Eball

Hi guys, I had nowhere else to turn and I'm hoping someone here can help me out. I don't feel like paying out my butt for a dealership but it may come down to it, but I'm hoping now. I got a lot of answers reading your posts. Anyhow, this may be somewhat long and confusing but I will try my best to explain my situation over the past 9 months.

Last summer my timing belt broke.. oops well you all know what happens when that occurs. So instead of redoing my current engine I bought a brand new one with all sensors on it, pretty much bolt in. Well I made sure I bought the exact same engine a 1.7 sohc vtec D17A2. so after I got the engine bolted in and fired up I've had idle problems since then. All the sensors are new like stated oem ones. Ive done idle relearns reset the pcm even put my old throttle body and sensors on to no avail. When I start my car it starts high like normal then drops down to 750 where it should be. If I tap my gas it goes from 1500-2000 constantly but then I hit my brakes and it will stop.

Thats not all, while I'm driving and come to a stop as soon as I push my clutch in the rpm's sky up to 2100 rpm's until I come to a stop then it fluctuates again, this time it doesn't always go down when i pump my brakes, but sometimes it does. I checked the brake booster, the vacuum line with the check valve in it, checked vacuum lines, sensors, but when I unplug my map it calms down and stays. So I guess my fear is that my pcm is bad. But I'm no expert.

I think I've explained it all, if there's anything else I will add more. But, I've tried everything I could search for. I hope I explained this well enough.

gearbox

iTrader: (95)

clean the IAC valve and throttle body, do the idle learn again. if that doesnt work, maybe accelerator cable is sticking or your tps sensor is bad.

https://www.civicforums.com/forums/7...e-up-mods.html

04 Honda Civic

iTrader: (2)

I know exactly what your talking about. If you let the clutch rub when your stopped do the rpms go back down? Check your tps sensor, I was reading on line that it could be that. My 1988 Sentra does the same thing..I will be driving and then come to a red light push in the clutch and my rpms will go through the roof..and they go down a bit till I assume 1500 rpms(I have no tach) and then stay there..TPS is a possible cause.. check it out there is definately a way you can check the resistance on it if you have a voltmeter. When it gets warmer I am going to check mine out.

Eball

All sensors are brand new, I put my old throttle body back on with all those sensors for giggles to see what would happen because the old engine didn't have this problem and it did the same thing. So could this be a pcm problem?

gearbox

iTrader: (95)

did you do the idle learn after replacing the throttle body? read the thread it tells you how. my idle has all sorts of problems if i just bolt on the throttle body and go. esp if its a different one than the car came with. you ALWAYS must relearn the idle anytime throttle body is removed.

Eball

Yes, I have tried the relearn several times. But I have never done it the way you are saying I will try that when I get home from work in the morning and let you know. thanks

Eball

No good still does it horribly, I went to the store today and when i pushed in my clutch it jumped to like 1900 like normal but as I was pushing that in and turning into my parking spot it shot up to like 2400 weird, I have no clue.

Does anyone know what a dealer charged for diagnosis.

Eball

Ok heres the verdict. I took it in and it read 2 codes the p0505 and p1298. since they had the eld in stock I told them to go ahead and change it. (helps to know the service advisor and tech therefore cheaper pricing). Anyhow they would have to order a new iacv, I took it in wed by fri night still no call but heres where it got good. On my way home from work I noticed the idle was settling down dramatically. It still had a little fluctuation and higher rpm's at times but nothing like it was. So I got home hurried in and printed out gearbox's diy on the idle relearn and tada! No more Idle problems.

But how did the eld mess with an idle so bad?

gearbox

iTrader: (95)

hmm interesting. never thought the eld would cause that many problems. unless maybe the iac or ecu was not seeing the correct voltage or something. at least you got it fixed.