1993 1.6 Many Idle Issues

Technical Area Engine, Transmission, Exhaust etc
1

Hi, I’m looking for some help with my NA6 Eunos.

I’ve been having issues with idle. When I first got the car, the idle would fluctuate a bit, but after cleaning the ISCV as best I could with it still attached to the throttle body (One of the screws rounded), it sorted itself out for a short while.

A couple months after that, a new issue popped up where it the revs would dip close to stalling and sometimes actually stalling when coming to a stop. I tried cleaning the ISCV again, which helped somewhat. It then started to drop the revs any time the car was in gear with the clutch down.

After that I decided I would try and properly look at the ISCV. I managed to get the ISCV off, and replaced it with a used one I picked up after giving it a good clean. I replaced the throttle body gasket and the ISCV gasket. All the previous idle issues seem to have disappeared, however now it idles at about 2000rpm but only after I have pressed the throttle. Until then it idles at about 1000rpm. The idle adjuster screw is all the way in. The only thing i have changed is the ISCV so I suppose that would be the logical place to start but I thought I would throw this post out there just in case I’m just running in circles here. Any ideas?

Thanks,

2

Check the clutch switch. If it looks ok, disconnect it, and see if the car behaves differently.

3

It’s possible the air valve is stuck open. If the coolant circuit that supplies it is blocked, the valve will stay open.

4

I’ll have a look into that when I next have a moment. Each time I’ve disconnected those coolant lines, I have been surprised that only a dribble of coolant comes out but coolant does at the very least make it through the ISCV but maybe not at the rate it needs to. Also annoyingly the day after I made the initial post, it kinda just fixed itself. There’s definitely something not quite right but now its idling at about 1100 cold and warm instead of 2000.

5

Just to be clear, I’m talking about the air valve not the Iscv

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6

Ah right, gotcha. I just had a quick look and one of the coolant lines was completely blocked up. I’m going to assume its not just that one coolant pipe that’s blocked either, so new coolant pipes and a proper flush has moved up the priority list.

Thank you for the help