Elise Idle problems

[Jacko123]

Hi

I've recently bought an S2 Elise (02 plate) and am having a couple of problems with it. The first thing is that its not idling very smoothly, its nothing too drastic but would still like to get it sorted. I've changed the spark plugs and cleaned the throttle body with carb cleaner but have had no joy.

I also went to use the car on Friday after it had been sat outside for a week and has now started to sometimes stall when I blip the accelerator when stationary or stuck in traffic. Could this be down to the same problem or just because it hadn't been used for a while?

There also seems to be a little bit of popping from the exhaust even after very light acceleration. I've taken the car to a garage who connected it up to a laptop to look for an error code but everything came back as normal. The car isn't misfiring or anything and drives well.

Any help to shed some light on this would be appreciated.

[odyssey2200]

have a look for any split or perished pipes on or around the intlet manifold.

[Justin S]

have you got an IACV on the inlet throttle body.This could be causing idle fluctuations. I believe mine is and hunts by about 50 rpm at tickover.

[ROB1979]

Had the same problem with mine years ago, turned out to be the engine coolant temp sensor. I cleaned out the idle speed control valve at the same time just to be sure!

I had alreay been down the spark plug and TB route so i suggest you invest in a sensor, they're only about £8 and easy to fit.

[Jacko123]

Thanks for your help.

I've cleaned the IACV with carb cleaner but it hasn't done anything so I don't know if its maybe just on its way out or if thats not the cause.

Wouldn't a faulty water coolant temp sensor have shown up as an error code when I took it into the garage?

[Justin S]

not always, sensor may just be out of calibration.I found my problem today and it was a breather from the inlet to the middle of the rocker cover had come off, so letting big gulps of air in at times causing the problem.

[ROB1979]

The sensor is used by the ECU to calculate the amount of fuel required at different engine temperatures (not the only sensor used but one of them) therefore it doesn't have to be broken to cause a problem, they can just be out of sync as someone else mentioned.

It worked for me but every problem can have a multitude of causes, good luck as it took me a while to trace it back to that, hope you get it sorted as i know how annoying it is.