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Running rough until warm

Tiny
RIVERMIKERAT
  • MECHANIC
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The fact that this one is throwing codes left and right, and often throws conflicting codes, tells me that there is either a problem with the computer or the wiring. First it's reading high on the O2 sensor, then reading low. And then it throws conflicting MAP codes. The VSS feeds the speedo.

I presume 1/4 and 2/4 mean 1 of 4 and 2 of 4?
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Sunday, August 7th, 2016 AT 4:22 PM
Tiny
JULIESMITH1
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As far as we can tell, yes that is what it means. Don't suppose you would happen to have a clue as to where in the wiring we should start to look? Would rather start there than go get a new computer if it isn't needed, that would most likely be last resort. If it does come to that, I'll be asking how to change the PROM over. Am ordering a compression tester in the morning, hope to have by tues and use asap. Time can be an issue, husband works 2nd shift.
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Sunday, August 7th, 2016 AT 5:09 PM
Tiny
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Check the connectors at the TP, MAP, O2 sensor, and ECU. See if the wires are loose. Use a multimeter to check the resistance of the wires. Check the wires by hand to feel for cracks. Check the grounds to make sure they're solid and clean.
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Monday, August 8th, 2016 AT 6:34 AM
Tiny
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Thank you, I'll tell my husband when he gets home tonight.
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Monday, August 8th, 2016 AT 11:55 AM
Tiny
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Let us know what he finds out.
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Monday, August 8th, 2016 AT 12:20 PM
Tiny
JULIESMITH1
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I will, thank you.
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Monday, August 8th, 2016 AT 12:22 PM
Tiny
JULIESMITH1
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All grounds cleaned, wires checked, seems to be good as best we can tell. Still runs like crap. Weather permitting, doing compression checks today. Ordered computer last friday, can pick up by Wednesday.
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Sunday, August 14th, 2016 AT 6:18 AM
Tiny
JULIESMITH1
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The no signal to vss is suspect to me, the speedometer was/is working. Makes me lean towards the computer being faulty.
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Sunday, August 14th, 2016 AT 6:20 AM
Tiny
KEN L
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Yep that what is sounds like, please get back to us with the results so it will help others

Best, Ken
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Monday, August 15th, 2016 AT 11:52 AM
Tiny
JULIESMITH1
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Picking up computer today, can't believe the core charge ! I believe it is located behind the glove box in our van. Can you please give me instructions on how to remove the old one and place the PROM into the new one? I'm terrified of messing things up.
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Wednesday, August 17th, 2016 AT 6:02 AM
Tiny
KEN L
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Not problem, disconnect the battery first, then locate the ecm, next disconnect the wiring connectors one at a time, remove the small metal cover and then carefully the prom. Install the prom into the new ecm and reassemble. Then reconnect the battery. Please let me know how it goes.

Best, Ken
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Wednesday, August 17th, 2016 AT 8:39 AM
Tiny
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Changed out computer today. Still didn't fix the problem ! I don't know what to do next ! ;-(
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Thursday, August 18th, 2016 AT 11:42 AM
Tiny
KEN L
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Have you checked for vacuum leaks? I would check around the throttle body using carb spray. Here is a guide that will help you.

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Car repair can be a little frustrating, but hang in there it has to be something causing it and we will find it

Best, Ken

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Thursday, August 18th, 2016 AT 11:52 AM
Tiny
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Read article, will book mark for husband. Can you come to my house please? :-) I'm getting discouraged big time. I think he may have already done something similar to this (with carb cleaner even), but not sure he did all the places mentioned there.
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Thursday, August 18th, 2016 AT 11:59 AM
Tiny
KEN L
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I wish I could come through the computer to help you. lol I am wondering if you have an intake valve that is leaking slightly as well that would cause this. I don't have a guide for a leak down test but a compression test might do the trick,, here is a guide for you

https://www.2carpros.com/articles/how-to-test-engine-compression

Best, Ken
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Thursday, August 18th, 2016 AT 3:40 PM

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