I'm lost at this point...
I have had an engine light for a while. The tester at auto zone says "random, 5 and 7..."
With just over 100k on the truck, I decided it had to be the plugs. I bought new ones from auto zone. The plugs I pulled out were burnt to nubs... Lol... Anyhow, the new ones are supposedly direct replacement copper plugs from Motorcraft. I have them gapped to the .040 the underside of the hood mentioned. After replacements... The same codes. P0300, p0305, p0307. #&@%! Noticeable increase in performance.
So then I looked at my coils. I obviously am not hurrying up to replace all of them... So I set out to determine which one it may be. So I pulled out and made sure I cleaned them off really well... They looked pretty good.
I moved 1 to 7, 3 to 5, 5 to 3, and 7 to 1.... As well as 1 to 8, 4 to 6, 6 to 4, and 8 to 2... Hoping that the problem will move... No such luck... The same codes. P0300, p0305, p0307. #&@%!
So then I looked at my injectors. I obviously am not hurrying up to replace all of them... So I set out to determine which one it may be. So I pulled out and made sure I cleaned them off really well... They looked pretty good.
I moved 1 to 7, 3 to 5, 5 to 3, and 7 to 1.... As well as 1 to 8, 4 to 6, 6 to 4, and 8 to 2... Hoping that the problem will move... No such luck... The same codes. P0300, p0305, p0307. #&@%!
So at this point, I have moved everything I can think of... Still the same f'n problem exists.
The Misfires are pretty inconsistent. Seems to come from cold starts. Warm starts and running normal is clean. There is no vibration or silly sounds… if it weren’t for that light, I’d never know…
The only things left…
Bad Knock Sensor, possible software update, possible bad wire to spark coil or injector.. I suspect it’s not misfiring in 2 cylinders, but 1. The cylinders are right next to each other both physically and in the firing order. They are so close, it may be hard to detect.
Specs – Stock Jeep Grand Cherokee Limited with the 4.7 Engine code “N”
Thoughts?
Kyle
I have had an engine light for a while. The tester at auto zone says "random, 5 and 7..."
With just over 100k on the truck, I decided it had to be the plugs. I bought new ones from auto zone. The plugs I pulled out were burnt to nubs... Lol... Anyhow, the new ones are supposedly direct replacement copper plugs from Motorcraft. I have them gapped to the .040 the underside of the hood mentioned. After replacements... The same codes. P0300, p0305, p0307. #&@%! Noticeable increase in performance.
So then I looked at my coils. I obviously am not hurrying up to replace all of them... So I set out to determine which one it may be. So I pulled out and made sure I cleaned them off really well... They looked pretty good.
I moved 1 to 7, 3 to 5, 5 to 3, and 7 to 1.... As well as 1 to 8, 4 to 6, 6 to 4, and 8 to 2... Hoping that the problem will move... No such luck... The same codes. P0300, p0305, p0307. #&@%!
So then I looked at my injectors. I obviously am not hurrying up to replace all of them... So I set out to determine which one it may be. So I pulled out and made sure I cleaned them off really well... They looked pretty good.
I moved 1 to 7, 3 to 5, 5 to 3, and 7 to 1.... As well as 1 to 8, 4 to 6, 6 to 4, and 8 to 2... Hoping that the problem will move... No such luck... The same codes. P0300, p0305, p0307. #&@%!
So at this point, I have moved everything I can think of... Still the same f'n problem exists.
The Misfires are pretty inconsistent. Seems to come from cold starts. Warm starts and running normal is clean. There is no vibration or silly sounds… if it weren’t for that light, I’d never know…
The only things left…
Bad Knock Sensor, possible software update, possible bad wire to spark coil or injector.. I suspect it’s not misfiring in 2 cylinders, but 1. The cylinders are right next to each other both physically and in the firing order. They are so close, it may be hard to detect.
Specs – Stock Jeep Grand Cherokee Limited with the 4.7 Engine code “N”
Thoughts?
Kyle