My son travelled from Jacksonville, FL to Trenton, GA over the holiday weekend and was anticipating getting some work done on his truck while there with some friends who are more knowledgeable about mechanics than he. He had a loping problem on startup and hesitation upon acceleration so they decided to clean the IAC. Put it back in and now have worse problem of stuck at high idle (about 2000rpm), so they put new one in and still stuck at high idle.

They had planned to put in new motor mounts so they went ahead with that and figured then they would go back to high idle issue. Mounts done and, of course, still stuck at high idle. Meantime it is now Sunday, he has no internet access where he is, and he needs to get back to Florida for work.

Getting codes 12, 25 and 45. Have tried to reset computer 3 times but as soon as battery is reconnected the codes are still there without starting, so doesn't appear to beresetting. They don't know what to do and son doesn't have the money to just replace parts until he gets to the right one. The truck gets very hot when running and we're afraid of damaging the engine. Any ideas or help would be MOST appreciated!!

 

Well, they just bought a new IAC. The cleaned one didn't work when they put it back in, but maybe the damaged the pintle cleaning it. The new one they put on yesterday, didn't fix the problem either, so they returned it. They're thinking maybe the new one was defective, so they got another new one. We're just thinking it MUST be that, because the high idle problem started when they first took out the IAC to clean it. God, I hope this fixes it. Don't know what to do if it doesn't!!

Why in the world won't the computer reset? Disconnected negative terminal and held ignition key in start position for 30 seconds, then waited 10 minutes to reconnect terminal. Did that twice. Third time disconnected negative and positive terminals and waited 45 minutes, holding key in start position for 30 seconds two times during 45 minute period, and still no reset. It could very well be that all it needs is a reset, but we can't get it to do it.

 

You will get a better responds if this was posted in the Gen1 section. Not sure how to fix, someone will chime in soon Im sure.

As for the codes, the computer may be still finding the problem which is why its "seems" to not reset.

Also have you downloaded the factory manual for reference (in the FAQ)?

 

Found some info, try testing the IAC

Quote from crazy
Take the IAC off. Push the tip as far in or out as it can go reinstall. Start engine. If your engine dies or idles high and stays, then it is bad. If your engine goes to a normal idle then it is okay.

Also check your vacuum lines, brake booster line and PCV vacuum for leaks.
A leak can allow loss of vacuum raising a engine's rpms

What engine is in the truck?

 

v6 3.9Liter

 

I'm trying to help my son LD because he has no internet access where he is, but I don't really know what I'm doing. He's a web developer and very familiar with forum usage but I'm not very much so. I don't know how to get the factory manual from FAQ. Could you explain?

 

Should have added it is a standard transmission in case that makes a difference.

 

Thats okay we can help you. The forum administrator can move your thread. You will get more results under "1st Gen Dakota" at the top of the page.

Here is a direct link the the factory Manual (its for the 2005 but is similar to your 1993)
Factory Manual Here

Here is a direct link to the FAQ
FAQ HERE

Also try doing a "Advanced Search" on the search toolbar found above. There is other people with common problems.

Maybe someone else can help you more as you need help asap. Also try what I have suggested.

 

One last thing, apparently a EGR valve can cause these symptoms... read through this thread while your waiting for more advice. 93 dak High Idle

 

a code 25 is a wiring problem in the IAC circuit. Check the wires and make sure they aren't cracked/ corroded or an exposed wires showing. That will cause problems all day every day.