Boat
Probationary Member
- 1
- 0
- Feb 5, 2011
-
Rocky Hill,
Connecticut
BTW, My first post after reading on here all the time for help with other stuff i've worked on.... but im finally stuck after several hours of searching.
So, a few days ago the CEL came on when i started the car and i noticed a rough idle. While driving the engine felt rough and low on power when trying to accelerate and the CEL would blink indicating an active misfire when I wasn't engine breaking. I had a friend with a reader check it and all it gave was p0301 (cylinder 1 misfire).
I replaced the plugs first then the plug wires and neither made any difference. I used a timing gun since it was around to check spark on each of the plug wires (its just an inductive clamp) to see if it will flash the timing light and found I'm not getting spark to the first cylinder. I swapped the coil pack with a new one and still got no spark to the first cylinder which I have since returned since its expensive and its a dual coil which links cylinders 1-4 and 2-3 I should have had problems with cylinder 4 which seems fine if it was bad.
I then hooked up a test light to the 3 pin connector to the coil pack and cranked the engine and both signal wires flashed when the light was hooked up between the middle (12v?) and either signal wire so that cable seems fine.
As far as I can tell the engine computer just isn't telling the coil pack to fire the first cylinder so I'm thinking either some sensor problem, wiring, timing problem, or the PCM. For sensors the haynes manual says either the crankshaft or cam angle sensors can cause loss of spark, but I'd think it would kill the whole thing since it wont fire at all if either sensor is bad it seems. I can't find any specific wires to check that would apply only to the first cylinder either. I also have no idea how to check whether the PCM is bad, the haynes says you can't do anything with it anyway.
I've since unplugged the fuel injector for the bad cylinder so i dont kill my cat and it made no difference either (might be slightly smoother if anything) so im driving on 3 cylinders since i need to drive to class (im a college student who lives off campus).
I'm stumped and can't find anything similar in my few hours of searching everywhere for this, any ideas would be awesome, thanks!
1997 Mitsubishi Eclipse GS w/ 420A engine 151,000 miles
Burns some oil, but fine otherwise
So, a few days ago the CEL came on when i started the car and i noticed a rough idle. While driving the engine felt rough and low on power when trying to accelerate and the CEL would blink indicating an active misfire when I wasn't engine breaking. I had a friend with a reader check it and all it gave was p0301 (cylinder 1 misfire).
I replaced the plugs first then the plug wires and neither made any difference. I used a timing gun since it was around to check spark on each of the plug wires (its just an inductive clamp) to see if it will flash the timing light and found I'm not getting spark to the first cylinder. I swapped the coil pack with a new one and still got no spark to the first cylinder which I have since returned since its expensive and its a dual coil which links cylinders 1-4 and 2-3 I should have had problems with cylinder 4 which seems fine if it was bad.
I then hooked up a test light to the 3 pin connector to the coil pack and cranked the engine and both signal wires flashed when the light was hooked up between the middle (12v?) and either signal wire so that cable seems fine.
As far as I can tell the engine computer just isn't telling the coil pack to fire the first cylinder so I'm thinking either some sensor problem, wiring, timing problem, or the PCM. For sensors the haynes manual says either the crankshaft or cam angle sensors can cause loss of spark, but I'd think it would kill the whole thing since it wont fire at all if either sensor is bad it seems. I can't find any specific wires to check that would apply only to the first cylinder either. I also have no idea how to check whether the PCM is bad, the haynes says you can't do anything with it anyway.
I've since unplugged the fuel injector for the bad cylinder so i dont kill my cat and it made no difference either (might be slightly smoother if anything) so im driving on 3 cylinders since i need to drive to class (im a college student who lives off campus).
I'm stumped and can't find anything similar in my few hours of searching everywhere for this, any ideas would be awesome, thanks!
1997 Mitsubishi Eclipse GS w/ 420A engine 151,000 miles
Burns some oil, but fine otherwise
