My cars idle is still going up and down sometimes. its not all the time but sometimes it does it. Its not the Iac valve nor the fuel filter. i did a tune up on it so its not the plugs or wires either. Does anyone else have any ideas what else it could be?
thanks

 

Gettin any codes?

 

It does say Matenience Required when i first start it up

 

Try reseting your computer.

 

how do u do that?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by r1de4life &raquo;</TD></TR><TR><TD CLASS="quote">how do u do that?</TD></TR></TABLE>

Disconnect the battery for 30 seconds and then reconnect it.

 

What motor do you have? And what ECU are you running?

The reason I ask is because I had the wrong ecu once upon a time ago - and it had the same symptoms as you're describing.

If you want to check if its the TPS or not - unplug it and see if it jumps up and down.

 

The Motor is a H22A and i think its a P13 ECU. I also think that the Ecu is chipped b/c it revs up to 8500

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by r1de4life &raquo;</TD></TR><TR><TD CLASS="quote">The Motor is a H22A and i think its a P13 ECU. I also think that the Ecu is chipped b/c it revs up to 8500</TD></TR></TABLE>

Problem solved. I almost guarantee its the ecu.
Like i said before, i was running a different ecu - and mine sometimes used to jump up and down....usually after driving hard, and then stopping.

Try borrowing someone elses p13 ecu and see if it works.

Go to the prelude fs section and see if someone is selling one.

 

I checked 2day and and it is a P13 ECU so it must be chipped cuase it reves to 8500. Will a regular P13 ECU fix my problem

 

I would assume so - chipped ecus always present problems....just get a normal p13 ecu - try to find someone on here that has one.

you should be fine after that.

 

okay thanks.also my ECU is USDM and my motor is JDM does that matter?

 

you might throw some cel's

 

Not to start a flame war but I have a chipped P13 that revs to 8500 and it’s perfect, I also know of 15 other JDM H22s with the same chip and no problems.

If you are sure you have no vacuum leaks then it’s probably a bubble in the coolant.

After my recent engine rebuilt my idle was up and down like a ****, covering the FITV didn't help. It did it for 6 weeks until last week when it finally stopped.

When the car is cold:

Make sure your ast has coolant in it
rad cap off
make sure coolant is up to the lower part of the neck
turn your heaters to max
start the car and leave it idle
leave it running 30/40 minutes (ie. so it gets to a good temperature), if you live somewhere warm then probably 20mins, its cold in the UK atm
Turn her off
Leave her cool down
Replace cap

You may also want to try covering the bottom hole of the throttle body with your thumb when the car is idling poorly.

Hope this helps.

 

Adjust the screw thingy on the FITV, or try cleanign out the IACV. Huge write ups all over HT try searching. I bet its the problem.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ds2000 &raquo;</TD></TR><TR><TD CLASS="quote">Not to start a flame war but I have a chipped P13 that revs to 8500 and it’s perfect, I also know of 15 other JDM H22s with the same chip and no problems.

If you are sure you have no vacuum leaks then it’s probably a bubble in the coolant.

After my recent engine rebuilt my idle was up and down like a ****, covering the FITV didn't help. It did it for 6 weeks until last week when it finally stopped.

When the car is cold:

Make sure your ast has coolant in it
rad cap off
make sure coolant is up to the lower part of the neck
turn your heaters to max
start the car and leave it idle
leave it running 30/40 minutes (ie. so it gets to a good temperature), if you live somewhere warm then probably 20mins, its cold in the UK atm
Turn her off
Leave her cool down
Replace cap

You may also want to try covering the bottom hole of the throttle body with your thumb when the car is idling poorly.

Hope this helps.


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First off - every motor is different. His problem is not vacuum leaks, iacv , all that bullshit - its simply the chipped ecu.

Like i said before, i was running a different ecu, and it did the same thing......

realize that his engine doesn't rev up and down ALL THE TIME.......

it does it occasionally - meaning, it can't be a mechanical problem - otherwise, it would jump up and down all the time.

Get another ecu and you should be fine.

I'm not too familiar with the bubble in the coolant thing - so i guess you can try that....won't hurt.

You guys are making this way too difficult.