Car: 94 civic ex, obd1 wired b16.
Event: Just put on ITR manifold.
What happened: Since the IAC valve from the b16 manifold would not fit on the type R manifold, i used an older one i had (which im not sure is good). Now everything seems fine, no codes at all, except the idle is surging from 1000-2500rpm.
Other things to note: Used the b16 throttle body which has a chassis mounted MAP which was fine before the ITR manifold so this seems fine. The TPS wire clip and MAP clip are correctly attached to thier respective sensors. The IAT sensor was reused from b16 manifold but the wire has some tension on it now, but seems intact.

Anyone have an suggestions/advice/answers for what this could be? Thanks

Edit: There were no problems before. All sensors, including Fast Idle and IAT were in fine working condition.


Modified by yellowfever at 1:26 AM 12/31/2003

 

youre sure you have no vacuum leaks? When we did a skunk2 manifold on a gsr motor it took a while to work the bugs out...

If you know someone with a IACV that will fit on ur manifold, try swapping it to see if it is indeed the problem. If it is, clean it really good and open it up because sometimes there is an o-ring that goes bad...cheap and easy fix if thats what is wrong.

 

Would a vac leak cause a surge? I mean whenever u take off one of the manifold vac lines in any honda (or other car) it raises the idle, but it doesnt surge. Possible air in coolant?

 

could be air in the cooling system.....although if its a newer motor..most of them came with a built in bleeder valve on the thermostat. check the manifold gasket for leaks if you didnt use some sort of sealant on it.

 

damn i have the same problem with my skunk 2 manifold on my gsr. I cant seem to find the problem either.

 

have the same problem where the idle goes anywhere from 750rpm to 1500 rpm....then I hit the throttle and it goes back down....this started after I did my AEBS intake manifold swap...

 

surging idle is common when upgrading to an ITR or Skunk2 manifold. There are ways of toning the surging idle down, but overall you're just going to have to get use to it.

things you can check:

- see if you mounted the throttlebody gasket on correctly
- make sure all 12mm manifold bolts are snug/tightened down
- make sure you route your coolant lines correctly or blocked them off accordingly and no leaks are happening. Also check to see if you have air in your cooling system (bleed cooling system). Air in the cooling system can be a culprit in a surging idle.
- adjust the throttleboy's idle adjustment screw (tighten it, turning it to the right to lower the idle).
- try resetting your ecu

 

purged coolant of all air and no change. Interestingly enough, i took off the map sensor vac line (while leaving the map clip plugged in) and the car stopped surging and did not code, although it did sound a lil funny? Any more suggestions.

 

sounds like a new iacv would benefit you and the whole world.

 

Put a ITR Throttle body on and problem solved, either it was the TPS or the Fast idle, either way, its fixed thank god.

 

Yo- **** the same issue on my b16. I got a shop to hook up a pair of skunk2 stage 1 cams - str gears, and an typeR manifold that was bored out. Now my idle goes from 700 to 1500- it calms down after it warms up - but after I hit the gas and go it starts up again. Shop states it was the cams but skunk2 told me it my cams would run stock idle. I am sitting on a typeR motor so i'mma take off the t/b and see if that fixes it.

 

Glad it's fixed, I was going to suggest the TPS.

 

Im actually learning toward Fast idle being the issue, the TPS seemed to be intact. When i open up the Fast idle ill let you know.