical fuel pump but I went ahead and bought a facet electric fuel pump. Went to drive it today and same thing as before 3 gear hard acceleration and fuel filter light comes on. Where should I go looking for issues as I understand the light only come on if the ip goes into a vacuum and my feed pressure to the filter should be 9-11psi with the electric pump.

 

[chillman88]

bought a facet electric fuel pump

Unfortunately that could possibly be your problem. People have been having mixed results with them lately.

my feed pressure to the filter should be 9-11psi with the electric pump

You need to check this out with a gauge. I went back to a mechanical pump for just this reason.

 

[I Bleed Blue]

It’s literally a brand new electric pump and the mechanical one did the exact samething so I’m pretty sure it’s not the issue.

 

[chillman88]

It’s literally a brand new electric pump and the mechanical one did the exact samething so I’m pretty sure it’s not the issue.

It may not be, but I'm just saying don't rule it out as a possibility either. My pump was brand new as well not keeping up.

I'd be looking for sources of air intrusion.

Is your tank selector valve working properly?

 

[I Bleed Blue]

The selector valves switches tanks no problem. I don’t see any leaks so I don’t know if there’s air intrusion

 

[Fordman1920032003]

Definitely add a gauge. Classic diesel sells a nice feed line with a gauge. Also check your grounds and the condition of the plug on the filter housing.

 

[catbird7]

Recently had the same problem and I also started by replacing the fuel filter and considered replacing my 10 year old Holley Red pump when a friend suggested trying a quart bottle of Power Service Clear Diesel fuel & tank cleaner. The container tells you it makes 100 gallons however I dumped a full bottle in 1/4 tank of fuel, drove around for a few days on the other tank allowing it time slosh around in there then switch to the tank with cleaner while driving 3 miles to fill up. Gotta say, it seems to have worked, no more light! It's a little pricey but beats the heck out of new pump or pulling tanks. Good luck to ya!

 

[nhwrench01]

i had the same problem, but on a n/a. same setup, facet pump and a small filter before the pump. the fuel filter light would keep coming on. id change the spin on filter, and it would be good for a while. ... hear me out on this..
I think removing the spin on would let the fuel in the line back flush the filter and push the crap back a ways. 3 or 4 spin on filters later, i knew there were other issues. i checked all the lines and fittings. Then i changed the small filter before the pump and cut it open...
WOW, full of crud and who knows what. worked fine after that, untill i installed a turbo set up, the facet pump does not have enough flow for the increased fuel need of the turbo engine. the only change was adding a turbo, straight pipe and turning up the ip pump 2- 2.5 flats. ( was only at 1-1.5 flats before). i added a holley red and its been fine . get a fuel pressure guage and check it as you drive , my facet was at 3 psi. at idle and went to 1 psi driving... not good. Hope this helps.

 

[I Bleed Blue]

Facet pump is not the problem. Dropped the tank and found the pick up was full of crap! Typical shower head screen had come apart and got sucked up.