first here is the previous thread: https://honda-tech.com/zerothread?id=978291

video description of problem:http://www.we-todd-did-racing....DE%3D
(right click - save as)

motor is jdm b16, with a p28 stock ecu
car starts, idles, drives fine.
vtec engages.
CEL indicates code 14 : IACV

symptoms:
- under very light constant throttle at 1,500 rpms the cars idle fluctuates. (view video)

what i did last time:
- adjusted fitv
- checked iacv then replaced iacv
- checked injectors
- traced wiring to and from iacv

what i did today:
- swapped throttle body with diffrent TPS.
- changed the fitv
- changed the injectors

what i am going to do again:
- trace the wires to and from the ecu to the iacv, i need to buy a multimeter.

what id like to do:
- try another ecu, CA6VTEC was kind enough to let me try his, however, with his ecu it would not start my car, or another friends of his car.

any ideas?

all suggestions are welcome.

 

my idle problems was related to a bad ecu. (thought it was a iacv the whole time)

try another good working ecu and see if the problem persists.

at this point from your description the only thing left to cause the problem is bad wiring or a bad ecu.

 

thanks for the reply.

ive heard if the ecu is bad it may flash random codes and or wont start your car.

when your ecu was bad was the only thing it was doing is giving you the idle problem?

 

my ecu shorted after I did the skunk2 install, i extended the wiring without disconnecting the battery.

though the ecu did start, but the idle was really low. It gave me a Code 14 which was the IACV, so I kept troubleshooting this again, and again, thinking it was the problem.

I even consulted the Helms which told me to do what your picture you posted earlier, disconnect the ecu and jump two wires to see if the iacv clicks. It did, so I knew the IACV was not at fault. When I did get a chance to borrow a different ecu, I tried it and the car worked perfectly.

If you ecu is bad, this is a good chance to get Hondata or find a P28 and chip it.

Good luck with your problem.

 

thanks alot for the post.

i am in the process of trying to get another ecu.

i want to check the wiring first and make sure everything is proper.

 

bumper

 

thanks for the link to your new thread....my car is in the shop as we speak so hopefully sometime this week ill let u know how it was fixed!

 

np, i hope they can get your car fixed without killing you on the price..

yes please def let me know what was up with it.

this is such an old problem.

 

anyone else?

 

no one?

 

under your thorttle body...there are 3 10mm bolts in a triangle, take those off and turn the backside towards you there should be a plate there with 2 8mm bolts and loosen 1 of the 8mm bolts and take the other one out, have a flathead and a phillips, push the button in and take the flathead and there's 2 notches in the plate around it, turn it to the right until u cant turn anymore, and that way you can bypass the IACV problems and it wont surge.

 

yah i already did that to the fitv, it was adjusted, and also i ended up replacing it just in case.

 

?

 

...........

 

Come on everyone....There are thousands of ppl here on honda-tech and not a single person can answer this question? This poor guy and myself have been trying to find a solution to this problem FOREVER and no luck. Someone has to know something, or tell him to try something that he hasn't tried yet. All of the master mechanics, use your brains!

i have faith in honda-tech, dont let me down damnit!

 

This may be way out in left field, but I had an IACV problem for almost 10 months. It started right after the turbo install and we couldn't figure out what it was, it was intermitent and only seemed to happen in cold weather. We'd get the IAC code once in a while, then it would go away. We checked everything and it didn't go away.

Finally on the advice of one of the members here, I reconnected the coolant hose to the TB. We had rerouted it to run a coolant line to the turbo. During the summer, everything was fine, but when it got cold the IACV was sticking and causing the fluctuating idle.

 

any luck? i should be getting my car out of the shop sometime this week

 

none here on this end.

please update when you get your car back.

 

possible intake manifold leak ? why is the check engine light flashing like that ? ... wiring problem ?

 

my 90 da is having a bad idle problem as well. normally it should idle at about 800 rpm, but now it idles from 1200 and bounces for about 1800 rpm. it does this for a while and stop and later it does the same. ive got it check out and the guy said there is no vacuum leak and the iacv tube isnt dirty. so he thinks its the IACV Motor. neone else know wat i can check or thinks its the IACV Motor?

Also neone know where i can get a IACV Motor beside the dealer?

Thanks.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Stripped Honda &raquo;</TD></TR><TR><TD CLASS="quote">possible intake manifold leak ? why is the check engine light flashing like that ? ... wiring problem ?</TD></TR></TABLE>

the manifold was taken off and put back on again to make sure no leaks.

the wiring has been checked, im stumped. i think i need to try another ecu.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bootleg R &raquo;</TD></TR><TR><TD CLASS="quote">my 90 da is having a bad idle problem as well. normally it should idle at about 800 rpm, but now it idles from 1200 and bounces for about 1800 rpm. it does this for a while and stop and later it does the same. ive got it check out and the guy said there is no vacuum leak and the iacv tube isnt dirty. so he thinks its the IACV Motor. neone else know wat i can check or thinks its the IACV Motor?

Also neone know where i can get a IACV Motor beside the dealer?

Thanks.</TD></TR></TABLE>

check the classifieds. also click on my previous thread on my first post in this thread for a diagram on how to check the iacv.

 

bump

 

ive got the same problem help
IVI what did you end up doing???

 

This is an old thread BUT maybe you are still having problems. Is you TPS adjusted correctly? The issue that you explain is exactly what happens when the TPS isn't adjusted properly.

 

I know this is old, but i had this same problem and just fixed it, try the plug you have going to your temp guage in your iacv, i had the iacv plug going there and the temp guage was registering, but only because of the iacv voltage.