stillrunnin

I have a 1993 Dodge Ram with a 5.2 liter engine. It runs good however when I let off the accelerator all the way the motor dies. It doesn't seem to be as bad in cold weather but in warm weather it will die every time if I don't manually keep the idle speed up a little with the accelerator. It was throwing an egr system failure code so I replaced the egr valve. That didn't seem to help. I have also put a new throttle positioning sensor on it. Does anyone out there have any suggestions? Thank you for any input.

Iowan

Im thinking idle air sensor and valve, I've had the valve start sticking closed , I tried cleaning it out but ended up replacing it.

stillrunnin

Can it be checked out some way or do you just replace it with a new one? Either way I will try it since I am stumped. Thank you for the reply.

RacerHog

Well... Im a little late to the party....
I would say pull the hose on the EGR and see if that fixed the issue, even after replacing.
However, Now your going to have to reset the TPS (Throttle Positioning Sensor) With a Scam Tool, like a DBR Scanner.
I also agree with checking the (Idle Speed Motor or IAC Idle Air Control) what ever it has on the truck.
Also, Check for vacuum leaks.... Some of those will blow out the throttle body base plate gasket.. Not to expensive or hard to replace if needed..

stillrunnin

I will pull the hose on the EGR and see what that does. I put a new IAC on about a year ago but I will check that out also. Thank you much for the suggestions. I will get back when I find the results.

Iowan

We appreciate you getting back with the solution to your problem, help’s the next guy.

stillrunnin

Hello and thank you for the input. I got back on the idle issue with my 5.2L. I pulled the EGR hose then drove it a couple miles through some stop signs and it idled down and stayed running although it stumbled a little before catching itself and idling smoothly on the last couple. Then it started dying again when I let off the gas. I still have a suspicion it is related to the operating temperature of the motor. As the motor gets warmer the idle seems to fall off. When I turn it back on after dying it idles perfectly so I'm still hunting for the problem. Any more ideas would be greatly appreciated. Thank you much. Stillrunnin

Iowan

Try removing the air hose in front of the throttle body and spray it down with carb cleaner while moving the throttle open and closed. I had a 95 that required this every once in a while.

RacerHog

Also Check for a faulty Coolant Temp Sensor..

stillrunnin

I will do that first thing. Thanks much.

stillrunnin

Interesting you mention the coolant temp sensor. The temp gauge never reaches operating temperature. Always runs cool even on hot days although on hot days it gets closer to operating temperature. I have wondered if the previous owner removed the thermostat. Is the operating temperature tied into the idle somehow? This is probably a stupid question but is the temp sensor the same as the sending unit?

RacerHog

You are correct in your assumption.
Yes it needs the correct thermostat or it will not go into closed loop.
The coolant Sensor controls the PCM on the circuit for drivability...
I think on those truck the temp sender is seperate that the Coolant Temp Sensor....

>>>> So you might find that putting in the correct thermostat will fix the problem??????

stillrunnin

Terrific! I will take off the thermostat housing and check out the stat. I was really at a loss where to look next. I will get back on here after checking the stat and let you know how it went. Thank you so much.

stillrunnin

This is an update. I got called out for work and haven't had a chance to check out the stat on my truck however that is first on the agenda when I get back home. I will then post what the results were. I wanted to let you all know I didn't find the problem after your help and skipped out without informing what I found out. Thanks again.

stillrunnin

Okay I returned from the job site this week and got back on my truck. A previous owner has removed the thermostat for some reason so this kept the motor from reaching operating temperature. I installed a new stat and my idle issue has apparently went away. Thank you people for the input that led me to the problem. This forum is the greatest.

RacerHog

Good To hear.... Hope you get it running so you can trust driving it all day again.... Cheers