Another Lean Code Mystery: P0171 & P0174

[bigcrunch]

If you suspect a vacuum leak do a smoke test... pretty simple I made a setup for around $20.

 

[PsYcHo_FrEkE]

Well, I don't know if the lean code is going to come back or not, but the I think idle issue went away. One problem down, ninety-nine more to go!

 

[PsYcHo_FrEkE]

Well, the idle problem is fixed... but the codes are back. P0171 and a pending P0174... Back to the IM gasket I guess...

 

[PsYcHo_FrEkE]

If you suspect a vacuum leak do a smoke test... pretty simple I made a setup for around $20.

Can you elaborate on your setup? I would be very interested in this.
I do already have an aquarium pump if that would be useful.

 

[bigcrunch]

What I used:
1 gallon paint bucket
baby oil (lavender)
soldering iron low watt will work
tiki torch wick
various fittings see my pics
silicone sealer
hose, one end to a pressure regulator other to engine.
pressure regulator

I had the press regulator and fittings so I did not spend $ on them.
scroll thru pics to see how its put together:
http://i307.photobucket.com/albums/nn315/bigcrunch69/SmokeTester/100_1144.jpg

To use it pour in about an inch of baby oil let the wick absorb about an hour I waited plug in the soldering iron let it heat for about five minutes then apply 1.5 lbs of air pressure not any more you'll blow out gaskets and other. Plug the other end into a vacuum fitting.

First you have to block the air intake at throttle body MAP sensor does not like the smoke on it. Block the idle air valve I took it off cut a piece of card board single layer laid it over opening matched bolt holes, cut out bolt holes laid it back on the opening bolted down the idle air valve. Also block the pcv valve hose.

 

[rnengnr]

Solder Smell

Okay, so now I have something new going on. After having the engine running at high speed for so long and coming to a sudden stop or after high revs the idle is rough... During this rough idle the headlights dim as well. Eventually it smooths out. It actually stalled on me a couple of times during my delivery route. I honestly think it's just trying not to die... Is this still along the same lines as we were discussing with the IM gaskets or should I be looking somewhere else now?! This may be unrelated but there were a couple of times I thought I smelled a faint smell of burning solder. It only lasted for a second, but I swore I smelled something... That being said I do have a sticking caliper I may have been smelling...

Here's a vid where I tried to reproduce the idle issue. It did do it a little bit. Sorry for the wind noise. The phone was sitting right by the fan...

http://www.youtube.com/watch?v=UydS6Yl8IB0

hows your battery? that smell you describe is what i smelled when my battery was croaking and couldnt store enough power to keep up w the current (amps) so the alternator was stressing and i smelled the enamel on the alternator windings....

curiously, at night the a/c at idle drops the voltage and it started to idle poorly... thinking lots of current draw headlights, tail, ac fan etc

also reconnecting a new battery required 15 minutes of driving / idling to stabilize the ecu i guess,,,, running now ,,,,, getting lean codes again that were there before the battery problem.

im watching to see what you do about the vaccum leak

keep us up to date

RN

 

[PsYcHo_FrEkE]

hows your battery? that smell you describe is what i smelled when my battery was croaking and couldnt store enough power to keep up w the current (amps) so the alternator was stressing and i smelled the enamel on the alternator windings....

curiously, at night the a/c at idle drops the voltage and it started to idle poorly... thinking lots of current draw headlights, tail, ac fan etc

also reconnecting a new battery required 15 minutes of driving / idling to stabilize the ecu i guess,,,, running now ,,,,, getting lean codes again that were there before the battery problem.

im watching to see what you do about the vaccum leak

keep us up to date

RN

I've been working so much I haven't had much time to fool with it yet. I recently replaced the battery (not long after the codes popped up). I was having to jump it off constantly. The parts store checked the old battery when I took it back and said nothing was wrong with it, but I haven't had anymore issues with the battery dying since I replaced it. The stalling issue seems to have gone away with replacing the IAC. The smell hasn't been back either. I still have to figure out the vacuum issue, though. I'm seriously leaning more and more towards the intake gasket. I had considered checking the torque on the intake bolts, but with 270,000 miles on it I don't think it's going to be that simple. In his old age my dad neglected this poor truck for so long that I'm essentially having to rebuild it from the ground up.

