No power accelerating, fuel problems?

[lost86broncoii]

Ok so the past month or so my 86 bii has been having a problem with the entire fuel system, i replaced the high pressure pump, the relays, and the fuel pressure regulator(about a year ago) i can hear humming and fuel move in the tank when i turn the key so i am assuming the in tank pump is good but i haven't double checked to make sure. so the problem is idle and start ups got a little rough then i notice a hesitastion in acceleration just when i was getting on it, now its gotten alot worse i can't get on the highway cause the truck won't accel enough, the rpms just surge like she loses fuel pressure, could the in tank pump be out and not pulling enough fuel for the high pressure to pump? i pulled the vaccum hose to the fpr and it had a faint gas odor, could it be a faulty one, i know i changed that regulator like three times in a row on my old bronco ii cause i kept running the tank dry(broke fuel gauge ) any input or help would be great i am thinking about trying another pressure regulator? any way to check the tank pump easily other than listening?

also i heard so grinding from my rear end the other day, not sure how that would or could affect my engine rpms but i figured i'd mention it any way, i sucked the old gear oil out with some small metal shavings and put new oil, but no track/slip-additives(wasn't sure if i needed it)



Thanks for the help

 

[modelageek]

Do these things have a fuel filter?

 

[lost86broncoii]

yes, sorry i meant to put that i had changed that too, about 8 months ago. could running it empty twice have clogged the drop in cartridge filter already?

 

[modelageek]

yes, sorry i meant to put that i had changed that too, about 8 months ago. could running it empty twice have clogged the drop in cartridge filter already?

on an old truck like that i think it is possible. . imho fuel filters never get changed enough..........is it an inline filter like most of the other fords. if it make sure it is facing in the right direction

 

[modelageek]

I just looked on rockauto for a fuel filter. it shows both and inline and a cartridge. I assume you change the cartridge. Make sure you don't also have an inline one too

 

[IMenriched]

I too could hear and feel the in-tank pump run as well.
I finally went to change it & discovered that the short section of hose connecting the pump to stem pipe of the in-tank unit...was deteriorated and missing.

I just replaced the whole unit, pump and sending unit as well...figuring that it was old and the fuel gauge wasn't working correctly either.

 

[lost86broncoii]

what was your truck doing? same kind of thing as mine, did you change out the sending unit and the in tank pump or just the sending unit?

 

[IMenriched]

what was your truck doing? same kind of thing as mine, did you change out the sending unit and the in tank pump or just the sending unit?

In My case ...it ran surprisingly really well for the 1st 10-20 miles....farther if it didn't involve stop and go traffic. I noticed if I had less than a 1/2 tank of gas it was more problematic. After fully warm, it would spit and sputter then take off like nothing was wrong. Towards the last, it would die and leave me sitting. Let it sit for a few minutes (15-30) and it would allow me to get home & no I didn't take far or remote locations.

It would act like classic TFI module issue. I checked the fuel pressure a few times, but at the last time I tested fuel pressure, every time , just prior to it sputtering the fuel pressure would drop dramatically. It was a bit hard to see, I had to watch the gauge closely, but maybe I had 1 second of pressure drop then it act up. and usually after throttle tap


Yes I replaced the whole thing...pump and sending unit.

 

[lost86broncoii]

ok thanks for the help i guess i'm off to the parts store