salad

That's what I was afraid of.

I dunno what's so hard about a DPST.

thatXJguy

I think it would still work with some wiring knowledge, then again I'm no electrician.

I've seen people wire up completely simple aftermarket switches that have worked, and this is just an OEM-style alternative. The hardest part about this whole thing is finding an EXT idle switch since they're so elusive.

mannydantyla

sorry, there's a lot of confusion in this thread

so, just to be clear:

All that is needed to set the idle speed to 1,000 RPMs is to connect the A12 pin of the ECU to ground. This is accomplished with any ordinary 2 prong (SPST) switch by connecting one prong to the A12 pin and the other prong to ground. When the circuit is complete, idle speed will be pumped up. When it's open, idle speed will be normal.

Correct??

Bugout4x4

I have been curious about this option for quite awhile now. Thank you for bumping it and I would like to know more too!

mannydantyla

I suppose it would be pretty easy to find out.

Take a wire and jam it into the A12 pin of the ECU. Start the engine. Touch the other end of the wire to bare metal (ground). Observe the change in RPMs.

Bugout4x4

Oh man... The chances of needing to go get another ECU would prevent me from doing this without some very good homework and trusted knowledgeable expert advice first!

wizardpc

Correct. Simply ground A12. That's it.

The fancy stuff is all about using the rare and expensive factory switch, or using a lighted switch with a relay.

But basically, just ground A12.

Bugout4x4

Fantastic! Is this on any ECU of these years even without needing a specially programmed ECU?

wizardpc

Automatics only, reading back a little on the thread. And A12 is for obd2 xjs. Earlier ones are different

Basslicks

FIFY

wizardpc

Lol. I actually had a 93 police package with extended idle from the factory, so i wouldn't know

God I miss that Jeep. The only vehicle I regret selling.

Bugout4x4

Thank you! I'm going to try it unless someone says "Don't... it will fry it!" lol

I'm going to guess that it will probably only apply in park or neutral though?

Basslicks

Haha... yeah from what I've been reading, there's hope for those with the 93+ OBD1's. I've tried and tried and tried to find something for my '92 with no luck. Just a bunch of suggestions with dead end results.... and I really don't wanna fry my PCM trying things suggested without ACTUAL evidence of it working. If I had a spare PCM, it'd be a different story.

wizardpc

Correct, only park and neutral.

Bugout4x4

Now I will work on overriding that somehow. lol

Couple years ago there was a lengthy discussion about this here and what is being shared now about A12 never came up at all, so it's a revelation for me to hear this. For us out here in the middle of the summer it would be nice to be able to idle it up and cool it down during the cool down "rest periods" that plague all makes and models when out crawling in first low range because it is just so hot even with your cooling system in tip top shape.

But we go back into some pretty secluded wild country and most times it will be just a jeep trail for miles and miles in first low. Ever ease along in first low for ten miles at a time? To be able and kick the throttle up a bit while easing along instead of having the terrain jerk your foot on and off the throttle for ten miles in first low would be a great relief and actually easier on the drive train. I was working on fabbing up a bracket to mount one of the old style adjustable "dashpot" solenoids to interact with the throttle linkage, but if I could do this electronically rather than mechanically it would be much better.

To somehow override the cruise control minimum speed activation setting would be the best ticket. But this might be impossible?