REALLY REALLY annoying idle problem - Hyundai Performance Forums

MVTi Mark · 04-25-2003, 01:31 PM

OK, so I love my little car but recently my patience is starting to wear REALLY thin with all the problems I've had with it.

This is what is happening. When the car is idling, it starts to idle too high (upto 1500 rpm even when its warm) and slowly comes back down to normal. Then, every so often, it revs itself slowly upto 1500 rpm and drops again. Also, sometimes my vacuum drops (at normal idle it sits at about 22 but when its playing up it can drop to 15). And sometimes, when I switch the car on, it revs to 2000 rpm and then cuts out - not jerkilly, it does it very smoothly. Funny thing is, there's no lack of power, and when I'm driving it runs as smoothly as it always has - boost comes on fine, plenty of power when I need it.

Now this is where it gets wierd, I had an oil leak, and on inspection, I found a tiny hole in the sump under the oil return pipe. So, I removed the sump, cleaned it all up, and patched the hole with some specialist sump repair metal paste. I let it dry solid, followed all the guidelines then put the sump back on the car. Filled it with good new oil (used synthetic coz turbo motors like that), then got the car running again. It ran beautifully for 4 days - no idle problems, running like new. I thought that the idling problem must have been due to an oil pressure problem (coz of the hole) and that the engine was revving hard to increase the lost oil pressure. But, now I'm totally confused by it all.

I do hope someone can help. I'm not one for taking my car to mechanics coz they rip you off and I'd rather sort it myself anyways.

Oh yeah, one last thing, its also using LOADS of fuel.

Thanks in advance.........

door_man · 04-25-2003, 03:11 PM

A friend of mine had the exact same problem with idling on his civic. The problem was that alternator had a bad ground. Don't ask me what's that got to do with idling, but when he fixed it it ran perfect again. So maybe you should check if all your ground cables are ok. Hope it helps.

jerkitt · 04-25-2003, 06:05 PM

my friend's accord does that

apparently it's to "properly warm the car up"

i told him he's a moron and his car is 13 years old and he should shut up.... :??:

WytchDctr · 04-25-2003, 06:55 PM

My car does it when its cold.. idles low.. then idles a lil high.. then comes back down.. Shadohh says its it trying to warm up.. so he may not be the moron.

jerkitt · 04-25-2003, 07:07 PM

i tell him he's a moron and should shut up because it's fun to piss him off.... :hmmm:

when mine's really cold (like, middle of winnipeg winter) it idles at almost 2000, but SLOWLY slowly drops

VALKYRIE YB70 · 04-25-2003, 07:48 PM

Mark........I`m sure some of your problems are caused by dumping boost to atmosphere in a MAF-equipped car. The first thing to go is the idle.....I`m sure you must have read the results of my experiment with this, posted here recently!.
Cheers, Nick.

MVTi Mark · 04-27-2003, 03:42 PM

Nick, the atmospheric dump valve has been on the car for 12 months now without any previous problems. I know that you are not keen on using this type of valve on our cars, but this one was made for cars with MAF and the car ran exactly the same after I removed it and blocked the pipe (and reset the ECU).

It doesn't matter whether the car is warm or cold - it almost always does it now.

I just dont understand why it was ok for 4 days after I fixed the oil problem but then went back to its old tricks.

MVTi Mark · 04-28-2003, 02:09 PM

No-one else got any idea's? Oh well, good job I'm going Nissan next!!!!!!!!

Might finally get myself a car that I dont need to work on every month just to keep it on the road!!! lol

spyrosturbo · 04-29-2003, 05:07 AM

i had the same problem but my mechanic solved it by changing a part on the top of the engine "i don't know the exact name of it, but i will describe it as rpm sensor"...if you move it with your hand you will see that the rpm's will go normal again and i advice you to try it yourself before going to a mechanic.when i told my mechanic that it wasn't working properly he said that it had no problem but when i told him that when i moved that part on the engine it worked fine he changed the part although the "electronic service sensor" he used reported no damage....by that time it works fine.......don't buy a nissan our scoupe's are like a beatiful woman...they do "tricks" to us in order to love them more

MVTi Mark · 04-29-2003, 06:52 PM

Already made my mind up. Definitely going Nissan 200sx next, wont be till this time next year though.

Are you referring to the idle control valve? The one just to the right at the top of the turbo pipe near the throttle body? Thought it could be that. Anyone know a roundabout cost for a replacement? I was under the impression that they were fairly expensive to replace, although with it being a Bosch unit, it may not be Hyundai specific so........