I have a 97' Ram 5.9 with about 150,000 and intermittently it will not idle on it's own when started. Just dies like the key was turned off. It will idle if I keep the throttle pushed down a little and otherwise runs great above idle The only way to get it to idle again on it's own is by disconnecting the battery and waiting 5 or 10 minutes and reconnecting it. Then it runs just fine. This has been going on for a couple of years. But it may go 6 months or more running fine and then one day out of the blue, it won't idle. Never did anything to try to correct it until this weekend when I removed the IAC and cleaned it. I thought about replacing the it cause it's cheap, but just wound up cleaning it. Also replaced the battery with a new one after reading that might cause the problem. I haven't replace the TPS yet and I hate throwing parts at it. I just wonder why disconnecting the battery will fix it for a while if a part is really bad. It's starting to get worse and more frequent where it won't idle, so I was hoping you guys might have some ideas on where to go from here. Any tests that I can do to rule out any parts?

 

Disconnecting the battery and draining all the juice from the computer resets all the sensors and readings.

If a sensor just went out of whack and can't fix itself a reset might fix it.

It won't actually "fix" a broken part but it is free to do

 

When you cleaned the IAC, did you remove the throttle body and clean the IAC port out?

 

Wasn't so bad resetting it every six months or so. Now it's getting to where I have to do it every few days..

 

Yes. And the pocket it sits in was nasty. Sprayed the heck out of it with throttle body cleaner and wiped it out.

 

Is there any way to test the IAC or the TPS?

 

IAC can be tested with a scanner such as Snap On MT 2500. It is a stepping motor, so no other way to test other than for something to send it pulses and count the steps.

IAC can be tested. It is a potentiometer and can be tested with an ohmmeter. Make sure the resistance changes smoothly while rotating it. (with it removed and no power on it).

 

I don't have a scanner for the IAC, but I can test the TPS. I'll give that a try tomorrow. Thanks..

 

Have you downloaded the service manual from the FAQ/DIY section here?

 

I'll have to look and see if I have it. If not, I'll download it for sure. Dog gone truck usually runs so good, I rarely need it.