Engine dying, no idle

She's been good for months the old girl. Yes the washer pumps packed in, then later the horn and a couple of other electric niggles but nothing major. Then today made just a short trip, she was fine on the way out but on the way back, take your foot off the accelerator and she can't find idle, she just dies. Fortunately its a manual (V8 on petrol) so a bit of half clutch and heel and toeing the brake and accelerator got me home. However any clues where to even start to look?

TIA

Lost a cylinder or two?

Idle air control valve.

+1 to IACV

I thought it might be a cylinder missing when it happened but she seemed to drive smoothly enough. Will check IACV, thanks!

Cleaned up stepper motor and various little inlets and pipes around it. Tbh was a bit sooty but not terrible. Seems to have worked though, took her out for a drive, it did happen again once but seems to be behaving now. Had plugged in the Hawkeye, nothing amiss. There is however a little tin cap on top of the stepper motor housing, like a milk top and someone's punched a hole in it, presumably to pry it out at some point. I didn't have any high-temp sealant to hand but I can't imagine that's good so will have to bung it up.

Thanks again gents! :tea:

If it is on top of the plenum by the IACV...this is just a dust cover to the idle valve bypass screw....

If it is on the side of the plenum neat the IACV, then a hole in this will cause rough running or poor starting!!

The one on top is used to correctly setup bypass air while correctly setting the IACV set point.

Codument link to IACV setup etc....it is biased towards the Morgan application of the Rover V8 but it still contains some good info on how it works.

http://www.gomog.com/allmorgan/GEMS/GEMSbyPoole.pdf