Also while I'm thinking about it, the service manual says that these engines use hydraulic roller tappets and non-adjustable rocker arms. It also states that the valve tappets are non-adjustable and should be repaired or replaced if they are excessively worn or noisy. I suppose that leaves out adjusting the valve lash if I replace the VC gaskets, huh? I'm surprised nobody here caught that when I mentioned it.

 

[PsYcHo_FrEkE]

[MENTION=128932]bigcrunch[/MENTION] I'm guessing you're using an air compressor for your setup?

If all you are using is 1.5lbs I'm guessing I could probably rig up something with one of these aquarium pumps I have lying around. I saw a video online of a smoke setup using a ProNeb pump (nebulizer for breathing treatments), but since these things are not cheap and my kid kinda needs his that option is out.. unless I can convince the insurance company that his is broken and that we need another one

 

[koda2000]

I've been working so much I haven't had much time to fool with it yet. I recently replaced the battery (not long after the codes popped up). I was having to jump it off constantly. The parts store checked the old battery when I took it back and said nothing was wrong with it, but I haven't had anymore issues with the battery dying since I replaced it. The stalling issue seems to have gone away with replacing the IAC. The smell hasn't been back either. I still have to figure out the vacuum issue, though. I'm seriously leaning more and more towards the intake gasket. I had considered checking the torque on the intake bolts, but with 270,000 miles on it I don't think it's going to be that simple. In his old age my dad neglected this poor truck for so long that I'm essentially having to rebuild it from the ground up.

i've bought a few batteries over the years which tested good, but would not hold a charge. i find if you ***** long enough the parts store will just give you a replacement under warranty, even if they're saying it's good. for that reason, when i worked at a parts store, i'd always replace a customers battery if they said it was bad, even if the store's tester said it was good. the one exception i made was to a loud-mouthed woman who insisted her 2nd battery was bad. i went out to the parking lot to look at her early '70's Ford redneck P/U, only to see that the battery cables were totally fried. corroded, lumpy, green and like 4 strands of wire still attached to the terminals. i politely told her that was her real problem to which she said, "how can that be? they're the cables that came with the truck!" i replied, "i'm sure they are, that's the problem" and refused to give her another battery. she was mad as hell and said she's never come back to our store again. to which i replied "good" her husband, who had accompanied her, but had remained silent until then told me that he was sorry. i felt sorry for him - he had to go home with her...

 

[swshawaii]

Couldn't agree more koda2000. Whoever came up with the phrase "the customer is always right" should be publicly stoned.

 

[rnengnr]

I've been working so much I haven't had much time to fool with it yet. I recently replaced the battery (not long after the codes popped up). I was having to jump it off constantly. The parts store checked the old battery when I took it back and said nothing was wrong with it, but I haven't had anymore issues with the battery dying since I replaced it. The stalling issue seems to have gone away with replacing the IAC. The smell hasn't been back either. I still have to figure out the vacuum issue, though. I'm seriously leaning more and more towards the intake gasket. I had considered checking the torque on the intake bolts, but with 270,000 miles on it I don't think it's going to be that simple. In his old age my dad neglected this poor truck for so long that I'm essentially having to rebuild it from the ground up.

Also while I'm thinking about it, the service manual says that these engines use hydraulic roller tappets and non-adjustable rocker arms. It also states that the valve tappets are non-adjustable and should be repaired or replaced if they are excessively worn or noisy. I suppose that leaves out adjusting the valve lash if I replace the VC gaskets, huh? I'm surprised nobody here caught that when I mentioned it.

