Hi I have a 1997 Dodge ram 1500 with the 5.9 and i have a BIG problem iv spent days and tons of money on. When ever i start my truck it runs fine tell i get to a stop light, when im stoped the idle goes way down so the truck is shaking and wants to die (sometimes it does) and it does it almost ever time after i start to drive it. It will do it if it is warming up for a few minutes to. but if i spray Carb & Choke Cleaner into the air intake it kicks back up to narmal idle. So far i have put a new temp sensor, IAC motor and the fuel pump and pressure tested good. has any one had this problem or might know what it could be?

Thanks Dan

 

I would try an intake and fuel injector cleaning. At the same time check and make sure there is no leaks (manifold, vacume hoses ect)

 

have you checked for any codes stored? how old is the o2 sensor(s)? sounds like it's getting flooded. when you changed the IAC valve did yo clean the throttle body? there is a small air passage down there with the IAC that could be plugged. usually when a magnum motor dies at stop lights/signs the 1st thing to check is the TB and make sure it's good and clean. also, what about the base gasket under the TB...

 

Iv ran fuel injector cleaning and all the different octan gas throw it, nothing worked. it will never give a engine light. iv hooked it up to the computer and not 1 code. the IAC is running fine. the TB is clean everything is clean. The O2 sensor could be bad never replaced it but im not so sure if that could do it becuase it only starts to die on cold starts tell it is warmed up (being on the road for 10 mins or so) anymore ideas?

Thanks Dan

 

ok, i still say check your o2 sensors... my truck had a similar problem and the heater wire for the o2 was grounded which blew the heater fuse and it acted very similar to what you describe. you might also want to check the heater relay for the o2's should be in the fuse box. you should be able to swap it with another relay and see if the problem comes back.

oh wait after re-reading your last post, I see it is a problem when cold... it is in open loop mode... what about the map sensor? have you checked that? the map sensor is always monitored, open or closed loop mode.

 

Well i mean a cold start as a fresh start not like cold out side it does it in winter and summer just for the first 5 to 10 mins then it wont start to die after that but yea ill look to see if i can find a new O2 sensor and see what happens

 

How miny miles do you have on the truck and have you checked the air filter.

 

the motor will run in open loop mode until it's at operating temp, above 170~175 deg. that's what I mean by cold start.

 

119,000 miles new K and N air filter but yea steve00ram360 cold starts) what do u think my best bet would be with having not to try 100 parts that i cant return (lol) iv spent about 200 bucks as it is trying to find it

 

well, here's what I'd do... go get a bottle of canned air (turned up side down so the cooling agent is released) or some freeze spray and when them motor is warm and running, hit all the sensors so the chill down real quick. if the truck dies on any perticular sensor then you've found your problem.

you can also do this to the relays but I doubt that is your problem at this point. since your truck is dying, start with the crank sensor, then the map sensor.

oh and btw, did I mention to pull off the TB again and make sure it's cleaned real good? make sure the small air passages are not plugged.

bottom line... I think one of your sensors is dying when cold (opening up) and when hot, contacts expand enough to make contact. seen this many times in the electronics industry