Misfire on cylinder 1-P0301 code

[smithb41]

This is a long one. I have an '02 Eclipse 2.4L with 180k miles. My timing belt broke as I was coasting through an intersection back in July. I immediately put the car in neutral and coasted to the side of the road. After I turned the engine over I could tell that the belt was broke. Got the car home and replaced both timing belts and the crankshaft sensor as that was wiped out. Put everything back together and the car started right up. Ran the motor up to 4k rpms and did not hear any knocking so I thought I hadn't done any damage to the engine.

Took the car for a spin and as soon as I would stop the car it would die. Got it back home and took it all back apart thinking that I had jumped a tooth on the timing. That was not the case. The timing marks on the crankshaft, cam, and oil sprocket were all aligned. Checked the code and had a P0301 which is cylinder 1 misfire. I've replaced all the spark plugs with NGKs. Swapped the coil pack between 1-4 and 2-3 to see if I could get a misfire on another cylinder. Still a misfire on 1. When I pull the wire off for cylinder 1 there is not a noticeable change in the idle of the car unlike if I pull the wire off of #3 cylinder. I've reset the code and run the car until it gets to normal operating temperature at idle. Once I run it up to 2500 rpms I get a misfire code on #1 again.

I've done a leak down test on all 4 cylinders and all checked out fine. My fear is that I have done damage to the valves but the leakdown test isn't showing that. The car ran fine before the busted timing belt. I've been working on this thing for a couple of weeks in the evenings so there may be other things I have tried but haven't put in here. I'm at a loss at this point. Any help would be appreciated.

 

[Honto]

A quick search shows that as being an interference motor so its time to pull the head.

 

[Hult250R]

If the leakdown test doesnt show any signs of valvetrain trouble Id be willing to bet its obviously electrical.
Id find a different coilpack from a junkyard and give that a try. Possibly a loose or grounded out wire going to the coilpack? Did you check the plug that plugs into the coilpack for frayed or cracked wires?

 

[Str8_Crazy]

Well a leak down test wont always tell you if you have a bent valve or something. Do a compression test.

 

[jpruitt546]

^^^ on the compression test

 

[Abe'sGST]

ok have you checked your injector to make sure its working properly? basic things to check for in a misfire are plugs, wires, coils and injectors...take our #1 injector, look at its wires, check its resistance to make sure its within specs, or to make it simple just change it with another injector to see if the misfire switches to that cylinder...good luck

 

[smithb41]

Thanks for the help. I had my wife help me test the compression last night. I put the booster on the car and had he crank it for 4 cycles and here are the results:

1 - 10 psi
2 - 60 psi
3 - 70 psi
4 - 50 psi

So it looks like I got some bent valves. Probably just going to scrap the car now seeing it has 180k on it. That is unless anyone knows of any other easy fix it could be?