At idle speed timing jumps 4 degrees but at higher rpm it levels out. Any ideas what could be wrong. Took it to the smog station and they where telling me its a bad valve or spark plug or plug wire, and said the timing was way off. They wanted $85 to diagnose and $1600 to repair valve. Changed the spark plugs, plug wires, dis cap, and checked the timing. Timing seems to be good at 10 deg btdc with the spout disconnected. Im wondering if they checked the timing from the right hand timing marks instead of the left side timing marks. Anyway It still has this 4 deg jump at idle. Any suggestions?

 

so is it not passing CA inspection rules I take it?

how many miles you got on it? could be a really worn timing set.

 

It has a lot of miles 270000. No it did not pass. I'm running some fuel cleaner through it know to see if this helps any, if it is a bad valve. will do a compression test later this week. Since I just bought it I dont think it has had any maintenance done to it in a long while. Is there any way to determine if the timing gears are worn. The rotor moves with out play when turning the crank.

 

Post up the data of the smog check, lets see where it failed.

 

Morning Bill here is the smog data. Visual and functional check. Failed on fuel caps (they have been replaced. Failed on ignition timing ( this I dont understand, unless it is the 4 degree jump at idle). Idle emission test results. Every thing passed except for the HC(PPM) MAX(180) GP(330) meas(1761). Failed on the meas which was way above the max. Not sure what that means. This smog was done before any tune up.