Very low idle

[Van]

Yesterday got my car back from the workshop where they worked on the issue of the engine dropping dead. They replaced a relay that could be the cause, at least during test driving it did not re-occur.

But, as I experienced returning home and making an extra detour, the idle is very low, at about 400-500rpm. It's to low to run stable, and tries to correct the revs, then drops back to 400-500rpm. This is not supposed to, it normally runs at about 800rpm, with the A/C on a bit more. The idle was ok when I brought the car in last Friday.

I talked to the workshop and I'll go there tomorrow to have it checked. They say they did not change any settings on the engine.

If one of you have any clues about the low idle and what to look for please reply so I can share the information and have the case resolved.

[cranna21]

Hi,

my 1.7 ES had a very low and massivly fluctuating idle for a while, get an old school mechanic to take the idle control valve out (its right infront of the inlet manifold) and give it a good clean out and set it up again, if that doesnt work, unplug the small connector, i forget what its for, underneath the air inlet pipe, then shove it back on, that seemed to fix mine, then what happened in my case is when you were driving at say 60mph (speed is irrelevent in this case) and you were to put the clutch in and leave it in to slow down and downs shift, the revs would drop very low and some times the car would cut out, what i found out is basically on idle it was being starved of air, next to the moving part of the throttle on top of the engine, i have no idea of the name, theres a little screw down in a hole next to it, play about with it between revving the engine, if the engine is starved while you rev it it will shake like mad and almost cut out, but just keep playing around with the screw until it stops offering to cut out, at least that all solved my problem, and it sounds like the same situation

[Van]

cranna21, thanks for your reply.
This morning I had the bad idling for most of the time, but at a few moments it seemed a little better.
Alas, when I had the car in the workshop, it ran smooth. By turning off and on I could reproduce the problem, but not as convincing as I wanted.
Anyway, the mechanic cleaned the idle control valve, and the engine ran better on idle.
I went into town and during the drive it would sometimes re-occur, though not as bad as before. But revs would get low and the engine would vibrate a bit.
I'll see that I find the plug you mentioned and inspect that.

[cranna21]

If that doesn't work try playing around with the little screw I mentioned, it's the air intake bypass

[Van]

I think I found the connector you mentioned. But, how do I disconnect it? It's secured with a metal clip or spring, and I couldn't find how to undo it.