In the explorer, I have a P1309, P0174 and P0171, which first code means I have a misfire,,,, the plugs had 125K on them so that's the thing I changed as matter of fact,,,,,,,

I used the “TOAD” PC Software on my OBD and put up the live graph for short term fuel trim bank 1 and short term fuel trim bank 2 and long term trim for both banks as well.....

this is cool

I saw that the fuel trim for both banks was up and down near 25% to 40% (40% is maximum trim) this is the computer attempting to regulate/correct the fuel air ratio based on engine parameters throttle position, fuel type, altitude etc. also means it’s not specific to one bank or one O2 sensor,,,,,,,,

So AH HA moment high fuel trim means lean that’s why I’m getting the P0171 and P0174,,,, the P1309 means misfire, and is setting because the computer is trimming all over the place to correct the lean condition and prevent misfires but cannot be more specific as to why.......

what overall issue can affect all cylinders? MAF, IAC, ...... easier yet let’s see if there is a "Vacuum Leak",,, so I started spraying starter fluid at idle on the usual suspect rubber hoses under the hood,,,,, came around to drivers side one squirt and it started to behave badly..... bingo, hit under the EGR Valve and the Live fuel trim graphs start heading toward zero.... got it under the EGR valve near the diaphragm holes and it stalls....... start it back up and reduced the amount of spray and I can hold the graph near zero and make it stall at any time by full blast spray....

I am heading to the parts store or rockauto to get a new EGR and looking forward to having a beautifully running drivetrain,,,,,

I have the graphs showing idle trims way high and dipping on the spray of starter fluid,,,,,

FYI brakleen does not work as dramatically as starter fluid for vacuum leaks.


I have the graphs of the live measurements but cant figure out how to imbed them in the post.....

 

[PsYcHo_FrEkE]

In the explorer, I have a P1309, P0174 and P0171, which first code means I have a misfire,,,, the plugs had 125K on them so that's the thing I changed as matter of fact,,,,,,,

I used the “TOAD” PC Software on my OBD and put up the live graph for short term fuel trim bank 1 and short term fuel trim bank 2 and long term trim for both banks as well.....

this is cool

I saw that the fuel trim for both banks was up and down near 25% to 40% (40% is maximum trim) this is the computer attempting to regulate/correct the fuel air ratio based on engine parameters throttle position, fuel type, altitude etc. also means it’s not specific to one bank or one O2 sensor,,,,,,,,

So AH HA moment high fuel trim means lean that’s why I’m getting the P0171 and P0174,,,, the P1309 means misfire, and is setting because the computer is trimming all over the place to correct the lean condition and prevent misfires but cannot be more specific as to why.......

what overall issue can affect all cylinders? MAF, IAC, ...... easier yet let’s see if there is a "Vacuum Leak",,, so I started spraying starter fluid at idle on the usual suspect rubber hoses under the hood,,,,, came around to drivers side one squirt and it started to behave badly..... bingo, hit under the EGR Valve and the Live fuel trim graphs start heading toward zero.... got it under the EGR valve near the diaphragm holes and it stalls....... start it back up and reduced the amount of spray and I can hold the graph near zero and make it stall at any time by full blast spray....

I am heading to the parts store or rockauto to get a new EGR and looking forward to having a beautifully running drivetrain,,,,,

I have the graphs showing idle trims way high and dipping on the spray of starter fluid,,,,,

FYI brakleen does not work as dramatically as starter fluid for vacuum leaks.


I have the graphs of the live measurements but cant figure out how to imbed them in the post.....

Happy for you that you got yours all figured out. I don't have the extra scratch to buy a program or a livedata scanner to watch my fuel trims at the moment. I've tried spraying starter fluid at everything that had a vacuum line attached to it as well as the plenum and IM. I'm not coming up as lucky as you have.

 

[PsYcHo_FrEkE]

Truck started doing something new. I've heard it a few times here and there but finally caught it today. I still haven't done anything with the gasket set because I'm not positive that's the problem..

Anyhow, there was a very loud howling noise under the hood, so I stopped the truck and listened and I was able to pin it down to the intake hose near the filter just before it stopped. I've heard this a few times since I replaced the IACV. Still not sure exactly where it's coming from, since it stopped before I could investigate further... What could cause that noise?! Perhaps the new idle air control valve is a bad part?

