Idle problem

So, ive been coming here every so often, just to kinda check on common problems with the eclipses, and now i decided to register. Anyway, onto the problem.


Ever since I bought my 98 eclipse RS 5speed, Ive been very busy and had planned on doing most of the work myself. Well, the sudden lack of a garage and a good set of tools put most of that on hold. So, currently this car is 99.9% stock.

The problem I'm experiencing is that when the car is idling, and sitting still, it will kind of "stutter" every now and then. It also seems to be idling q bit low, around 700-900 RPM. When coasting in neutral at speed, it seems to idle a bit higher (1000-1500 RPM). The higher idle at speed might be on purpose though, to enable quicker revving.

I thought at first this might be due to the recent and sudden change of tempature (it got cold fast), but it warmed up again and it still is doing it. Not being automotive progeny, the only things I can think of replacing would be the Oxygen sensor and the spark plugs.

Anyone got any other ideas that might save me some time and money? Anyone else has this kinda problem?

So, ive been coming here every so often, just to kinda check on common problems with the eclipses, and now i decided to register. Anyway, onto the problem.


Ever since I bought my 98 eclipse RS 5speed, Ive been very busy and had planned on doing most of the work myself. Well, the sudden lack of a garage and a good set of tools put most of that on hold. So, currently this car is 99.9% stock.

The problem I'm experiencing is that when the car is idling, and sitting still, it will kind of "stutter" every now and then. It also seems to be idling q bit low, around 700-900 RPM. When coasting in neutral at speed, it seems to idle a bit higher (1000-1500 RPM). The higher idle at speed might be on purpose though, to enable quicker revving.

I thought at first this might be due to the recent and sudden change of tempature (it got cold fast), but it warmed up again and it still is doing it. Not being automotive progeny, the only things I can think of replacing would be the Oxygen sensor and the spark plugs.

Anyone got any other ideas that might save me some time and money? Anyone else has this kinda problem?

well, wellcome to the forum, and about the idle, my rs idles arround 750 wich i think is the stock setting, and when coasting in neutral it idles a little higher too and utill i come to a complete stop it goes down to 750 +/-

Your ISC Motor it out

That's what the turbo models do, and it's the exact same symptoms anyway

OK... so maybe the ISC motoris bad. Is this repairable? Need to replace? Should i Try the spark plugs first?

I see nothing wrong with your idle. Mine usually idles just above the 750 rpm mark on my tach when warm. It will fluctuate slightly from time to time, but usually sits right in there.

I would say pull your plugs and make sure they are gapped correctly (.045"-.05"), and that they are still in decent shape. All that will cost you is about 15 mins. of your time.

So, ive been coming here every so often, just to kinda check on common problems with the eclipses, and now i decided to register. Anyway, onto the problem.


Ever since I bought my 98 eclipse RS 5speed, Ive been very busy and had planned on doing most of the work myself. Well, the sudden lack of a garage and a good set of tools put most of that on hold. So, currently this car is 99.9% stock.

The problem I'm experiencing is that when the car is idling, and sitting still, it will kind of "stutter" every now and then. It also seems to be idling q bit low, around 700-900 RPM. When coasting in neutral at speed, it seems to idle a bit higher (1000-1500 RPM). The higher idle at speed might be on purpose though, to enable quicker revving.

I thought at first this might be due to the recent and sudden change of tempature (it got cold fast), but it warmed up again and it still is doing it. Not being automotive progeny, the only things I can think of replacing would be the Oxygen sensor and the spark plugs.

Anyone got any other ideas that might save me some time and money? Anyone else has this kinda problem?

I think all Eclipse and Talon Idle around 750rpm give or take 50rpm. Before u jump to the conclusion of a bad ISC u should check out the vfaq website and the 1000 already ask question about Idle problems. There's a how to do it yourself guide to reseting the Idle speed control (it's suggested that this should be done once a year.) I hope this will help u. :)

Thanks all. I replaced the spark plugs a while back and that seemed to clear up most of the issue. The old spark plugs were getting pretty bad.

I started noticing temp fluctuations the other day. One of my radiator fans burnt out and I'm now in the process of replacing that. It looks like that when the one fan died it also stopped the other from turning on for some reason. If I unplug the one fan the other will come on.

Egad! Old thread.