High idle - 2008 Atom 3

[Aterro]

Hi all,

I’m hoping for some help with a high idle on a Ariel Atom 3 (supercharged with FBW).

After a spirited drive on a hot day, I noticed my idle sitting at approx 1850rpm.

The pedal looks straight and is not bent. If I remove the TPS, the revs drop to circa 1250rpm and it starts to become abit more lumpy on idle.

I’ve had a look at throttle body and all looks visually ok with the item removed from engine.

I’m not sure where the OBD port is either, if any.

Any ideas?

[Atlarge]

Hi,

I’d defo check the odbc it’s hidden in front of the gear selector cables tight on the firewall and usually fitted with a dust cover. Failing that, I’d check for air leaks on the intake side or maybe a loose vacuum hose etc..

Hope you find something!

[Atlarge]

Also check you have coolant and make sure there are no leaks etc....

[Aterro]

Thanks!

No fault code.

No coolant leaks - I’ve never seen a minor coolant leak effect idle?

[Atlarge]

Coolant - just to check if you have some, a minor leak is not likely to be an issue if the car isn't overheating...
What's the TPS percentage look like when you move the throttle but don't have the engine running? (should see the number sweep along with the amount of pedal etc)
Worth checking to see if you can hear the throttle body motor moving smoothly? - it's possible the throttle body stepper is bad, someone else on here had a similar issue.

Other than that - take it to Ariel or a Honda garage for the once over?

[Aterro]

Hey, I’m not really sure about % as my obd tool is cheap. It says 9.8% though? Do you have a obd that you would recommend?

Throttle body is weird. If I turn ignition on, push pedal all the way down, there’s an electrical noise coming from throttle body that stays on for about 5 seconds after letting off throttle? It definitely opens and closes and is slightly open at its resting position.

[John Scherrer]

Isn't that noise just the fuel pump priming?

Probably the Throttle Position Sensor above the pedal but some have found that disconnecting the battery for about 10 minutes has reset the problem - worth a try?

[Atlarge]

[mention]Aterro[/mention] - that’s the same as mine, the throttle body motor pwm whine stays for a few seconds when the butterfly closes. That’s normal as far as I’m aware, not to be confused with the pretty loud prime from the fuel pump, it’s much more high pitched. My ODBC dongle is nothing special, just a Bluetooth dongle that connects to my phone.

If it’s nothing obvious, I’d have a word with the factory and see what they advise - interested to know how you get on!

[Aterro]

Hey all.

TPS came slightly loose, doh. All ok.

[Atlarge]

Nice - glad you got it fixed!

[flying phil]

Had a spirited drive against a 3.5R. High idle the rest of the day. Turned out I had hit the accelerator so hard it had bent the bracket. Easily fixed/