Re: Chasing Rough idle...compression?

Posted by JWL On 2011/5/20 21:48:35

Your compression test readings look reasonable and I would think they are not cause of the rough idle. The preferred way to do a compression check is as you have done, but with all the spark plugs removed. You might try the test again. I suspect you may get slightly higher readings, due to increased cranking speed, but the percent difference relationship will probably stay the same.

Have you checked the distributor rotor, cap, and wires? What do the spark plugs look like and what is their gap? This sounds to me more like an ignition problem. The old time sequence for tuning a motor was compression, ignition, and fuel system in that order. I recommend you look at your ignition system again. Good luck and let us know what you find.

(o{I}o)