I have a 98 Dodge ram 1500 5.9L SLT and starts good every time. But when
it is cold out you have to let it warm up. if you don't then try dropping it into
drive or reverse and it stalls out in a couple of seconds unless you put it back
into park and rev the engine a tiny bit. Any suggestions? thanks

 

For future reference:
https://dodgeforum.com/forum/dodge-r...s-section.html

 

Clean the throttle body/IAC. DIY in FAQ section.

 

cold idle rpm should be about 1000. warm idle about 600.

if the cold idle RPM is too low, replace IAC and clean the well that it goes into including the little tiny hole in the bottom of it. don't forget the o-ring on the new IAC. sometimes its lose in the box and you don't notice it.

 

Thank you. i will try cleaning and changing that. but i also noticed that its
been 65 degrees out and the truck was already warmed up and i drove it for
about ten minutes and then another couple of miles to wally world. then i started it and it was kinda chugging like i was holding the gas peddle down
and it was really moving just idling and then i pulled into a parking spot and
it went to about 500 rpms and sounded like it was going to stall. i shut it off
and waited a minute. then turned it back on and it ran fine the whole way home and didnt chug and anything. any suggestions? maybe another sensor of
some sort? thanks

98 dodge ram 1500 slt laramie 5.9L

 

if the idle is surging up and down and up and down, between 500-1500-500-1500-500-1500,
replace throttle position sensor (TPS).

 

It doesn't surge between 500 and 1500. I noticed that when I start it the temp gauge is at 130 for cold like when you first start it and it will just start up good and idle at 750 which I notice is good. But then I will let it sit for a minute or two and it will drop to 500 Rpms and start to stall out. Then I shut it off and turn it back on and it runs at 750 and runs fine while driving. I bought a new map, throttle position, and idle air control valve to see if helps. Any suggestions about the problem above?

 

Same thing happened to me last year. I believe it was a mixture between IAC and a plugged transmission filter. I changed the IAC and tranny filter/fluid at the same time and it hasn't been a problem since.

 

Okay yeah i figured you were right about the iac. i just bought it and was
gonna change all the fluid so ill try changing the tranny fluid with it and see
what happens. Thanks for feedback i really appreciate it.

 

its probably not the MAP sensor. they almost never go bad.
on the other hand, the IAC and TPS seems to be fragile and prone to failure.

save the MAP for last. if one of the other's fixes it, maybe you can return it. they're expensive.