Jonathan_ED3

I realize this is a tech/hybrid question, but since you guys are most familiar with 88-91 I'm hoping someone can help me here.

I've read not all d16a6 cars had a Fast Idle Solenoid on the back of the intake manifold, so that may be why I'm having a hard time finding any info on this.

1991 Civic Ex
OBD-OBD1 ecu conversion harness with 4 wire o2 etc (don't need to explain this part to you guys)
1999 JDM B20 using 1994 B18B intake manifold, throttle body, fuel rail, injectors etc.
We will be using a chipped OBD1 computer with a custom B20 map.

We modified the factory d16a6 engine harness to fit the B20. Lengthened oil and fan switch wires.

Everything else was a plug in using Rywire OBD0/OBD2 distributor and alternator adapters.

The only concern I have though is that the D16a6 has a "Fast Idle Solenoid" on the back of the intake manifold and ALSO an EACV.

We plugged the EACV plug from the civic harness into the IACV on the Integra intake manifold. I assume this is the correct thing to do since these solenoids do the same thing even though their names changed over the years.

But now we have an extra 2 wire plug that originally went to the "Fast Idle Solenoid" just dangling.

What do we do with this plug? Does the OBD1 ECU even look for it? Do we just leave it unplugged? Do we wire it into the EACV/IACV harness? (something I read on a 10+ year old thread, but it doesn't seem like accurate info to me)

Looking for the best advice here - this is no hack job, so please don't just reply with "you don't need it" unless I ACTUALLY don't need to do anything with it (ie B20 motor doesn't need it and the OBD1 ecu won't even look for it).

Please help guys!

Freemananana

iTrader: (3)

I want to say you are confused, but shoot I could be wrong.

The Fast Idle solenoid is actually based on engine coolant temperature. It has hoses running to it from the block. It is open at lower temps to raise the idle to help with warming up the motor. It then closes at higher temps to lower the idle down to spec.

What you have is probably something fairly important. Possible the intake air temp sensor or the IACV/EACV. It seems like you have the EACV hooked up, so I'm guessing it's the intake air temp sensor. If it went to a white looking plug on you A6 intake manifold, I am definitely right. If not, take a picture of the plug and I can offer more help.

Hope this helps.

Jonathan_ED3

I'm not good with posting pics, but if you click this link the part i'm talking about is #9 in the picture. As you can see it's not the IACV/EACV because that part is more towards the throttle body.

http://www.hondapartssales.com/lisle...H301_E0101.png

Honda calls this "Fast Idle Solenoid". If this is different from the FITV, then my mistake.

It's definitely not the IAT, because that's elsewhere on the motor for the d16a6.

I need to know what to do with the wires from the OBD0 harness that originally plugged into the "Fast Idle Solenoid" on the d16a6 because the B20 has nothing comparable.

Canadian_EF

Don't hook it up. Just leave it. It'll be fine. Remove any wiring for it from your harness. You also don't need a purge solenoid (fuel rail mounted on B series, firewall mounted for EF/CRX), or a VTEC oil pressure switch (Tap the oil pressure wire into the VTEC signal wire).

Since your new ECU won't look for that sensor/switch/solenoid or whatever, you don't need it. The ECU doesn't see it. ECU no care. Yay!

IACV is on the back of the intake manifold (2 12mm bolts)
FITV is under the throttle body on B series and most D series.

Freemananana

iTrader: (3)

I'm not really going to say too much because there are so many intake manifolds out there. But I will still try and help.

The #9 in that picture looks like the Idle Air Control Valve to me. You can see it connects to a vaccuum line to let in more air post throttle body to raise the idle of the motor or close that to lower the idle.

The FITV is the Fast Idle Thermo Valve. It should be connected to a heater hose that comes from the block, through the intake manifold, and into a chamber.

Futhermore, the FITV does not use a plug. It is heater hose operated. It has no electronic connection. So your extra harness plug cannot go to this. Could it be a knock sensor?

Here are a couple photos I found/made.

Canadian_EF

#10 is the IACV.

"FITV connects here and runs below..." that port is actually the bypass hose and connects to the thermostat housing...

#9 can be deleted. Just like the dashpot (#3), it is not required, more than likely emissions. You do not need it. Cap the port on the intake manifold.

Freemananana

iTrader: (3)

Okay, the FITV was a guess. That's sort of the area mine is connected to. I don't remember exactly.

If #10 is the IACV, is it connected on the back of the intake manifold? It has a 2 pin electrical connection. I'm not really familiar with the exact motor/intake set up he has and I was basing it off what I remember on my manifold.

Anyways, exact pictures of your set up are always better than the generic ones.

This is what I meant. I guess my explanation was poorly executed. The FITV is under the TB, the IACV is on the back of it.