EJ18 IAC valve and TB

sammydafish · Post by **sammydafish** » Thu Jun 22, 2006 3:37 pm

so I'm putting together my new engine with EJ25 SOHC heads and intake. The IAC on the 2k+ intakes are mounted on the TB but it's a stepper motor and won't work with my ECU. I know some EJ18s had the IAC on the TB too. Question is, if I get an EJ18 TB with the IAC valve on it, will it work with my ECU (95 EJ22, Jecs OBDII ECU). My IAC looks just like any of the other Jecs ones from 92+

if it does work, anyone have one? Also, is the EJ18 TB any smaller than the 2.2 one?

sammydafish · Post by **sammydafish** » Mon Jun 26, 2006 1:34 pm

bump bump.... anyone know?

Post by **Legacy777** » Mon Jun 26, 2006 6:03 pm

Any IAC on the TB is going to use a stepper motor, rather then the older rotary designed one on the intake manifold.

Project_Legacy · Post by **Project_Legacy** » Wed Jun 28, 2006 4:34 am

my 93 ej18 motor does have the iac on the TB. not sure what a stepper motor is though.

sammydafish · Post by **sammydafish** » Wed Jun 28, 2006 1:44 pm

EJ18 is definitely not a stepper motor. It's a solenoid valve and it's on the throttle Body. It's a 3 wire one too. I know there are a few different IACs, the biggest difference between the 2 and 3 wire types. I'm assuming it would work since they are both 3 wires, not 100% sure what's different engine management wise on an EJ18 though.

Also, I don't know if the TB is actually smaller or not.

vrg3 · Post by **vrg3** » Wed Jun 28, 2006 3:00 pm

It might mostly sorta kinda work. My biggest concern is that it doesn't appear that the EJ18 IAC valve has the same completely mechanical functionality that your stock one does. The stock one has a bimetallic strip in it, past which coolant flows. This makes the valve raise idle speed on its own when cold. It looks to me like the EJ18 valve relies entirely on the ECU for this functionality. I might be wrong though.

entirelyturbo · Post by **entirelyturbo** » Wed Jun 28, 2006 3:19 pm

If I get a chance tonight, I'll look at the EJ18 I have sitting in my garage. It's from a 95 Imp.

sammydafish · Post by **sammydafish** » Thu Jun 29, 2006 1:12 pm

did you get a chance to check it out?

Project_Legacy · Post by **Project_Legacy** » Thu Jun 29, 2006 5:03 pm

i believe the throttle body is very close in terms of diameter. i dont know if they are exactly the same but ive put an ej18 stock intake on an ej22 TB and vice versa. it fit fine.

entirelyturbo · Post by **entirelyturbo** » Thu Jun 29, 2006 10:50 pm

sammydafish wrote:did you get a chance to check it out?

My apologies, I didn't. I was too busy f'ing around with the wagon. But it's going to its new home officially tonight, and I don't have anything major planned for the rest of the evening, so I should be able to do it tonight.

entirelyturbo · Post by **entirelyturbo** » Sun Jul 02, 2006 1:44 am

The EJ18 TB diameter is identical to the EJ22 TB diameter.

Sorry for the delayed response.

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EJ18 IAC valve and TB

EJ18 IAC valve and TB