Hi I've got a mb4 civic that was originally a d16 auto and I've put a b16a2 manual in. I'm having idle issues and have code 14 for the iacv.
I have the p30 ecu that came with the engine but I'm using a b18c4 engine loom. I have extra plugs but none of them make any difference when plugged into the iacv or not. I've chopped one of the spare plugs off and run wires to the ecu but unsure why the a9 pin from the ecu has 2 wires coming from it on the conversion harness.

 

Same here...this is all new to me

P2E Auto ECU with D16y8 OBD2 Harness on OBD1 B18B1

Dilemma = idling at 2k; smooth not rough & engine code 14(IAC)

So far:

Started out with 6 engine codes; I'm down to 2 after addressing a few wiring/harness issues:

70 Misfire(?) STILL HAVE
10 IAT - Gone; Fix = Extended wiring/changed plug to fit temp sensor in B18 IM runner
14 IAC - STILL HAVE(See fix attempts below)
41 Primary o2 - Gone; Fix = Made o2 extension harness and used 94 Integra o2 sensor
54 CFK - Gone; Fix = ECU Harness Modification(99-00) OBD2B spliced together the 4-wires; C22/C29(cut C29 AFTER splice) & C30/C31(cut C30 AFTER splice)
65 Secondary o2 - Gone; Fix = Code disappeared when I hooked up the primary o2 ext harness

First off, swap was already in place and running with auto-to-manual conversion, I'm trying to clean it all up and clear codes. My biggest benefit is having a 94 Integra parts car sitting here and the B18B1 engine harness sitting here to ****** plugs/wiring from.

-Theres a jumper wire running across the distributor harness and it appears to be a d-series dizzy(I have an obd2 B18b dizzy sitting here but I need to figure out exactly what they cut)
-IACV setup; THEY appeared to have switched to a 2-wire plug and threw blocker in-between the IACV and IM but left the coolant flowing through
-I de-pinned the ECU Harness at B6 to B23 and removed B15

.....Still have the Code 14

The TPS sensor looks terrible and only has one screw in it. I'm also wondering if the timing is actually correct and the idle issue might come down to a tb cable linkage adjustment. I'm going to figure this out.

Lastly I have 2 P75 OBD1 ECUs & a custom 2-piece wiring harness set-up to run with OBD1. I'm only waiting on the new interface for the Civic to come in and I really liked the challenge of trying to work out this harness cause this is truly a cheap swap with a few wiring fixes if I can get these codes cleared for my own visual appeal.

To do:
-Wire up reverse lights
-Grab pinion gear from PS Integra and swap over to EJ8 PS rack
-Fab up tunnel cover from chop made for auto-to-manual conversion
-Rear disc conversion

 

Code 14, thrown immediately upon startup, means the circuit is open. First of course test the IACV itself with an ohmmeter.

The harness should have one wire of the IACV on the +12 ignition bus (yellow-black wire) and the other one going to the ECU. The conversion harness has a Y so it can work readily regardless of whether the OBDII side was wired for two-wire or three-wire IACV.

 

Thanks on the feedback, I see the black w/yellow stripe wire, black w/blue stripe wire connected to the IACV wiring. The orange wire is cut. When I jump over to the ECU harness the black w/blue stripe wire appears to be the one I de-pinned from the harness and moved from B6 to B23, I also removed the orange one from the harness.

I have 3 IACVs sitting here and I've tried two with the same results, wasn't really looking to pull the 3rd one off of my edelbrock IM just yet but oh well. What kind of resistance am I looking for at the IACV if it's G2G?

When I remove the intake and plug the bottom opening(FITV) in the TB, idle remains consistent. When I plug the top one, idle drops so I feel like it's something going on in the IAC realm. Ultimately I want to block off both and re-route the coolant but I haven't locked in on the "how-to" just yet. How long should the battery be disconnected to clear codes? I'm going off of about 15 mins

 

I think the resistance of a good two-wire IACV is about 10 ohms. Mostly you are looking for a "open" circuit (way over 100 ohms) rather than some exact resistance. You should measure this both at the valve itself and at the ECU end (with battery disconnected and ECU unplugged, but everything else plugged in). If you have continuity at the valve but not at the ECU there is a problem with the wiring.

The Y in the adapter harness is so you don't have to re-pin, the black-blue wire suitable for two wire IACV will be driven whether the OBDII system was two wire or three wire. When converting a three wire car you just don't use the orange wire.

Disconnecting the battery for less than a minute will clear the ECU. Also if the CEL does not come on while running (with the test jumper out) that means there are no code causing situations currently present. Any codes you may read would be from previous runs.

 

Copy that, I'll get some measurements a little later. I'd really just like to get rid of both the IACV/FITV and kill the engine code. I know the easiest way would be to throw in the OBD1 I have sitting but I'm going to play with it a little while longer before I swap the harness/ecu out

 

3 wire to 2 wire iacv conversion....

also the iacv is a 2 pin plug, there should only be 2 of them that are similar behind the intake manifold.