Engine revving high at idle

[dkmech]

Peugeot 106 1995 1.1 petrol injection.

For the last week its been revving really hard at idle, and not just when i start it up. After a fair amount of driving too. I thought it might be trying to warm up to decent temperature as its been a bit chilly, but i am not sure. Don't know what the exact revs are coz i don't have a rev counter, but i'd say 3-4k.

Any ideas?

[schrickvr6]

Have a look under the bonnet and see if the throttle linkage is returning to fully closed, if not lube it up with a bit of spray grease and also spray plenty down inside the throttle cable sheath, otherwise i'm not sure, but it could be something like a dodgy idle stabilisation valve. (if they have one)

[[GSV]Trig]

ICV i there is one or maybe a split in a rubber inlet pipe somewhere...

[Butuz]

Also check you havent lost any engine coolant - i had a water leak and my car revved high (2000rpm) constantly before overheating.

Butuz

[dkmech]

Right, i checked engine coolant and it did need a top up. It didn't rev high after i did it, but its 12 degrees today rather than near 0 as was in the last couple of days.

The throttle cable seems fine, i am pretty sure its not the problem as when i am driving it doesnt stick or anything.

I'll see if its the coolant after its been driven for a bit.

Cheers for your suggestions guys.

[Rave]

Might be an air leak somewhere in the induction system?

Rich :¬)

[Konan555]

Right,

Firstly, like rich says, it sounds like air leak. However, at 3-4KRpm, if nothing's fallen off you'd probably hear a large air hiss from the induction. Go round any joints in the air system and give em a quick WD40 whilst listning for a change in the idle.

If it's not that, it could be your ISCV is jammed open, take it off and give it a complete clean with carb cleaner.

You may also want to try reset your base idle.

Now I'm not sure about the speicic management on frog-mobiles, so this is the 'generic' method.

Disconnect the negative lead from your battery for a good 10-20 minutes (should reset the KAM in the ECU) This isn't 100% vital

Disconnect the wires from your ISCV and TPS

Reconnect the battery

Start the engine and adjust the idle on the throttle bodies (if you can't get the idle down to normal you've REALLY got an air leak or the ISCV is totaly jammed)

Reconnect the TPS and the ISCV one at a time, if either of these causes the idle to bounce up, there's your problem.


EDIT: I meant throttle body, I assume the 1.1 unit isn't a V8

[dkmech]

Sounds great. Although about 80% of that made as much sense to me as it would to Mr H.J. Simpson.

Its been working fine after i added some more coolant.

Thanks for taking the time for such a detailed explanation. Although a mechanical engineer I'm afraid i am not yet intimate enough with my car to do more than a change of air filter and maybe spark plugs. But big thanks none the less.

[Konan555]

Ah right,

None of that would take long to explain anyway, it's all stright forward stuff.

Just gimme a shout if you have any more problems and want to try it.

[georgejamieson]

Hi all, please help!
My sons Peugeot 1.1 has an idle problem.
I first looked at it for him when the idle seemed to be stuck at 5000rpm, this happened after we charged his flat battery and ran it for the first time.
I have changed the Idle Control Valve, and MAP sensor as well as injecting lots of cleaner into the carb. It is definately not a stciking cable and coolant level is fine.
Details of current symptons are:
Engine starts fine but goes to 1700 rpm, can then drive and when approaching a junction with clutch in the speed drops to 900rpm, perfect, but as soon as you touch the throttle again it goes back to 1700.
The car is driveable but this is annoying, and he also has his MOT in a couple of weeks so I want to sort it.
Any helpful ideas would be very welcome.

[p5-]

I had this problem with an old Toyota Carina E which I had as a stop-gap.

Symptoms I was having were:
-2500rpm in neutral
-Car trying to accelerate when slowing the car/braking at low rpms (was an automatic)

After much carb cleaning of the IACV and throttle body, it turned out that some chap before me had installed modified injector seals which were allowing more air in!

Also, try resetting the ecu. In my Toyota I could just remove a certain relay rather than pull the power altogether.