Steady speed miss
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Steady speed miss
Ok, I've done a lot with automotive electronics, but this has me totally lost.
The Truck: 95 F150, original 300 motor with 325,000 miles never been rebuilt, 5 spd trans, 3:55 rear end, 4x4, 33x12.5R15 tires
The problem: When going constant speed and giving enough gas to maintain speed, the truck will "miss", starting occasionally moving to "missing" to the point where I believe it dies for a second but then re-fires due to the fact it is manual trans.
I have gotten an intermittent CEL, when I pull codes I get the code for Ignition Control Module fault/grounded. Tested the ICM on many occasions, many times, always tests good.
What I don't understand--my buddy unplugged the EGR position sensor (the 3-wire harness on the EGR itself), which obviously throws the CEL for that issue, but the truck no longer misses. I may throw in at this point, the truck has no emissions controls anymore (smog, carbon coffee can, etc), does have EGR but I have a blocking plate between the EGR and the intake manifold.
I'm leaning toward either EGR valve issue, or possibly an issue with the distributor as it does have 325,000 miles on it. I'm also suspecting the motor is giving out, likely has valves leaking, etc and am planning a motor swap with a freshly rebuilt motor. I just want to make sure the electronics are sound before swapping motors and making a huge issue to troubleshoot here. Looking for anyone's input on this mystery here.
The Truck: 95 F150, original 300 motor with 325,000 miles never been rebuilt, 5 spd trans, 3:55 rear end, 4x4, 33x12.5R15 tires
The problem: When going constant speed and giving enough gas to maintain speed, the truck will "miss", starting occasionally moving to "missing" to the point where I believe it dies for a second but then re-fires due to the fact it is manual trans.
I have gotten an intermittent CEL, when I pull codes I get the code for Ignition Control Module fault/grounded. Tested the ICM on many occasions, many times, always tests good.
What I don't understand--my buddy unplugged the EGR position sensor (the 3-wire harness on the EGR itself), which obviously throws the CEL for that issue, but the truck no longer misses. I may throw in at this point, the truck has no emissions controls anymore (smog, carbon coffee can, etc), does have EGR but I have a blocking plate between the EGR and the intake manifold.
I'm leaning toward either EGR valve issue, or possibly an issue with the distributor as it does have 325,000 miles on it. I'm also suspecting the motor is giving out, likely has valves leaking, etc and am planning a motor swap with a freshly rebuilt motor. I just want to make sure the electronics are sound before swapping motors and making a huge issue to troubleshoot here. Looking for anyone's input on this mystery here.
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mytmanfred
1987 - 1996 F150 & Larger F-Series Trucks
8
Dec 13, 2005 05:17 PM
jimarley59
1987 - 1996 F150 & Larger F-Series Trucks
7
Jan 3, 2002 11:03 PM
