intermittent non-firing piston

[hondo]

New plugs, new wires. But when I stand at the rear and listen to the exhaust, it sounds like this:

 

RRRRRRRRRRRRRRRR-fup-RRRRRRRRRR-fup-RRRRR-fup-RRRRRRRRR-fup

 

You get the idea. I'm thinking bad rotor/distributor at this point. Any thoughts? How does one trouble shoot this issue?

 

Thanks!

 

'92 Loyale Fuel injected 1.8L, 63K

 

http://www.brianchurilla.com

[4x4moose]

have you looked at your cap and rotor? if there is any kind of build up on the cap you can scrape it off until you get a new cap. look at the rotor and make shure that there is no damage to it, like if it came in cantact with the cap.

[Cougar]

Another easy test to do is the dollar bill test to check for a valve problem. You hold one end of the bill while you let the other end wave in the exhaust near the tailpipe. If the air from the pipe tries to suck in the bill at times then there is an exhaust valve problem.

[KStretch55]

My 91 Loyale does the same, also burns a bit of oil. I've always figured I had a leaking or burned valve and some oil leaking past the guides that caused the "fup". Any thoughts from the experts?

[azsubaru]

Just want to see where this thread goes. I have the same sound. Figured it was a burned valve, but it doesn't suck the dollar bill in at the tailpipe. Darn near everything havingto do with fuel or spark has been cleaned, rebuilt or replaced in the past couple years. Hope someone has an answer.

[KStretch55]

I'll have to try the dollar bill thing. Never thought of that. Haven't had time to do a compression test on it yet. I'm sure that will tell me too. Thought I'd do a compression check and see which cylinder is low or leaks down. Then apply air pressure to that cylinder and see if the air comes out the exhaust, intake or crankcase. That should tell me whether it's the intake valve, exhaust valve or rings.