Ordering a new PCM

OK, I am out of ideas, anyone I have had look at the car is out of ideas. So about the only thing I have left to do is throw parts at this piece of shit.

Still experiencing the leaning out condition. Does it at random times, but more so at lower RPM and/or under low load. Drivers front O2 sensor will read .035v or so, indicate a lean condition, the PCM will pull fuel like crazy while the sensor is reading lean, and at the same time it will throw rich codes. Ran out of stuff to check. Checked all wiring, datalogged until I am blue in the face. Replaced the O2 sensor that is giving the flakey readings. Each time it happens, it happens for approximately 4 seconds, then snaps back to normal. It doesn't seem to happen at WOT, and I can put my tune in to an open loop condition and it won't happen. But in open loop it runs pig rich and drinks gas like I drink whiskey. I am getting less than 200 miles to a tank.

So, the only thing I have left to think of is to replace the PCM. My question is, does anyone know of anywhere to get a descent price on a PCM, and where you can order one with a specific strategy code? I can get a remanufactured PCM from ecudirect.com for $389, but they won't let me order a specific strategy code. I can order one from Ford for $899 with my specific strategy code. Or I can send mine in and have it remanufactured for $289 ( again from ecudirect ) but that means I will be without a vehicle for at least a week, maybe longer.

Reason I am wanting to order my specific strategy code is because of my tuner, and my tune. If I keep the same strategy code then I don't have to worry about virginizing my XCalII, getting over to HPP to have them rework my tune for the new strategy code, getting back, etc. Not that it is that big of a deal, but it is pretty inconvenient.

So, anyone have a hookup?


Also, anyone know where to get a PS pump for cheaper than two bills? Seems that piece of shit has decided to quit working too.

Hey Doc,
It may be worth a try to swap all 8 injectors from left to right and vice versa.
This may help narrow down your troubleshooting.

Is the rich code for bank 2 only?

A possible scenario is that you'll get one injector not spraying enough causing the bank to go lean.
The pcm increases the Fuel Pulse Width on that bank causing the other 3 to to go rich and thus the whole bank goes rich.

Peter. I have swapped injectors out the day I spent over 5 hours on the dyno trying to figure this friggin thing out. Didn't seem to make any difference. The rich code is usually for both banks. It throws 0172 and 0175 simultaneously. And like I said, it pulls fuel like mad for a good 4 seconds, then throws the code. Which makes no damn sense.

Are the O2 sensor values correct? You don't have a bad sensor do you? A new sensor for $79 may be worth a try.

Slofoot said:

Are the O2 sensor values correct? You don't have a bad sensor do you? A new sensor for $79 may be worth a try.

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Hawgman said:

Replaced the O2 sensor that is giving the flakey readings.

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Done that

What's your PCM code Doc?

thump_rrr said:

What's your PCM code Doc?

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FBJR3G5

Also, just another thing in reference to the injectors. I don't think it is an injector issue because of the very specific length of time the condition happens. Each time it occurs, it happens for almost exactly 4 seconds. If it were something mechanical such as an injector I think that it would be more random. Although I could be wrong.. hell, I have been wrong with everything I have tried so far to diagnose this.

this might be dumb.. but throwing out idea like bap issue or maybe something that can be mapped out in the tune. I thought Royb stated a map for each.. something..????? F it.. I dont know. I hope you get it hammered out soon =-(

Gutted the tune and started completely over. Same result. Also put the stock tune in and drove it around, keeping out of the boost, and had the same problem.

Hawgman said:

Drivers front O2 sensor will read .035v or so, indicate a lean condition, the PCM will pull fuel like crazy while the sensor is reading lean, and at the same time it will throw rich codes.

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Does the PCM even care what the O2 sensors are reading at WOT? Or are you talking about cruising conditions?

I did not even know you were having an issue. I had this exact same issue with my 02. I spent a ton of money trying to fix it. I was convinced it was the 02 sensors but they all were replaced and still the problem. Put it in open loop and ran fine ( race gas hehehehehe) I knew it had to be between the computer and the sensor since when you turn the sensors off it ran fine. FINALLY after a long long time I replaced the entire harness and it fixed the problem. Something went bad in the wiring but I could never find it...

s8v4o said:

Does the PCM even care what the O2 sensors are reading at WOT? Or are you talking about cruising conditions?

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Closed loop conditions under 3k RPM or so. Hell, it will do it at an idle.

GI Joe said:

I did not even know you were having an issue. I had this exact same issue with my 02. I spent a ton of money trying to fix it. I was convinced it was the 02 sensors but they all were replaced and still the problem. Put it in open loop and ran fine ( race gas hehehehehe) I knew it had to be between the computer and the sensor since when you turn the sensors off it ran fine. FINALLY after a long long time I replaced the entire harness and it fixed the problem. Something went bad in the wiring but I could never find it...

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Yea, it has been doing it for a couple of months now. Wiring harness issue huh? Interesting. I assume you are meaning just the harness for the sensor that was giving you issues, and not the entire engine compartment harness, right?

Hawgman said:

Yea, it has been doing it for a couple of months now. Wiring harness issue huh? Interesting. I assume you are meaning just the harness for the sensor that was giving you issues, and not the entire engine compartment harness, right?

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I could not find it in the part running to the sensor although I checked it good to make sure it had not burned on the exhaust...I had to buy a complete engine harness where it connects under the hood

maybe you could get someone to turn your PATS system off in your tune while you swap a couple buddies pcm's in to see if it runs right ( assuming your mods will allow that).
The sporadic nature of the problem makes it sound like a wiring issue to me...

I don't think my mods would allow it. And of the people I know that would go for that and are at least blown, they have auto cars.

Dude, I hope you get everything worked out with this. So did Manny conclude that the PCM was it, a possibility, or is that your doing? I have no knowledge what so ever about this stuff but I know you'll get it figured out.

I haven't talked to Manny since the day he spent 5 hours jacking with it. Not that I haven't "tried" to talk to him. But you know what it is like getting him on the phone.

Have you tried swaping 02's from left and right banks?