Revving At Rest

[tallpaul]

Folks,

My 1.0i Yaris has an occasional problem where, when I come to a halt, the revs drop to idle, then go up to about 1500-2000rpm for a few seconds, then drop to idle again. It'll do this all day.

It does it some days, other days it's fine, but it's now started to happen more often & is really beginning to p*ss me off !

Has anyone else seen this ? Before I start changing parts at random, any ideas as to what's gone wrong ?

The dealers aren't being too helpful.

Thanks all, TP

[JustJJ]

My mate had that happen with her Ford Ka.....she took it to the dealer and they sorted it...

*shrugs.. dunno what it was tho... but yeah damned annoying

[Yaris-Nut]

Ermm .. does it only happen when you got you're a/c on?

Cos thats normal if you have.

[JustJJ]

She didnt have A/C in the car! :P

Hope you get it sorted Mate

[Storm]

Ermm .. does it only happen when you got you're a/c on?

Cos thats normal if you have.

Revving to 2k tho - seems a bit high to compensate for current draw of the aircon?

My best guess would be a dodgy air flow or engine temp sensor. Does the engine warning light come on when it's doing this?

[dave5282]

Power steering, headlights, and in some cases stereo can effect idling, along with some other things

oh and the fan in the engine bay!

Edited June 25, 2004 by dave5282

[Boro Sera]

Possibly some sensor failure in the engine.

Unfortunately, although it can be repaired quite cheaply, it costs to put the car on the diagnostic machine.

Had a sensor go on my Audi last year. The car ran on full choke all of the time. New sensor £5. Time to fit 2 minutes. Diagnosis £39.50 +vat :(

(I've probably saved more than that due to the increase in fuel economy now though.)

Rich

EDIT - you could try disconnecting the engine sensors (1 at a time) and making sure the contacts in the connectors are clean. Give them a quick squirt of WD40 and reconnect. If it's just a dodgy connection then this may well cure it.

[tallpaul]

Guys,

There's no air con in this car, but I get your line of thought.

No warning lights, no fan or suchlike happening at the same time either.

The dealer said it could be the air flow sensor, but made it clear that they didn't know for sure, so if it was changed & it didn't fix it, that 'd be my bad luck.

Don't know if it's important, but the only other thing that I've noticed is that when I stop, it drops to tickover, goes up to about 2000rpm, then as the revs drop back to tickover again the brake pedal lowers at the same time (just a fraction); just as if the vacuum servo is getting more power. Is there any link between the servo & the engine management to bring up the revs should the servo need more power ? I'll try pumping the brakes quickly (at standstill) later to see if it revs up then. It could, of course, just be a red herring. :ffs:

Cheers, TP

[Chyownster]

Mine does the same think, i sometimes revvs so low that i think its gonn astall, Wonder what it is??

[Blue84]

Mine revs up to just below 200 rpm when I start her up sometimes..but apart from that I never have any problems..I blame it on the VVT-i!

[yaris t bone]

when your engine is idles high and then low it could be the air mass sensor

faulty that causes the engine idle weird i recon it could be the air mass sensor there again my t sport idles quite low for my liking

but its ok

[Chyownster]

Ohhhh yeah!! forgot about that!! I have put a KN Filter in and it shows that it works then!!