folks I need some help!

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Sep 11, 2009 | 11:07 AM

#16

Tom

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From: Isanti, MN

Quote:

Originally Posted by wizardsr

Not sure about the 7.3, but his is a gasser. The gassers over 8600 gvw before 05 only have OBD1 communication, not OBDII. Here's a thread that explains it better than I can. I've dealt with bad COP's before, the only way to figure out which one is bad is to buy a new one, and start swapping until the miss goes away. PITA, but the computer doesn't have the ability to determine which cylinder is misfiring, and a misfire wont turn on the check engine light. When I had a bad cop on my 2000 V10, there was no check engine light, but there was a code in the computer (dont remember what it was), but it was completely unrelated to the miss.

Good post.

I was always led to believe OBD-II vehicles had the universal connector under the dash, and that OBD-I was manufacturer specific, and that they were not compatible.

Apparently I was wrong...thanks for the correction!

Sep 11, 2009 | 11:23 AM

#17

99 SD 250

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This is a PITA I had the same thing with mine. Coil #7 was my problem. I have a mechanic friend that helped me figure it out. He said if he had his $7-8000 computer at home he could see which cyclinders were giving the pre-codes like others here have said....but we did it the old fashoined way. I sit in the truck with it in gear foot on brake and reved it up a little so it would miss real good (like power braking, well weak power braking) and he unplugged each COP till we isolated it to #7. On his suggestion I then moved that COP to cyclinder #5 (up front on drivers side) and waited for the issue to come back (moving it helped for a couple days, and I don't drive the truck every day) when it did I verified (unplugged didn't change the way it ran rough when power braking) then replaced....runs fine now, well except for the COP mounting bolt I broke, but that's another PITA with this issue IMO.

Sep 12, 2009 | 12:03 PM

#18

rebel33382

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could the knock sensor high circuit code be causing the "miss",, or is that code a result of a bad cop making it "knock"

Sep 12, 2009 | 12:08 PM

#19

bill11012

Modular motor junkie

Joined: May 2009

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From: Texas

could be either, I have never had a knock sensor give me a code.

Sep 13, 2009 | 01:31 PM

#20

rebel33382

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snapon scanner picked up the fuel pump circuit code and knock sensor, went to advance auto yesterday, ran their actron, no codes. is there a scanner out there that can pick up a bad coil on my truck? this is getting annoying

Sep 13, 2009 | 04:42 PM

#21

tjc transport

i ain't rite

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From: Marlboro Mental Hospital.

short answer??
no.
an occasional misfire from a bad coil or boot will not throw a code. you have to wait for it to get really bad, almost dead before it will throw a readable code.

Sep 13, 2009 | 05:34 PM

#22

tseekins

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From: Maine, Virginia

Quote:

Originally Posted by wizardsr

Not arguing here as I don't know a lot about this stuff, this summer I was home in Maine and helped my brother in law fix the mis in his 2000 F-350 V-10. He plugged the scan tool in under the dash and his scanner displayed that the #3 COP had failed. There seems to be an inconsistency either with how Ford built these trucks or in our stories.

http://www.obdii.com/

Tim

Sep 13, 2009 | 05:50 PM

#23

tjc transport

i ain't rite

Joined: Mar 2005

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From: Marlboro Mental Hospital.

correct Tim. if the coil dies, or hits only once in a while it will throw a code.
if it only missfires once in a while, it wlll be noticable to you, but it will not throw a code.