Technical RPM drops

[Ultimatum Demon]

I have this weird problem where my rpm drops under idle and bout to stall when the engine is warm


It's supposed to idle at 1k rpm

Few years ago i noticed the gas pedal could move further up and stall the engine, so I adjusted it to not happen again and the engine stays at 1k rpm on idle.

I would send a video but don't know how

 

[eeeno]

So this thing still has a throttle cable thing and it needed to be adjusted previously. I'm not sure if you're just using it to mask another issue with the engine. However a quick fix could involve adjusting the throttle cable again.

600-800 rpm is a normal idle speed for warm engine, 1000-1100 rpm is for cold idle. So warm engine idles poorly? Well search these forums and you'll find many possible explanations. Engine being that old the reason may not be so obvious. It could be anything from worn engine to idle control valve.

 

[blu73]

1k rpm is too high for idle, should be about 750-800rpm..

When you say you adjusted the cable, it shouldn't be taught - theres meant to be a tiny bit of slack and this is probably why you could lift it slightly from idle. It shouldnt have cut out though, that suggests there is a fault somewhere. I would suspect that you have tightened the cable and now the butterfly is ever so slightly open which has raised the idle to 1k rpm and that is masking the issue. As such I'd imagine the idle control valve is sticky or not working - I would take the TB off and give it a good clean, undo your cable adjustment and go from there.

 

[Ultimatum Demon]

I got it down to 900 and it runs much better now. But I can't take it below that or else the engine will stall.
I might change the crankshaft sensor soon too.