JanglinJ

I have a 2001 Honda Civic GX that is experiencing random misfires on all 4 cylinders when starting cold (temp below 40 degrees). It gets better after the car warms up and then runs fine. I've replace the spark plugs with NGK Iridium ZFR6FIX-11 which is what was originally in the car.
Three of the four coils have hairline cracks in them. I tried wrapping them with electrical tape but didn't fix the misfire on cold mornings. So I removed the electrical tape.
I've taken it to the dealer and there is low compression in Cylinder 4 (around 140 where as the other cylinders are around 120) and they keep claiming that it must be the cause of the misfire. They want to charge me a lot of money to pull the head and diagnose but I think they are trying to rip me off. Could low compression in one cylinder cause misfires on all 4 cylinders? They seem unconcerned about the cracks in the coils and claim they have checked everything that could be causing the misfire so it must be the low compression.
When I first took it to them to adjust the valves they said it was misfiring only on cylinder 3 but after the valve adjustment and the spark plug change it is misfiring on all cylinders when cold.
Any ideas?

ezone

You need a better mechanic. That engine should have 180-200+ psi compression.

ezone

Ok, let me backpedal a sec.....
Yes, low compression can be the cause of a misfire.
But your numbers aren't right. At all.
Therefore, I can't believe any of it yet.

JanglinJ

I pulled out the repair estimate and they are showing 220/220/210/150 for compression. I tested it myself and number 4 was low around 150 and the other were around 200. I didn't pay exact attention to the readings. I just wanted to confirm that number 4 was indeed low. This is the CNG Civic.

Gunner

^yes 150 is low..

ezone

Yes, the 150 is low.

Next step is to figure out WHY it is low BEFORE pulling the head off.

Cylinder leakdown test is the next step.

garibaldi209

Hey guys I also have a 2001 civic Gx with 63k miles. My car ran fine on the 50 mile commute to work this morning. At lunch I started the car which was completely cooled off in parking garage. I drove down two floors and the engine light came on and car was running rough. As soon as I parked, the car stalled. I got code p0335 crankshaft position sensor and p0302 cylinder 2 misfire. I cleared the code and drove it around the garage. It was still running rough so I parked again. This time when engine light lit up I got code P0300 Random/Multiple cylinder misfire detected, P0301, P0302, P0303 all misfiring. I have read multiple forums about all the possible problems. I need to know where to start first and trouble shooting steps. If anyone has a link or some input for troubleshooting steps that'd be really helpful. I did timing belt, water pump and tdc sensor at 60k. I was having misfire on cylinder one and miscommunication/no signal with tdc sensor before and after the timing belt service. I replaced tdc again and that problem went away. Now I'm having the 4 codes I listed first: p300, p0301, p0302, and p0303. Sorry for long post, just don't want to leave anything out.