Off Road Engineering
Back to Tech Reports Main Page
Back to Features Page

ROCKCRAWLER installs Off Road Engineering's Electronic Idle Speed Controller in the Project TJ.

Hand Modeling by John Farrington, Jr.

Ever notice how rough a ride you can get on the trail when rockcrawling over obstacles? You know, everytime you hit a good-sized rock, your foot mashes the accelerator and then off and your 4x4 jerks and lurches all over the place, right?

What about when you're winching and you really want to keep a steady amount of throttle going to keep the winch going and your battery charged? You can also get that accelerator bounce.

One way you can solve these problems is by installing a hand throttle, like we did on our Project TJ. (see the article here) Though the hand throttle is a great fix, there are disadvantages to that setup. You can set your hand throttle however you like, but as your motor's computer constantly adjusts the idle speeds, the rpm's may climb or fall at will. Not good if you are keeping it cracked open to use an under-hood welder and you are out of your rig.

ThrottleSo what's another alternative? We got a hold of Off Road Engineering's new Electronic Idle Speed Controller. This nifty little black box intercepts the signal from your motor's computer by tapping into the wiring harness. It then returns the signal back to the idle speed motor. Basically, it just makes a loop.

The box has an on lamp and two switches. When you want to use the controller, you flip the left switch to turn it on. You can then raise or lower your rpm's with the right switch. Because the box intercepts the computer signal, your rpm level will not vary like the manual hand throttle. The switch can be "bumped" up or down in steps or held in to rapidly raise or lower it.

Off Road Engineering claims a top rpm level of 3,000 rpm, however, on our rig, we max out around 2100 rpm, which is fine by us. It's enough to use our Premier Power Welder and it's way more than we'd ever need on the rocks.

ThrottleThe box installs incredibly easily. We did ours in under an hour. It comes with everything you need, including wire-ties, a detailed instruction sheet, and 6 nifty 3M "T-Taps" to tap into the wiring harness.

The instructions were easy to follow. We're certainly not electrical geniuses around here and the crisp instructions made simple work out of the installation.

One thing to note: It is possible to decrease rpm's enough to stall the motor. If you do this, you will have trouble restarting your truck, because there is a piston which varies the airflow into the throttle body. That piston gets set by the unit and will be left in place if the motor is stalled out. If it happens (like it did on ours), you will have to give it a lot of gas to start it and keep it running. Once it idles again, it should be ok. This may also set a code in your computer and you may get a CHECK ENGINE light. It's ok. Don't panic! Simply unhook your battery for a few seconds and re-hook it and you should be fine.

What's it work on?
ALL Jeep, Chrysler and Dodge fuel-injected motors up through the 2003, most General Motors engines (including TBI, tune port and MPI), and Mopar, Holley and Howell fuel injection kits.

Contact Off Road Engineering at:
26741 Portola Pkwy.
Suite 1-E PMB 489
Foothill Ranch, CA 92610-1743
Phone: (949) 581-2991


WARNING: Do not under any circumstances use this device on the road or highways!

On to the install

©1997-2010 ROCKCRAWLER 4x4 and Off-Road Magazine. All Rights Reserved.