MR2 SW20 Question...

[Seb27]

Hello,

I am currently giving my daily driver '98 MR2 mk2 n/a a bit of an overhaul before its (and my) first ever trip to Le Mans this year... but it has a problem which I can't seem to find the answer to. When its cold, when you depress the clutch, the engine speed increases instead of decreases, to just over 2k. It never used to do this. Once the engine is fully up to temp it stops doing this. Cold start sensor problem? Have ruled out throttle position sensor as surely the problem would not be effected by engine temp if so? Anyone have any experience of this on an MR2 or similar car?

After that is fixed, the new cambelt and waterpump fitted, suspension and bushes all round and new tyres... it will be perfect!

Responses would be much appreciated

Thanks

[_Al_]

Worth a quick google on "how to read MR2 ecu codes".

It could be the Throttle position sensor, if they're not set up right you get an idle at 2,000rpm. Never heard of it changing with the clutch though!

[noosh]

Mine does this occassionally and I've asked the question before but never got a fool proof answer.
Exactly the same, at cold temps with the clutch in it'll run at just under 2000rpm.
Some have said sensors but others that its normal for this car, including a local-ish garage.

Wouldn't mind knowing as well.

[Baryonyx]

Mine doesn't speed the engine up when you depress the clutch but it does idle at relatively high revs. Around 1400rmp, at a guess, then just less than 1000rpm after a couple of minutes of running. Done that since the day I got it, never bothered me. I thought it may have been programemd for that to assist in warming the engine on start up.

[TotalControl]

Baryonyx said:

Mine doesn't speed the engine up when you depress the clutch but it does idle at relatively high revs. Around 1400rmp, at a guess, then just less than 1000rpm after a couple of minutes of running. Done that since the day I got it, never bothered me. I thought it may have been programemd for that to assist in warming the engine on start up.

From what I remember, both the 3sge and gte do this. My sr20de does this too.

[samdale]

When I first start it in the morning, mine runs at around 2k. Down to just below 1k once it's warm. It's never bothered me and can't see any harm in it.

Just got to be careful when approaching a junction in the ice. Expecting engine braking in second gear and the car accelerating was rather un-nerving the first time it happened...

[Seb27]

Thanks for the replies, it definitely has a problem though as I have used it daily for 2 years and it has only just started doing this. Always idled at 2k from cold, as expected, but has never had this increasing revs problem before. Had a bit of an experiment on the way home tonight and I am now sure it is the throttle position sensor not picking up when I come off the throttle, as if you depress the clutch after you have given it no throttle, the revs do not rise once the clutch is depressed, but if you just come off the throttle and depress the clutch, they do, and if you open the throttle quite wide, then shut off and immediately depress the clutch, the revs rise more than if you open it less. It sounds as if I am a learner driver and not coming off the gas early enough when changing gear, which is not ideal when you're driving through the city with a stainless exhaust.

So I think I have answered my own question, will try and get myself a new TPS & report back!

Edited by Seb27 on Tuesday 24th January 22:32

[Red Devil]

Seb27 said:

So I think I have answered my own question, will try and get myself a new TPS & report back!

Get your current one checked before shelling out on a new one. It may simply need adjusting. While you're at get the ICV looked at as well.

The idle on my turbo suddenly shot up to 2k and refused to return to normal no matter what. It was a 'mare in traffic so I simply disconnected the plug to the ICV. This was a temporary fix until I had an opportunity to get both (TPS and ICV) checked.

A good clean of the ICV and throttle body, resetting the TPS, and plugging the ICV connector back in - job done.