still low fuel pressure....someone find me a river for it!

[binks0678]

well i put in a ton of work on my truck and im still having issues.its an 87 ext cab 2.9l 4x4. i replaced both fuel pumps because it would occasionally completely lose fuel pressure. well after i replaced them both i started it and it has pressure but will just barely run, misses a lot, and doesnt have enough power to move its self. also i have to feather the throtle to even keep it runnin. i get under the truck and i can hear the in tank pump kick on but not the in line pump. im 99% sure i correctly hooked everything up but im goin to take the pump off and check again. any ideas guys? also i think this problem is not at all related to the problem that made me change the pumps because it acts way different. any help would be great!

 

[DisturbedMXer8]

Check your fuel pressure regulator. Disconnect the vacuum hose from the back of it and check for fuel coming out, and listen to see if your engine RPM increases. If you have fuel coming out the back, it's ruptured and needs to be replaced. If your engine doesn't increase in RPM when you disconnect it, it's probably seized up and will need to be replaced. Those little FPR's are the cause of 90% of fuel related issues on these trucks, at least in my experience.

 

[RustedRanger]

Better yet use a fuel pressure gauge. Mine didn't leak any fuel and it was still bad.

 

[binks0678]

dam is that the part that i have to take the transfer case back off to get to? and yes i have a fpr layin around for it somewhere so maybe ill just go ahead and throw it on there anyway.

 

[binks0678]

edit im guessin the thing next to the transfer case is not the regulator but what is that thing? next to the transfer case has fuel lines coming out of it and a metal housing.

 

[binks0678]

well i replaced the fuel pressure regulator and still the same. when i changed the tranny is there anything i could have broken from the motor moving? the distributor cap thing still looks good it didnt touch the firewall. would only the in tank pump working give it just enough fuel to barely run? im still not hearing the in line pump click on.

 

[holyford86]

if your inline pump is not running then that would cause it to just barely run, you will need to verify that you are getting power to the pump itself. If you know the pump is not running throwing parts such as fuel pressure regulators and such at it won't solve the problem.
Once you get the pump running than you should see what you are getting for fuel pressure. If the fuel pressure is good then check elsewhere for your issue. The thing next to the transfer case is not a fuel pressure regulator, that is the fuel canister.
Make sure that the wiring for the o2 sensor is not pinched between the engine and transmission, and verify that the small orange ground wire to the back of the passenger side head is intact and in good condition.
If you are losing fuel pressure intermittently then the problem is likely the fuel pump relay next to the air-box under the plastic cover, or the inertia switch down under the dash in front of where the passenger's feet go. Once you verify that you are getting fuel at a good pressure and that the wiring is in good condition, if it still runs like crap you need to pull codes and see what that tells you.

 

[binks0678]

thanks so much for all the info holyford. i did think maybe a ground could be it, i may have possibly knocked it loose while changing the trans. i finally verifyed that the in line pump is in fact working and fuel pressure rose although im not sure to what i couldnt get ahold of another fuel pressure guage after messing with the pump. im thinking ground could be it but my 02 wires look pretty shitty to so i will see if those are still all intact. i also have another inertia switch laying around that i can change if i need to. how should i check the relay? seems like that could be it to.

 

[binks0678]

also my check engine light is broken, has been for years so im assumin its throwin codes left and right ill get it scanned tomorow if i can get ahold of a scanner. (cant get the dam thing to drive to the auto parts store)

 

[ronclark]

why get a scanner you just need a analog volt meter its really easy to do.
88+ were nice since the check engine light blinks, not need for a volt meter

http://www.therangerstation.com/tech_library/OBD_I.html

 

[binks0678]

does anyone know if there is a seperate relay for each fuel pump? if they run on the same relay that would rule that out since my in tank is clearly working. i checked all my grounds and they are good. i replaced the filter and checked the lines and they are good im really getting frustrated. having a mechanic friend come have a look at it today. i have also heard sometimes brand new pumps simply dont work right outa the box?

 

[Psychopete]

They run off the same relay. Check of ECC-IV diagnostics in the tech library on how to pull codes. Seen a really good article on a Mustang forum that really broke down the procedure from a google search. Auto stores won't do it for you since it's so old.

Pete

 

[beauknowz]

i had similar problem, i did both pumps and had a FPR rigged up to see through my windsheild.
it was suggested to blow my fuel lines. THAT was my problem. clogged fuel lines.

it boggs a little now and then, so i will reblow them and remove the fuel resevoir and do the same.

the fuel resevoir may be the thing you were asking about by the tcase.
its inline between the tank and frame mount pump.

 

[redeyed]

the thing on the frame by the transfer case I beleive is the canister that holds fuel filter in side. 99% sure.

 

[redeyed]

Yup, that's where the fuel filter is. Just changed mine, the cover screws off and there is actually a paper filter. The Haynes manual says that Ford say's the filter should last the life of your truck. When I took out the old one it was black and real shitty looking and my truck has just over 100k. Don't get me wrong, it sucked. Gotta remove the t-case skid plate and plan on getting covered with gas no matter what you do.