Solving the rough idle issue..
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Well it idles around 1200 rpms when warmed up and at about 1500 rpms while cold... If i get on a lil bit and come to a stop it will be around 2k and than slowly go down to 1200 rpm area.. The FITV is bypassed but I didnt have an idle problem after I bypassed my last FITV, so I guess I'm curious if that has anything to do with it? I'm thinking it might be a vacuum leak, but I've checked for leaks and found nothing.. I also just replaced all the gaskets from the head up with a Master Gasket set so they're all new and it still does this idle issue...?? Cleaned out IACV as well... Engine is obd1 d16z6...
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Joined: Apr 2005
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From: 1,2,3,4 United States Marine Corps!
Doesn't bounce like a faulty FITV, but sometimes it will go up an down like 2-3 times than idle out at around 1200rpm's like usual.. It's doesn't do it constantly with the up/down rev's usually again after i get off doin about 80mph for a minute or two.. Or sometimes if i just rev it in my driveway it will do it too...
the checklist rundown
1. bypassed FITV
2. high idle approx 1100-1200 rpms constantly
3. adjusted the idle screw w/ no change as well as clocked the dizzy no change
4. runnin an obd1 z6 with an obd1 b7 MAP sensor (was told it'd be fine here on HT)
5. runnin an obd1 z6 with an obd1 b7 TPS (was told it'd be fine here on HT as well)
6. replaced all gaskets from the head up
7. checked vacuum leaks but couldn't find any
8. every now and than it will fluctuate between 1200-1800rpms for about 10-15 seconds than reside back at around 1200rpms..
the checklist rundown
1. bypassed FITV
2. high idle approx 1100-1200 rpms constantly
3. adjusted the idle screw w/ no change as well as clocked the dizzy no change
4. runnin an obd1 z6 with an obd1 b7 MAP sensor (was told it'd be fine here on HT)
5. runnin an obd1 z6 with an obd1 b7 TPS (was told it'd be fine here on HT as well)
6. replaced all gaskets from the head up
7. checked vacuum leaks but couldn't find any
8. every now and than it will fluctuate between 1200-1800rpms for about 10-15 seconds than reside back at around 1200rpms..
Last edited by JDM_SOHC; Oct 12, 2009 at 07:50 AM. Reason: cuz im illiterate
how did u bypass the FITV with a block off plate? make sure its sealed. it sounds like a small vacuum leak to me probbaly hard to detect because its a small one. maybe ur t/b flapper stuck open alil and needs backed off?
Thread Starter
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From: 1,2,3,4 United States Marine Corps!
I bypassed the FITV with a bolt/clamp in the hose going to the front side of the FITV... and I wish it was a vacuum leak that means its something rather easily fixable, i've just searched everywhere and can't find a leak...
You might want to look at the IAC and not neccesarily the IACV. I was told that alot of times these problems will arise with a malfuctioning IAC when the weather changes. Not to proclaim this as the solution, but I once had this same problem and fixed it when I replaced the IAC, it's worth getting it checked out.
Make sure your Throttle cable isn't binding, I had that problem idling high, and my cable was binding.
GL man, I hate searching for these type of problems.
GL man, I hate searching for these type of problems.
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Thread Starter
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From: 1,2,3,4 United States Marine Corps!
throttle cable is fine... and about bleeding, the way i've been doin it is just start car, take off radiator cap, an crack open bleeder, let fan cycle twice, than close it off... although sometimes i just leave the bleeder open for like an hour an just top off coolant as it goes away... but im still having coolant magically disappear, an i smell it a lil tiny bit from inside the car...
Thread Starter
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Joined: Apr 2005
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From: 1,2,3,4 United States Marine Corps!
ok well never solved this issue but managed to get a lil vid of whats happening to maybe better help you understand what its doing...
http://s21.photobucket.com/albums/b2...=VIDEO0009.flv
http://s21.photobucket.com/albums/b2...=VIDEO0009.flv
take ur intake off and place ur hand over tb and tell me what happens if it runs perfect maybe intake mini leak. and also another test for the iacv unplug it while running an see what happens . have u ever read a haynes book or have one? it has many diagnostics you can try for this i had this prob but my ek had really really bad wire harness and was all burned and crispy lol good ole ek's wire harnesses glad i wrecked it !!!
Having the same problem out of my 95 ex with B7 drop in it... Ive tried everything, leaks/timing/throttle cable/unplugging sensors ect.. Mine just idles at like 1750 and stays there it dont fluctuate besides when you hit the gas and it does it up and down like 3 times and sits back around 1700....
messed with idle screw, found 1 hole in a vaccum line replaced it im lost... read up on the article guy is posting on here that dont seem to help me a bit.. So now im searching and this was only thread i could find that had a problem somewhat like mine and seems like OP still didnt get it fixed..
anyone have any info..dont wanna make new thread when theres one already made..
messed with idle screw, found 1 hole in a vaccum line replaced it im lost... read up on the article guy is posting on here that dont seem to help me a bit.. So now im searching and this was only thread i could find that had a problem somewhat like mine and seems like OP still didnt get it fixed..
anyone have any info..dont wanna make new thread when theres one already made..
did you take you iavc off and clean it or even replace it i had that same problem with my b16 but my friend had fixed it and now its doing it again so im pretty sure thats wat it is
my sohc zc is doing the same thing and when i pulled the IACV off to clean it i found that the oring on it was all cracked and dry rotting. so check for that. im having trouble finding and oring and dont want to pay $30 for another iacv just to use the oring......
i have the same problem on my 97 d16y7 cx. idles at 1500. once in a while it bounces from 1k to 2k. then back to 1500 firm. i cleaned the iacv and gasket was good. but no luck. what are the other possibilities? timing, vaccum leak or bad iacv?


