High Idle

[Esprit71]

Hi all,

My 89 SE has an intermittent idle problem. When the car has warmed up, I am often finding it idles at anything between 1500 - 2000 rpm. I spotted something on the LEW site that suggested it might be the thottle capsule / EBPV set up. I'd already removed the EBPV so set about removing the throttle capsule. Having done all that I found I'm still geting the same problem. If I switch the engine off and restart the idle returns to normal.

Help???!!!

[andydclements]

If the ECU detects an issue with one of its sensor it deliberately goes to a high idle so as to prevent the engine stalling. Have you run Freescan to see what error codes and / or sensor readings you are getting?

[Esprit71]

Cheers for that Andy. Wasn't aware of that. Just waiting for my freescan package to arrive so I'll check it out the asap.

[ragingfool35]

ditto on my 90SE

let me know what you find out

[waynef]

Did you ever find out what it is?

Ever since coming to rest in the middle of a corn field on Saturdays Lotus day at Castle Coombe my car is doing just that. I was going to remove the capsule but if it does nothing then i'll leave it inplace

Waynef

[Robert Crooks]

I had exactly this intermittent problem with my SE. When I say intermittent, I mean more often than not. Tried a number of things to fix it including new idle control valve, new O2 sensor. Initially seemed to be cured, but would later return. Following Bibs review of the S4s chip upgrade he did on his SE, I ordered and installed a #2 chip from PUK, and it has idled perfectly ever since. Coincidence? I don't know, but the car runs and performs better and sweeter than ever now.

[ragingfool35]

I have PUK #6 chip and still have problem

but it is def an ECU command doing it

[s4s]

When you let it stay idle for few minutes, does check engine light show up?

In my case, I break intake manifold gasket, the one that after primary injectors and attached to cylinder head, chasing GTR and F430

I got WC stage 1 turbo , PUK red race chip, and a lot more. My boost was sustained at 1.25 bar all the way from 2nd gear to 5th gear.

The gasket started breaking by one cylinder first, then idle stay around 1500-2000 rev, never come down.

Then finally the whole gasket was broken, vacuum leaked all cylinder, idle goes up to 2500 rev, check engine light show up.

IAC works at its maximum, no longer able to control the idle.

In your case, is there any vacuum leaked? Your engine might suck too much air from other sources, not from IAC.

If that is the case, your check engine light should show up, after you let it stay idle for few minutes.

I hope this will help.

Cheers/Chale

[waynef]

Checked Vacuum and all seems ok it looks like my issue is TPS Sensor as its throwing code 34 and code 22 MAP.

Its actually behaving for the moment but the fact that every so often I get the TPS hard code failure makes me think this is the culprit.

I'll let you know next weekend once new TPS is fitted.

Waynef

[DBredS4]

mine did that, it was the tps.

you know how to get the fault codes to flash to you don't you??