multiple o2 codes

[zedx]

it's a 4.0 5speed

runs rough from start, intermittently runs correctly. runs like this for as much as 40 miles then runs correctly till you stop for gas again (couple hundred miles).

in the last few months I have replaced all the injectors, pressure regulator, MAF sensor, TP sensor, plugs, (most recent) plug wires, fuel filter, and coil pack.

the injectors, pressure regulator, MAF and TP were replaced because of codes and I thought I had some contaminated fuel.

the codes I am getting now say that both o2 sensors are reading lean and rich. any ideas on where I should start looking?
I have checked the plugs and they are normal. I replaced the coil pack because it had too many ohms across plug to plug.

 

[04 EDGE]

sounds like you have a vacuum leak

 

[zedx]

anyone else have an idea or is he right?

 

[MAKG]

An intermittent vacuum leak?

No, he's wrong.

It's electrical. Beyond that, ANY specifics you are going to get are guesses.

I'd check all the grounds, but this really is not a good task for a novice. Given that you have already replaced good components only due to codes (which is quite wrong), now is the time to cut your losses and go to a pro.

Replacing injectors is a VERY good sign of a newbie. They almost always outlast the truck. The $300 you must have spent on those could have gone for quite a lot of professional diagnosis.

 

[04 EDGE]

An intermittent vacuum leak?

No, he's wrong.

It's electrical. Beyond that, ANY specifics you are going to get are guesses.

I'd check all the grounds, but this really is not a good task for a novice. Given that you have already replaced good components only due to codes (which is quite wrong), now is the time to cut your losses and go to a pro.

Replacing injectors is a VERY good sign of a newbie. They almost always outlast the truck. The $300 you must have spent on those could have gone for quite a lot of professional diagnosis.

a tad vain eh

anyway, vacuum leaks can be intermittent. PCV elbows for example, they get soft and either crack at the bend or suck themselves shut. very common for fords and can be intermittent. i know this from real world experience. if its an OHV engine then more then likely the intake gaskets could be leaking, the upper and middle gasket. they get hair fractures and can sometimes close back up when the engine gets hot. seen this before also.

"cut your loss and go to a pro" hmmm seems i gave him advice, oh thats right i am state of michigan master certified and also carry 6 ASE certs. been turning wrenches for 25 years, thats longer then most of you have been breathing air!


ok all the arrogance aside, can you post all the current codes.

i have a great 3 page diag tip i found VIA alldata for ford lean/rich codes

 

[MAKG]

I'm afraid I don't see that given the description.

It goes fine until he stops for gas...the engine doesn't cool significantly at a fuel stop unless it is extremely long. It also takes more like two miles to warm up the engine, not 40. Many of the relevant electrical connections are separated from the engine, so one can have very different thermal (and vibrational) effects. And HOW do you explain a rich code from a vacuum leak?

By "go to a pro," I simply did NOT mean someone who would diagnose a vehicle sight-unseen, master tech or not.

The vehicle needs a careful physical inspection. I won't pretend to know what is wrong with it without that.

And how can you rule out, say, a damp coil pack that "tracks" until it dries out? That would misfire, and flip lean codes. It wouldn't throw rich codes. But a poor body ground might....

 

[04 EDGE]

sorry not quite getting how a body ground could cause lean codes.

maybe i missed that part of the test

 

[zedx]

An intermittent vacuum leak?

No, he's wrong.

It's electrical. Beyond that, ANY specifics you are going to get are guesses.

I'd check all the grounds, but this really is not a good task for a novice. Given that you have already replaced good components only due to codes (which is quite wrong), now is the time to cut your losses and go to a pro.

Replacing injectors is a VERY good sign of a newbie. They almost always outlast the truck. The $300 you must have spent on those could have gone for quite a lot of professional diagnosis.

I replaced the injectors for the wrong reason. after figuring out that the pressure regulator was really the bad part. but the reasoning behind the injectors was that I had a cylinder that got completely filled with gas. I thought that they were pressure released instead of electronically released. thought they were weak so out they came and new ones went in.

even the pressure regulator was only giving me problems intermittently. would run fine for months then only give me problems occasionally going down the road or pulling up to stop lights/signs. 90% of the time just shutting it off and restarting would make it run right the other 10% would take a couple restarts then not show up for a while again.

 

[Power Ranger 1]

And a ground can cause a lean code if the right ground is off i am going thru the same thing my 02s are unpluged and it runs great if i plug them up it run lean as hell so that means there is a ground off some where i replaced the 02s and still get the same codes

 

[zedx]

a tad vain eh

anyway, vacuum leaks can be intermittent. PCV elbows for example, they get soft and either crack at the bend or suck themselves shut. very common for fords and can be intermittent. i know this from real world experience. if its an OHV engine then more then likely the intake gaskets could be leaking, the upper and middle gasket. they get hair fractures and can sometimes close back up when the engine gets hot. seen this before also.

