Running REALLY rich
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From: Conyers
Running REALLY rich
1986 Bronco with the EFI 302. Ran good, and then I let it set for awhile. It quit running good and started running REALLY rich. Replaced the transmission, because the stock AOD was burnt up.
I get codes 12, 21, 22, 34,42 when I run the self test. 42 says system rich, 34 is the EGR valve outta range, 22 is MAP outta range, 21 is Engine Coolant Temp outta range, and 12 is Cannot control RPM during ER Self-Test high RPM check.
I ran the codes yesterday and got TPS out of range, so I replaced that and no improvement. I also replaced the O2 sensor because it had been in there from the factory. I'm going to check the MAP and ECT in a few minutes and look for shorts...Any ideas where to look from here?
I get codes 12, 21, 22, 34,42 when I run the self test. 42 says system rich, 34 is the EGR valve outta range, 22 is MAP outta range, 21 is Engine Coolant Temp outta range, and 12 is Cannot control RPM during ER Self-Test high RPM check.
I ran the codes yesterday and got TPS out of range, so I replaced that and no improvement. I also replaced the O2 sensor because it had been in there from the factory. I'm going to check the MAP and ECT in a few minutes and look for shorts...Any ideas where to look from here?
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Joined: Jun 2002
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From: Suffolk, VA USA
Check your engine wiring harness for breaks...as I'm taking a break from right now. I've got an 86 F150 5.0 EFI that threw all sorts of different codes...found about 18 weak spots that needed repair in the original harness. Fixed those and got great improvement, and down to one engine code, but not perfect. So I picked up another harness out of an 86 Bronco that I'm totally reconditioning to install next weekend. This harness had some issues also....a common problem spot seems to be the covering they used on spots where multiple wires join together.
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Posting Guru
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From: Conyers
I can't find any breaks...new map sensor...and that only got rid of the code 12, but it still gives all other codes.
Edit...Fuel pressure is good.
Edit...Fuel pressure is good.
Last edited by wildjon300ci; May 13, 2007 at 06:29 PM.
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From: Virginia
Check for the proper voltage at all the sensors. It's unusual that all those sensors would go bad at once. They are all fed by a 5 volt supply from the computer. So if something was wrong with the supply, then all the sensors would not work.
