Still have a missfire, help!
07-24-2016, 11:27 AM
#1
Still have a missfire, help!
I'm still having an ignition miss fire and I can't figure out what's wrong. I have replaced the following parts: Plugs, wires, distributor, coil, ICM. I have also re-routed the plug wires so that they are not touching causing the miss fire.
I'm sure the issue is with my ICM and here is why. The truck runs but has a terrible shake under load during acceleration, and is worse in 4th gear but you can feel it in all gears. IT IS NOT TRANSMISSION RELATED. I bought a BWD brand ICM from the parts store and installed on the truck and it ran great. Smooth, no miss fire, MPG went back up. Ran great for 1 month, then while I was pulling into a gas station the truck died as if I turned the key off. It would crank but would not fire. Zero spark. Returned the ICM under warranty and got another one. Same thing, ran great for 1 month then died. I put 3 of the BWD ICMs on this truck, each lasting a month and each one just dies without warning. The guys at the parts store have started hassleing me by now, claiming I have something else wrong causing them to fail, which I'm wondering if is true. But, I remember reading somewhere that people recommend the motorcraft brand parts for these trucks, so I spent the extra $80 and got the motorcraft ICM. Installed it yesterday, and it runs exactly as the truck does with the original one. Miss fire under load. So what's going on???? Why did it run fine with the cheap ones but they fail within a month, and it barely runs with the motor craft? Does anyone have an idea? I would really appreciate the help as I am out of ideas. I have a 1000 mile trip to drive home next sunday so I need my truck running by then, otherwise I don't know what I'm going to do.
I'm sure the issue is with my ICM and here is why. The truck runs but has a terrible shake under load during acceleration, and is worse in 4th gear but you can feel it in all gears. IT IS NOT TRANSMISSION RELATED. I bought a BWD brand ICM from the parts store and installed on the truck and it ran great. Smooth, no miss fire, MPG went back up. Ran great for 1 month, then while I was pulling into a gas station the truck died as if I turned the key off. It would crank but would not fire. Zero spark. Returned the ICM under warranty and got another one. Same thing, ran great for 1 month then died. I put 3 of the BWD ICMs on this truck, each lasting a month and each one just dies without warning. The guys at the parts store have started hassleing me by now, claiming I have something else wrong causing them to fail, which I'm wondering if is true. But, I remember reading somewhere that people recommend the motorcraft brand parts for these trucks, so I spent the extra $80 and got the motorcraft ICM. Installed it yesterday, and it runs exactly as the truck does with the original one. Miss fire under load. So what's going on???? Why did it run fine with the cheap ones but they fail within a month, and it barely runs with the motor craft? Does anyone have an idea? I would really appreciate the help as I am out of ideas. I have a 1000 mile trip to drive home next sunday so I need my truck running by then, otherwise I don't know what I'm going to do.
07-24-2016, 01:47 PM
#2
Went back to the store today and they tested the motor craft ICM and it passed. The guy I was working with understood my situation so he let be get the BWD brand and refunded me the difference, and I just installed it. Truck runs great again. No shudder, no miss, smooth idle.
The only thing I've noticed it do is the first 4 or 5 times you drive the truck after putting on a new ICM and doing a batt disconnect to clear the memory, when I put it in Park after driving somewhere the idle will go up and down 3 times and it will almost die, but then it steadies out. If the A/C is running, it will die. It seems like once the PCM relearns this goes away until the next time you disconnect the battery.
The only thing I've noticed it do is the first 4 or 5 times you drive the truck after putting on a new ICM and doing a batt disconnect to clear the memory, when I put it in Park after driving somewhere the idle will go up and down 3 times and it will almost die, but then it steadies out. If the A/C is running, it will die. It seems like once the PCM relearns this goes away until the next time you disconnect the battery.
07-25-2016, 09:29 PM
#4
Senior Member
Have you tried pulling the codes? Maybe the truck could tell you what's wrong.
07-26-2016, 08:55 PM
#5
07-27-2016, 08:09 AM
#7
Senior Member
Just a long shot but recently I had a misfire under load and pulled my hair out. Wire ,cap, rotor and new plugs with only few months and miles miss started. looked at everything. Finally check wires when cold they checked fine but as they got warm rechecked and found that 2 were bad. The more I drove it the miss would get worse. Replaced wires and happy now. This era of Ford computers do take time to rethink when parts are changed. Ignition parts seem to fail often nowadays so new doesn't mean these parts are good.