repaired lots but need help

[Strat]

Hi guys this fourm has helped me lots but I'm stuck.....
I have a 92 XLT things started out with it cutting out on me replaced IAC helped for about a week , i stopped by a shop and the guy checked the fuel pressure and it was like 20lbs told me i needed a new fuel pump .... i got one and replaced it and the fuel filter plugs and oil filter ran ok for about 3 days then started the cutting out again got to looking around on here and took a look at the injectors one was busted so replaced them all another 2 or 3 days ran fine then started the chugging again found out about reading the codes so started using it for help was getting koeo 111, cm 181, 185,186 my koer are 412,172,411,538 i replaced the O2 sensor (the old was busted) and the MAF it idles fine when you step on the gas its like its not getting enough or to much gas you let off and it idles ok again i was hoping after changing the maf it would be fixed but its not i have cleared the codes many times take for test run and codes come back poss. a bad reman. MAF??????? i also found that the box my air filter is in had a bolt broken off and air was getting in without going thru filter so bolted it up and runs a little more but you have to touch pedal really light or starts dropping out again any ideas???????? thanks much ahead of time this site has been the biggest help just been at it a week and running out of ideas of what i need to do

 

[MrShorty]

To summarize: You have multiple codes pointing to a lean condition. You have a new O2 sensor, MAF, and fuel pump.

Did you ever verify that replacing the fuel pump fixed the fuel delivery issue? Diagnosing most A/F mixture codes "by the book" starts with a fuel pressure test.

From other indications (exhaust condition, spark plug condition), can you tell if it really is running lean, or if it is really running rich?

 

[Strat]

thanks for the fast reply i haven't been able to get her back in the see if the pressure is back up to par yet but noticed my battery is dropping charge fast i charged her up last night and hooked back up about 9p.m. last night and by 7 a.m. the battery gauge was down to the low end i have noticed if this thing is below the half way mark on the battery gauge she really has a hard time firing up i died in town like that yesterday got a jump and was able to get her home.the codes keep saying lean but the smell i get is telling me rich

 

[MrShorty]

If you are getting a false lean indication, that suggests something in the O2 sensor circuit. If we assume the new O2 sensor is good, that leaves something broken in the wiring between the O2 sensor and the PCM.

 

[Strat]

just got back from getting fuel pressure reading only getting 20lbs so was told to take the new one back and make them swap also found a wire shorting for the lighter so fixed that will see if battery holds its charge now also got different code on this trip now its reading 111,111,125,181,185,186 so seems like voltage to sensors dropping somewhere but the wires seems to be ok any good source for a wiring diagram

 

[Strat]

forgot to add in the first post that i have also replaced the ECM.... gonna try to rip the fuel pump out in the next couple days and swap it so hopefully that at least gets me back to diag. pressure being correct ....anything else that would cause the pressure not to be high enough have been all along the tubes and no kinks or bends ...any test for the line when i have the tank dropped? this working on cars is a new thing to me so any ideas or tip that makes it easier are sure apprec.

 

[willindsay]

forgot to add in the first post that i have also replaced the ECM.... gonna try to rip the fuel pump out in the next couple days and swap it so hopefully that at least gets me back to diag. pressure being correct ....anything else that would cause the pressure not to be high enough have been all along the tubes and no kinks or bends ...any test for the line when i have the tank dropped? this working on cars is a new thing to me so any ideas or tip that makes it easier are sure apprec.

Has the fuel filter been replaced?

 

[MrShorty]

125,181,185,186 so seems like voltage to sensors dropping somewhere but the wires seems to be ok any good source for a wiring diagram

Any or all of those codes could be triggered by the low fuel pressure. At this point, I'd probably focus on why the fuel pressure is low. I guess your technician thinks the new fuel pump has gone bad already? Certainly a possibility. Is the fuel pump getting a full 12 V when the pressure is low? or other indication of an electrical fault in the fuel pump circuit? Is fuel being returned to the tank when the pressure is low (indicating a faulty pressure regulator)?

 

[Strat]

when he checked the pressure he tested the voltage too. it checked out he did pull the vac line off the FPR and there was no change thats when he told me replace the pump again

 

[Strat]

Has the fuel filter been replaced?

filter was replaced when i did the fuel pump first time

 

[MrShorty]

he did pull the vac line off the FPR and there was no change thats when he told me replace the pump again

not what I would call a complete test of the FPR, but it is beginning to look like the pump is bad. I would probably do one more test before replacing the pump -- something to verify for sure that the FPR is staying closed. A couple of different ways:

1) Locate a "soft" section of hose in the return line and clamp it off. If the pressure jumps up, that suggests that the FPR is opening too soon. Some people don't like this option because of the risk of damaging the hose.

2) Disconnect the return line somewhere and run the pump. If the pressure stays low and nothing comes through the return line, then the regulator is probably good and the pump has failed again. Some people don't like this option because of the fire hazard with the gasoline.

Sometimes I've heard of cases where the short piece of hose from the pump to the top of the cage assembly either isn't secured tightly or the hose has a leak in it, causing it to leak inside the gas tank. The pump itself might be fine, and it just needs a new piece of hose there.

 

[Strat]

1) Locate a "soft" section of hose in the return line and clamp it off. If the pressure jumps up, that suggests that the FPR is opening too soon. Some people don't like this option because of the risk of damaging the hose.


he did that also and no rise in the pressure that was the def."change pump again"

one thing i did find when i got home and not sure what its for there was another line by the gas lines more towards the drivers door area that had a rubber hose connecting the 2 metal ones that was kinked or bent closed so i pulled it off and cut the extra rubber off with it kinked it seemed like nothing could go thru and it smelled like gas wasn't sure if it was a return line or something but thought it shouldn't have that kink in it

 

[MrShorty]

There are three lines that run from the fuel tank to the engine bay:

1) Fuel supply: From fuel tank to fuel rail through the filter. A kink in this line would cause a low pressure condition.

2) Fuel return: from FPR to fuel tank. A kink in this line would cause a high pressure condition.

3) EVAP line: from fuel tank to charcoal cannister near the radiator. Allows gasoline vapors to go to the intake to be burned rather than venting to the atmosphere. Should have no effect on the fuel system.

Other than tracing those lines, I can't think of an easy way to identify which is which.

It does appear that you have a bad pump again.

 

[Strat]

ok its the evap . line that had the rubber piece just wasn't sure what it was all about ..... gonna try to get the tank dropped today and swap the pump ... will let ya know how that goes

 

[FIND]

Why are you replacing all this stuff when you have voltage or battery issues?

Resume testing when your battery holds a charge and you know your charging system is working correctly. Your problems could be a simple as a ground fault or even just a bad ground.

 

[Strat]

replaced pump and so far it works!!!!!!!! give it a couple days and we'll know for sure
an update hit 50 miles and a 174 popped up so checked pressure again and was at 90 lbs so replaced FPR and all seems good now