New wierd problem...help!

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Jul 17, 2010 | 03:56 PM

#16

JMC302

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From: NVA

I'll try that now.

Jul 17, 2010 | 04:00 PM

#17

danr1

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From: Sand Lake, MI

Quote:

Originally Posted by JMC302

I'll try that now.

Sorry yea I should have made that more clear/clear to start with.

Jul 17, 2010 | 04:32 PM

#18

ymeski56

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From: Long Beach, Calimexiforia

The most common mistake for error code scans is not bringing engine to op. temp. prior to test. 2nd would be colluding the KOEO & KOER code's into one group, not dealing w/ the KOEO's first. Then there's the little stuff concerning WOT, power steering ect....

Jul 17, 2010 | 05:01 PM

#19

JMC302

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From: NVA

I disconnected the - terminal for much longer than 5 min (did other things during the time), it cleared the memory down to KOEO 85. That code will not be going away as the entire evap system is MIA from the PO. CM was clear.

KOER was still 98, 22.

I took it for a ride around the block to ensure it was at op temp and barely made it home Same symptom as the start of this thread but much worse...it was hard starting too.

Ran codes as soon as I got back.

KOEO 22, 85
CM 22, 96
KOER 98, 22

I had a 22 back when I first got the truck and already replaced the MAP sensor and drove it without it being an issue since May. I'm having a hard tiime believing it is the culprit once again.

Jul 17, 2010 | 05:12 PM

#20

rla2005

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From: Kentucky

The stars might lie, but the numbers never do...... Since you have already replaced the MAP once I suspect the feedback signal is incorrect. You can test the MAP with a vacuum pump and a multimeter that can read frequency. Keep the MAP connected, back probe the MAP signal wires, attach the MAP to the vacuum pump, apply vacuum, watch the signal feedback. If it is in specification repeat the same routine with the multimeter attached at the PCM connector.

Use this for reference:

Ford Fuel Injection Manifold Absolute Pressure Sensor (MAP)

Ford Fuel Injection Truck Pinouts

Jul 17, 2010 | 05:54 PM

#21

danr1

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From: Sand Lake, MI

Yea ^^^^what he said, the map issue needs corrected and I'd test that system just as he outlined.

It may not have been the map sensor itself the first time, might have been a connection problem. The act of you replacing the sensor might have moved the harness wiring enough at the time to correct the problem but only temporarily.

Jul 17, 2010 | 06:00 PM

#22

JMC302

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From: NVA

Well that brings me to the limits of the tools I have available right now. Last time it was the MAP sensor it did not have this symptom. It just idled too high and ran a little rich...but if it is the harness and connecting intermittently who knows what kind of signal its getting and what the results would be.

Thanks for the help, I'll gather what I need and get back to it soon.

Jul 28, 2010 | 12:04 PM

#23

JMC302

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From: NVA

Hi everybody, thanks for the help a little over a week ago. I found the fault in the end of the wiring harness to the MAP sensor. Not having the meter to check the MAP I pulled the lines off the installed one and wedged the second one down on the fender by the vacuum reservoir cans so I could drive it around the block to warm up...codes 98 and 22 KOER were not present. The harness is bent at an extreme angle from normal and the factory retainer on the inner fender is still in place, so that narrows it down to the very end of the harness. I have cut the sheathing off that section, but cannot find any visible breaks in the wires...so that mystery is solved for now, and the truck is running its normal roughness. Time to search for an answer to my next question, or start a new thread if the search doesn't yield any answers.