Rev surging

[batman]

I have an iding issue with my engine.

When the engine is warmed up & at normal operating temperature and is idling and is in gear, (either forward or reverse), with my foot on the brake it is idling are approximately 700 rpm.

Then when I take the transmission from any gear to neutral, the engine revs surge to 1,000 - 1,200 for a second or two and then settle back to 700.

Therefore, I need to wait for that 1 - 2 seconds before I re-engage and gear or a get a big clunk.

Does anyone know why this occurs ?

cheers

[ja17]

Hello Mark,

This kind of engine behavior is usually caused by a tuning issue. Make sure the engine  linkages are correct, the ignition timing is correct, and there are no engine vacuum leaks (distributor etc.). With these items checked out, a simple adjustment of fuel mixture will usually cure the issue.

If your car has the idle solenoid on the intake, or the vacuum dashpot on the intake, these items will need to be set also. This information can be found in the linkage tour and/or tech manual. Are you familiar with the spit linkage test?

[batman]

Thanks Joe. I will spend some time going through the linkage tour.