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Custom Idle Air Control Body for use with Jeep 4.0l IAC Valve
Custom Idle Air Control Body for use with Jeep 4.0l IAC Valve
Custom Idle Air Control Body for use with Jeep 4.0l IAC Valve
Custom Idle Air Control Body for use with Jeep 4.0l IAC Valve
Custom Idle Air Control Body for use with Jeep 4.0l IAC Valve
Custom Idle Air Control Body for use with Jeep 4.0l IAC Valve
Custom Idle Air Control Body for use with Jeep 4.0l IAC Valve
Custom Idle Air Control Body for use with Jeep 4.0l IAC Valve

Custom Idle Air Control Body for use with Jeep 4.0l IAC Valve

5.00 out of 5 based on 1 customer rating
(1 customer review )

$75.00

In stock

SKU: ds-iacbody Category: Brand:

Description

‘DarkStar’ Custom IAC Body for Jeep Stepper Motor Idle Air Controllers

Custom machined IAC body for installing a IAC valve from a Jeep 4.0l motor, perfect for idle control with the MegaSquirt-II or later! Everything in the pictures is included, just add the IAC valve with o-ring and wire it up! 4 Mounting holes on the bottom/side depending on how you mount it with screws included. You should be able to find an existing bracket or spot on the firewall to bolt it to.

This valve body flows best if you plumb it so that pre-throttle air enters below the valve and exits above the valve to the manifold. This will give you a wider range of idle speed adjustment.

More Information:

  • Dimensions are: 2.25″x 2.25″ x 1.75″ OR 57mm x 57mm x 44mm
  • Valve bolt pattern is 1.8″ hole to hole with a 0.76″ ID hole
  • Part Numbers for Compatible Valves (provided by DarkStar):
    • Niehoff Part# 21774 (this is what was used in all testing)
    • Wells AC320

The Standard AC151 and Borg Warner 21774 have the smaller pintle and may work on larger engines but are not guaranteed. This IAC body was designed to work with the “large pintle” version, where the pintle measures 0.490″ to 0.550″ at the largest point.

OEM Application of this valve: 1991-1997 Jeep Cherokee, Grand Cherokee, Wrangler and Comanche (including submodels) w/ 4.0L Inline 6 VIN S

Hose barbs are for 7/16″ (about 9.5mm) ID hose.

Customers' review

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1 review for Custom Idle Air Control Body for use with Jeep 4.0l IAC Valve

  1. 5 out of 5

    Custom IAC bodyI always love DIY Autotune products. They fit well, install easily and are complete down to the smallest screw making my job so much easier

    Was this review helpful to you? 0 of 0 people found this review helpful

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What is in the box?

  • (1) Custom machined valve body, (2) NPT to hose barb adapters, and (6) mounting screws.  Note that the stepper valve itself is not included.  This is a mounting kit only.

What valves are compatible?

  • OEM Application of this valve: 1991-1997 Jeep Cherokee, Grand Cherokee, Wrangler and Comanche (including submodels) w/ 4.0L Inline 6 VIN S.  Part Numbers for Compatible Valves (provided by DarkStar):
    • Niehoff Part# 21774 (this is what was used in all testing)
    • Wells AC320

What MegaSquirt ECUs can control one of these valves?

  • Any MegaSquirt-2, MegaSquirt-3, or MS3-Pro ECU can control a stepper idle valve.  MS1 can not control a stepper.  A Microsquirt can not control a stepper on its own, but can drive a stepper with external hardware.  If you have an ECU that is not a MegaSquirt, please consult your ECU's manufacturer.

Where is the valve body manufactured?

  • The block is machined by DarkStar in the USA.

Does the valve work for forced induction applications?

  • Yes. If your throttle body is downstream of the turbo or supercharger, you will want to plumb the upstream port on this block to a spot in between the throttle body and the turbo or supercharger to prevent boost leaks. The valve itself is not going to move under boost - the screw mechanism is not easily pushed back - but depending on the settings, the valve may not close fully under boost so as to return to a suitable idle faster.

What size thread is on the hose barb holes?

  • They are 3/8" NPT pipe thread.

Questions & Answers

  1. 0 votes
    A

    There isn't one set of settings for using this on all engines - here is the manufacturer's advice for this block.

    First, you generally want to have no other air leaks into the engine, other than the IAC valve. This means setting your throttle plates to close fully and backing any idle screws off. I mention this because this is a common mistake that many make. On larger engines it is sometimes necessary to crack the plates just a bit to get good idle control, but it is best to start with the plates closed.

    That being said, wiring on the chrysler style IAC's can vary depending on which one you get. The best advice I can give you is to start by using a multimeter. Measure the resistances between each pin to locate the coils. in most of the Chrysler style IAC Valves the coils are on the two center pins, and on the two outer pins. So measuring across pins 2-3 (sometimes called b-c) you should get about 50 ohms,and between 1-4 (sometimes A-D) you should have about 50 ohms.

    Now that you have located the coils, you need to identify the wiring coming out of your MS. In general there are 2 colors of wire that make up the IAC system (not sure about your numbering). I have about 4 valves on my work bench and they were all a bit different. But, in general, wires of the same color go on one of the coils. The Mega manual really has the best explanation on this (http://www.megamanual.com/ms2/IAC.htm ), I know people always hate to be pointed there but it really does illustrate the figuring out of the wiring well. the info is about 2/3 the way down the page.

    As far as the steps go, this will depend on the valve you have. If it is a Chrysler variant, they tend to have more steps than the GM ones do. So the value for initial retraction is usually around 250-290 steps.

    Some other things I have noted are that the number of steps when the valve is in the housing can vary from part to part, even from the same manufacture. the step size also varies. Your biggest help will be the stim in this case. When I look to set up a valve I have a MSII V2.2 that I use that has wires soldered on the back (the DB37) that go to spade connectors. To match that I put spade connectors on a connector. This is usually fine for testing on a bench, but the JimStim actually has break out terminals for this sort of thing that might be a bit neater. The Stimv2.2 also has little jumper pads that you can use for this as well.

    I know you were hoping for an easy answer but I have unfortunately found little consistency in these valves. The OEM computers do have adaptive idle control that takes care of most of these variables and can compensate rapidly. (DIYAutoTune note - the current MS2/Extra and MS3 firmware does, too.)

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