"cut your loss and go to a pro" hmmm seems i gave him advice, oh thats right i am state of michigan master certified and also carry 6 ASE certs. been turning wrenches for 25 years, thats longer then most of you have been breathing air!


ok all the arrogance aside, can you post all the current codes.

i have a great 3 page diag tip i found VIA alldata for ford lean/rich codes

I only did the key on engine off test at the time. wanting to know information before I go on.

codes 172, 173,176, 177
I am using an actron code scanner. according the the chiltons one of those numbers don't exist but is in the manual for the scanner as 172, 173 for bank 1, lean then rich. bank 2 lean then rich.

 

[zedx]

I'm afraid I don't see that given the description.

It goes fine until he stops for gas...the engine doesn't cool significantly at a fuel stop unless it is extremely long. It also takes more like two miles to warm up the engine, not 40. Many of the relevant electrical connections are separated from the engine, so one can have very different thermal (and vibrational) effects. And HOW do you explain a rich code from a vacuum leak?

By "go to a pro," I simply did NOT mean someone who would diagnose a vehicle sight-unseen, master tech or not.

The vehicle needs a careful physical inspection. I won't pretend to know what is wrong with it without that.

And how can you rule out, say, a damp coil pack that "tracks" until it dries out? That would misfire, and flip lean codes. It wouldn't throw rich codes. But a poor body ground might....

I understand about not wanting to diagnose sight unseen. I work on motorcycles but not as much with FI bikes yet. I have only been working in shops about 2 years and mostly on atv's and carbed bikes.

I thought it was a spark issue so the plug wires were replaced, they didn't look that bad and didn't see any spark leaking when running (ran it in a dark garage) but was probably time with 180+K on the clock. that didn't help any so I tested the coil, it was ohming out over 2K above the 11K upper limit stated in the book so out it came and in went another.

I got a fuel pressure gauge yesterday and will be checking at lunch today.
do you know how much pressure I should be running?

the fuel stops were just long enough to put in around 15 gal of gas and maybe a pit stop. I didn't think it would be long enough for it to that much cool either. it got new intake gaskets when the injectors went in.

I may be going about some of this stuff wrong but I am not trying to cut any corners on the repairs I am doing. I don't want to have problems with it again after this is fixed. like the transmission, nothing wrong with the clutch/slave cylinder but when I replaced the trans, new parts went in so I don't have to take it apart again.

 

[MAKG]

sorry not quite getting how a body ground could cause lean codes.

maybe i missed that part of the test

OK. Here's how.

A lean code means the HEGO sensor output at the PCM reads less than 0.45V as the PCM commands a rich cycle. The HEGO sensors on many of these vehicles ground through the exhaust Y-pipe, through a ground strap, to the body (most -- and perhaps all -- of the OBD-I HEGO sensors are 3-wire types). The PCM has its own ground directly to the battery. If one of these corrodes, you get an extra voltage drop from that. This means the PCM thinks the HEGO sensor measurement is lower than it really is. If it's enough (and I've seen it), you get a lean code.

A corroded PCM ground may cause a no-start, as it also ungrounds (or underpowers) the fuel pump. Low power conditions from this within the PCM may cause some really weird drivability issues, often including many codes. A corroded body ground will generally not cause nearly as severe symptoms, as none of the critical systems depends up on it (and you can run with no functional oxygen sensor, so I'm not calling that one critical).

If the ground "floats" (i.e., it's completely gone), the behavior is dependent on inner details and can do just about anything. It will find an alternate ground path, somehow, and can flip rich or lean codes or nothing at all or (seen it....) give out of bounds and non-sensible results such as negative voltages at the PCM. A missing body ground can cause all kinds of weird behaviors on systems besides the engine, such as radios that only work when the brakes are on, and so on. A missing ground strap to the exhaust pipe can cause no other symptoms aside from the mixture-driveability problems.

I've diagnosed grounds like these with modified voltage drop tests. Measure the HEGO output on an idling fully warmed engine at the PCM (using the PCM ground), and again at the sensor (using its case ground). If they differ, find the voltage drop. If the sensor itself yields out of bounds results (<0.2V or > 1.1V), it is probably poisoned or fouled.

 

[zedx]

10psi when turn the key on, 28psi at start up while on high idle, after idle dropped it went to 28.5psi

 

[MAKG]

That's really bad.

Spec is 40 PSI KOEO, 32 PSI idle.

You say you just replaced the FPR; this would seem to indicate it's bad, or you have a leak somewhere (you would smell it).

This can flip lean codes as well -- remember, HEGO sensors measure oxygen and don't care what else is there; if the engine misfires (even by flooding it), there will be oxygen in the exhaust.

It can also have some "interesting" dynamics by interacting with cylinder temperatures.

Is there fuel in the FPR vacuum line?

 

[zedx]

That's really bad.

Spec is 40 PSI KOEO, 32 PSI idle.

You say you just replaced the FPR; this would seem to indicate it's bad, or you have a leak somewhere (you would smell it).

This can flip lean codes as well -- remember, HEGO sensors measure oxygen and don't care what else is there; if the engine misfires (even by flooding it), there will be oxygen in the exhaust.

It can also have some "interesting" dynamics by interacting with cylinder temperatures.

Is there fuel in the FPR vacuum line?

oil leaks are all I can find. I pulled that vac line off the FPR yesterday and no, there was no gas in it.

so, would a fuel pump going bad do this? that was brought up by someone I had talked to, the reason I got the tester.