rough idle

Hello everyone, i am new to this forum but after reading the responses to peoples problems i realise there are alot of very helpfull people out there. Now my problem is with my much loved Hyundai Lantra which is a 1998, from the last mot i believe the vin suggests it is actyally an Elantra, any way if i drive any distance short or long then park up and come back to car in less than 30 minutes it revs up and down as if the choke or something is trying to kick in, any ideas i would be extremely grateful.

Hi dave,

I'm wondering if the revving is limited to when you are at idle. Does the engine go quickly to about 1200rpm then back to almost stalling?

Weird as it sounds, the past few times that that has happened to my 97 Lantra has meant that the battery either has had clogged terminals or has decided to fail very shortly therafter.

Cleaning the battery terminals has helped.

What I would also do, which I have found helpful on occasion, is to reset the ecu. Run the car up to operating speed then shut it off. Remove the ecu fuse from the fuse box behind the battery and leave it out for least 5 minutes. Replace it and start the car, allowing it to run for 3-4 minutes without touching the accelerator or brakes. This resets the fuel and ignition back to factory default curves.

Obviously, when doing a visual inspection, make sure that all the hoses, sensors and wires in the intake system are apparently ok and connected.

If this doesn't help, get thee to a spanner turner.

Have fun!

Cheers,

Andrew

Hello Trakka

Thanks for the advice i will try those tips, and thinking about it, it has started after i have had the battery disconnected so maybe there is a clue in that. Don't know which fuse to take out but will search the forum for advice, I will let you know what happens. Thanks again Dave.............

Success

I have reset the ecu by removing the fuse and so far so good the car feels really good and the idle seems to have settled down, if it happens again I will do the job on the battery. Once again thanks for your help

Cheers Dave.......................