On a side note, after sniffing around I discovered the burning electrical smell is near the headlight switch, so it's not related to this issue. I recently replaced the headlight switch, but the other day the dash lights wouldn't come on until I played with the dimmer switch, so I'm thinking the dimmer switch is going out.

 

[PsYcHo_FrEkE]

Truck stalled again this morning. For the most part it's running well, which is what's confusing. It hasn't lost any power that I can tell and although the idle isn't perfect it's not bad, either. I finally got a few minutes to get under the hood. Pulled the TB and found that the hoses going from the charcoal canister to the TB are dry rotted, though not leaking yet. I checked them with starter fluid. I'll have to replace them soon, but they're not the cause of the problem. I did discover a very thick coating of oil on the inside of the intake and TB. There could be something clogged up causing the problem rather than a vacuum leak. Regardless of whether it's the intake gaskets causing the problem or not, it looks like I need to get in there and do some cleaning so I'll still be ordering a gasket set...

Now I just need to find the time to do the work since I'm working 2 jobs 6 days a week for the holidays

 

[swshawaii]

Originally Posted by PsYcHo_FrEkE

I did discover a very thick coating of oil on the inside of the intake and TB. There could be something clogged up causing the problem rather than a vacuum leak.

A code P0171 may mean that one or more of the following has happened:
•The MAF (Mass Air Flow) Sensor is dirty or faulty
Note: The use of "oiled" air filters may cause the MAF to become dirty if the filter is over-oiled. There is also an issue with some vehicles where the MAF sensors leak the silicone potting material used to protect the circuitry.
•There could be a vacuum leak downstream of the MAF sensor
•Possible cracked vacuum or PCV line/connection
•Faulty or stuck open PCV valve
•Failed or faulty oxygen sensor (bank 1, sensor 1)
•Sticking/plugged or failed fuel injector
•Low fuel pressure (possible plugged/dirty fuel filter!)
•Exhaust leak between engine and first oxygen sensor

Psycho- Unless I missed it, have you inspected or changed the PCV valve? Oil breather also checked?

 

[PsYcHo_FrEkE]

Psycho- Unless I missed it, have you inspected or changed the PCV valve? Oil breather also checked?

I did check the pcv valve. Oil breather? Are you referring to the line going from the oil filler neck to the intake hose? If so, then yes.

 

[PsYcHo_FrEkE]

The first new one I bought only came with a replacement paper gasket. I returned it because of the howling and the new one came with a paper one AND a rubber one. Oddly, the old IAC was also installed using 2 gaskets... I've never seen two gaskets for one part before... are both gaskets supposed to go on?!

After checking fordparts.com I'm finding the paper gasket seems to be used on the 2.3 and 3.0L and the rubber one goes on the 4.0L. Correct me if I'm wrong.

Perhaps this has been replaced before and the last person used both because they assumed that if it came with both then it must use both?!

Anyhow, I used only the rubber one and everything seems to be functioning normally. The howl went away as well. I'll have to reset the CEL and I'll let you guys know at the end of the week how it turned out if the light doesn't come back before then.

 

[PsYcHo_FrEkE]

Replaced with another BWD... The howling went away... but now the idle problem is back again (only after traveling highway speeds for a while).... Advance auto only sells the OE part as a special order, but I decided that would be the best route take before moving on to the next possible issue that could be causing the code. They said I should get it by 12/24

 

[PsYcHo_FrEkE]

Hitachi installed... The good news is that this one is serviceable! The bad news is that the CEL is back... I guess it's on to vacuum lines and gaskets... I absolutely hate throwing parts at something, but I'm out of other options since all of my troubleshooting has failed...

 

[Runnin'OnEmpty]

.......but now the idle problem is back again (only after traveling highway speeds for a while).........(

Sounds to me like the intake O-rings are hard/brittle and
leaking. Especially considering the high miles...