Late 500 - Rough Idle Problem
Discussion
Hi all, the idle on the beast, varies from 1,350 rpm to close to stalling.
The stepper motor was replaced a few years ago and has covered approx 900 miles. I’ve taken it out and cleaned it and the housing and it’s still the same.
Tried disconnecting it and re connecting it, but no change.
Just had the cylinder heads off and some / or all of the valves re ground in, as it was down on compression ( we thought it had blown both head gaskets after boiling up numerous times, but the gaskets were fine )
Not carried out another compression test since the heads were done, its covered about 80 miles since.
The plugs, leads etc are all recent / low miles as well.
Another / or connected fault is, that when say booting it and going into second, as you lift your foot off to change gear, it feels like the engine wants to stall, then back on the gas and it fires again.
It’s driving me mad, any suggestions ?
The stepper motor was replaced a few years ago and has covered approx 900 miles. I’ve taken it out and cleaned it and the housing and it’s still the same.
Tried disconnecting it and re connecting it, but no change.
Just had the cylinder heads off and some / or all of the valves re ground in, as it was down on compression ( we thought it had blown both head gaskets after boiling up numerous times, but the gaskets were fine )
Not carried out another compression test since the heads were done, its covered about 80 miles since.
The plugs, leads etc are all recent / low miles as well.
Another / or connected fault is, that when say booting it and going into second, as you lift your foot off to change gear, it feels like the engine wants to stall, then back on the gas and it fires again.
It’s driving me mad, any suggestions ?
Any air leaks in the plenum area will play havoc with the idle control as it alters the mixture as the stepper closes its air feed, so the engine does not behave in the way the ECU expects. This leads it to constantly play catch up with the idle control. It would have to be a big air leak however to cause the problem as you throttle off. As Steve says If you can get an even idle, disconnect the stepper (engine running) and see how it behaves.
neutral 3 said:
Don’t have access to a Rover gauge
Blitz will sell you one. Well worth having.neutral 3 said:
If it is an air leak, as Blitz says, any suggestions on where to look ?
Could be anywhere but I would start with the breather hoses that run between the flame trap on the RH rocker cover and run around to connect into 2 places on the other side of the plenum. Vacuum hoses on the RH side of the plenum. Etc.Steve
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