pegged lean at cruise and constant creep to lean? (NON turbo NON dodge)

[thefitisgay]

this is in my 92 f150 4.9L 5spd 4x4 with 140,k miles im asking here and not the ford truck forums because the people here are actually educated and arent dumb as sin like on the truck forums

it should get more than 11 mpg with the ac off
ok so like the title says it constantly creeps to lean..... untill its at 17 on the wideband and is coughing

if i get on the gas they it goes into a nice pocket of like ya kno 14.5 to 13 something but driving like that is pretty lame all the time and when i get on the gas it runs like crap a little then like clicks into a good running phase and the lean issue goes away simultaneously with the click

if i unplug my fuel pessure regulator it keeps doing the same thing but it will bounce to rich and stuff ya kno but does ok

i think its clogged up injectors? it could also maybe be a bad map right?

im really not trying to just throw parts at the thing but i want to fix why its getting 11 mpg with stock tires and 3.08 rears specially since its 5 speed

[89ShelbyGuy]

First thing first....whats the fuel pressure..how are you checking it? Your fuel pump could be dieing....how about the fuel filter...whens the last time you replaced that...

And as for the gas mileage...my 08 ram with the hemi and the mds was getting 12 mpg...with no ac on....so...

[thefitisgay]

i just changed the in line fuel filter like yesterday? or the day before... i think i should have passed on the filter that was missing the rubber caps

i dont have a fuel pressure gage.... :/ and my rear tank has a hole in it so i cant just flip a switch and see if it works better

but if i floor it it runs fine.... stays right around 14... i just dont want to drive with the on off switch so to speak....

[turbovanman²]

Inline6 or V8? Did you recently buy it or have you had it for years?

Any codes.

YOU MUST verify fuel pressure as the fuel pressure reg's are known to shitt the bad, as do the MAP sensors. If you don't have access to a multimeter or labsope, scanners then all you can do is guess.

If all that is good, then its most likely dirty injectors, you'll need to remove them and have them cleaned or find a shop with a pressurized external unit and clean them on the truck using a high grade commercial cleaner. Intank cleaners will not do it.

How is oxgyen sensor?

V8's get crap MPG, inline 6's much better.

[thefitisgay]

if its so rich that its reading lean wouldnt the gage like wrap around from the left so to speak? like go 13 12 11 17 16 ???

and if its sensing lena wouldnt it dump fuel and give me bad mpg and never use the fuel right cuz its squirting in there like a suirt gun instead of like areosol?

and my fuel pump is pretty noisy

[thefitisgay]

Inline6 or V8? Did you recently buy it or have you had it for years?

Any codes.

YOU MUST verify fuel pressure as the fuel pressure reg's are known to shitt the bad, as do the MAP sensors. If you don't have access to a multimeter or labsope, scanners then all you can do is guess.

If all that is good, then its most likely dirty injectors, you'll need to remove them and have them cleaned or find a shop with a pressurized external unit and clean them on the truck using a high grade commercial cleaner. Intank cleaners will not do it.

How is oxgyen sensor?

V8's get crap MPG, inline 6's much better.

4.9 6 cyl

the v8 fuel regs ---- the bed the l6's dont run the same unit

o2 is a brandy new 3 bar autometer spliced into the bosch harness thats just dangling there now haha

so the map is a possibility too?? right?

it used to throw the egr code i have since disconnected all the vac lines except fuel reg map and hvac to eliminate vac leaks

---------- Post added at 05:45 PM ---------- Previous post was at 05:43 PM ----------

if i make an injector cleaner tool would anyone wanna buy it? or we could just pass it around

[RoadWarrior222]

IMO in tank cleaners work for mild problems if you source the generic materials, and use like 4x the dose. i.e. a pint of mineral spirits and IPA mixed up instead of ~4 ounces, and run that tank hard.

[thefitisgay]

i think its my injectors considering i plugged one into my air compressor with some fluid in a hose infront of an air blower and im pretty positive that it wouldnt open

nless the juice in the hose was too far away

i think im gunna rig up an injector blower

[RoadWarrior222]

Use kerosene or mineral spirits in a small pressurised tank, don't put too much air pressure on it.

However, think you should have high impedance peak and hold injectors, so they might heat up just running full current. i.e. switching them on and off from a battery... could put a small resistor inline, like a spare blower motor resistor... might need to hit them on full a few times to free them up though.

[thefitisgay]

im gunna order a new set from rock auto the motocraft brand are on sale for 178/6 shipped

im worried about them being bad tho because they are factory close outs

i guess i should blpow outthe lines infront of the filter... is there an easy way to pluge a filet in between the fuel rail and connector?

[thefitisgay]

think i could raise my fuel pressure a bit to get better gas mileage?

the computer should pick up on it and work around it right?

[RoadWarrior222]

Ford fuel lines seem to be a bugger to do anything custom to, but you can probably find mustang parts/kits.

EEC will adjust "some" think you've got about 10% to play with. Mileage will likely be worse the first tank though.

[wallace]

Have you checked the sensor in the intake manifold? I don't remember what Ford calls it...MAT? If there's any blowby that sensor can get gummed up over time. Does this use a MAF for airflow calculations instead of a MAP?

[RoadWarrior222]

They're MAP on that one, but still a good idea to check the vac lines/intake for oil or fuel and confirm the PCV is fully functional.

[thefitisgay]

lol 11 mpg with the ac off how much worse cna it get??

i checked the map today by puting a different one on from my other truck that has 40k on it and nothing changed

i think its reading temp correctly since it runs at like 14.5 till it starts getting hot then it lean creeps


i wanna turbo this pig.... cut off the exhaust manifolds flange them twin stock garretts drill the intake to run 12 stock injectors cuz they are ----ing tiny and then i can retain fuel economy.... chipped computer for a mustang i guess

the intake even has twin nozzles.... its like ----ing begging for it man

---------- Post added at 11:28 AM ---------- Previous post was at 11:24 AM ----------

couldnt i even set up a safety relay hooked up to the wideband so when it goes to lean it can kick on the second set of injectors?

seems like if it wasthat easy we would have them by now...

[thefitisgay]

EGR delete or keep???

[RoadWarrior222]

For mileage, keep and/or make it bigger, reduces pumping loss in vacuum.

[thefitisgay]

so like port it?

i was gunna delete it since its gooing up my intake

---------- Post added at 12:18 AM ---------- Previous post was at 12:17 AM ----------

so it seems like i should put bigger throttle bodies on it too

[RoadWarrior222]

If you feel like messing around. port it, try and splice a bit bigger tube to it, if not just clean it out good.

[thefitisgay]

ok so like feeding the engine exhaust is better for it because its already pressurised so the motor doesnt have to waste nergy sucking air in??