bambbrose

I've had this problem all weekend and have been trying to figure it out. I apologize for the length but I need your help badly to figure this out. I've made 2 other posts over the weekend but nobody seemed to understand the situation.

I have a 1996 dx coupe, d16y7. I put a d16y8 intake manifold on it a couple months ago, everything worked great.

This weekend I tried converting to obd1 so I can use uberdata.
I replaced the ecu with a P06, and used a JKobdconversion obd2a-obd1 harness.
I also replaced my Y7 throttle body with a Z6 throttle body, and put a Z6 2 wire IACV to work with the obd1 ecu.

I wired it up according to katmans articles on ff-squad.


Now for the problem. First, I have no CEL. It just plain idles weird. It's not like the vaccum leak idle (up and down), it's a stuttering, sounds almost like I have an agressive cam in or something. It idles around 700-800 when warm, but occasionally drops down to 550 or so (this is when the stuttering happens worst), and then brings itself back up to 800, and then repeats this process.

Now for the weird things, My IACV hum's loud as hell. Refer to videos to see what I mean. Now it hum's a little bit all the time, but it's really loud when it does the idle drop down to 550. Also, I'm just about to turbo my car, so I have a narrowband A/F gauge installed. I noticed that at idle, my gauge doesn't bounce like it used to instead it stays lean, at part throttle it bounces from lean to rich, and at WOT, it reads lean all the way. It never did this before swapping the ecu's

When I unplug the IACV while running, the engine doesn't seem to change much besides the humming going away, but when I plug it back in the humming sound is extremely loud, and the idle will jump to 1500 for 20 seconds or so and then die back down to 800.

Also when I start the car, with the engine warm, it used to jump to 1500 and then quickly settle at 700, now with the new ecu, it'll stay at 1800 or so until I tap the throttle, and then drop down to 800 and start the process stated above.

Things that I have checked:
-I tried using a different obd1 IACV, no luck, and still the same humming sound
-made sure air was bled out of coolant
-Checked the fast idle valve, and made sure the white screw was screwed in all the way
-Tried switching the 2 wires on my IACV plug, made things worse but still no CEL

Things that I can think of that I still need to check:
-try swapping out a different p06 ecu

I've almost come to the conclusion that maybe the D16y7 engine can't be run correctly on a p06 ecu. Has anybody done this sucessfully? My ecu currently isn't chipped.


I really need your help guys, I need to get my car running right so that I can install my turbo. Here are the vids:

http://parkinginlots.com/images/iacv1.AVI humming sound
http://parkinginlots.com/images/iacv2.AVI unplugging iacv
http://parkinginlots.com/images/iacv3.AVI exhaust sound
http://parkinginlots.com/images/iacv4.AVI more humming


thanks guys I appreciate any help. I need to get my car running right so I can bewst eet :P

SpankedYA!

I have a Y7 with a Y8 intake with a 2 wire IAC conversion. I also run a P06 chipped with Uberdata. The only problem I ran into was that you cant use the Y7 TB so I used the Y8. Second, My cold idle was retarded high, like 3k. I solved that by putting a piece of hose in the IAC at the front port closest to the TB to lower the orifice size. It always ran like a champ after it was warm so I can't help you there. My IAC hose trick worked awesome and the cold idle now is only 1600rpm insted of 3k. But it does work, it works well and I boost about 10 psi with no problems since. It sounds like your IAC is getting power even when your engine is at operating temp. Like you have a bad temp sensor and the computer doesn't know its warm. At operating temp the IAC should shut. I would remove it and clean it out. Mine had all sorts of carbon in it. If it cant open and close smoothly that will cause a problem. You can always try my trick and stick a plug in the first port then put the valve back on but you will have no higher cold idle. Good luck, let me know.

SpankedYA!

Also keep in mind the P06 worked well on my car stock but after I chipped it the Uberdata bin for the P06 is ---- and doesn't run for crap.

EDIT look at the second diagram down and see if this is what you did to convert to a 2 wire. http://www.turbod16.com/viewtopic.php?t=3572

bambbrose

I did use that diagram for the wiring. I moved the pin to a12 from a14. Did you ever run your car without a chipped ecu, but instead just a virgin p06? thanks for your help btw, I really appriciate your quick reply's all weekend

SpankedYA!

Yes I ran it NA and non chipped for a week. It seemed a bit lean but works.

88crxSi

my crx has the same symptoms. idles ok some of the tim eand other times drops really low and shutters and "putts".

the exhaust has the EXACT same tone. not sure about the humming though. I couldnt hear it well w/ your intake.

I have burped coolant, replaced ECU, new battery (my old one was dead, just thought i'd mention i changed this to no effect).

and i DO have an aftermarket cam, but its not very agressive.

I have a spare IACV that i'm going to clean the heck outta of it til it's like new and swap them.

i'll keep u informed.