I have an 89 w100 with the 5.2 in it. only in the fall and winter (i live in maryland so it gets pretty cold) my truck give me trouble with stalling a high idle and hesitation. the stalling comes when your driving it and you slow down to a stop, than it will stall. hesitation obviously when you accelorate.

when i am coming to a stop from any speed above 25mph the truck idles very high and doesnt want to downshift into first gear (its an automatic)until you are going under 5mph, and it idles high until you stop, than it will start to stall. BUT, it only does it when its cold outside. i have no problems in summer and spring.

whats the problem??? recently i have replaced the TPS sensor and tested the MAP sensor, new spark plugs and wires, oil change, new radiator, starter and air filter. perhaps the IAC valve? i plan on cleaning that today if i have time.

 

Have you checked for codes? Have you checked the timing?

You have an Idle Speed Control Motor not a valve like later vehicles so there is nothing really to clean. There is an adjustment procedure in the FSM.

 

Does it do this when it is cold outside and the engine itself is warm? Have you looked at the injector spray pattern inside the TBI?

 

codes 12 13 37 24 35 24 15 17 55, in that order came up. yes 24 came up twice. and it does it when it is cold outside even if the engine is warm. i havent checked timing or spray pattern. when you start the truck it idkes high and then slows down and runs smooth in park, and if you putr it in gear and sitr still it idles smooth. but when i start driving it starts acting up.

 

WOW! With that many codes I would clear the codes and drive it to see if they all come back. Some of them may be old codes. Codes 13, 17, 24 could be responsible. Here is a list of what the codes mean.

https://dodgeforum.com/forum/1st-gen...formation.html

I would still look at the spray patterns. Does the engine warm up to normal operating temperature? You can run electrical tests on the coolant sensor. Do you have a manual?

 

i have the list of codes, but no manual. today im gonna check the coolant temp sensor, i just put a new tps sensor on bc the old one was cracked, that made code 24 come up, any idea why? what is the eisiest way to test the temp sensor?

 

Any time you replace/work on things that can set codes you should reset the codes as that work can set codes.

Coolant temp sensor should read 17900 to 10800 ohms at 50 to 80 degrees F and 1170 to 820 ohms at 180 to 200 degrees F. Reference voltage at the connector should be 5 volts. Remember there are 2 H2O sensors. You want the one by the thermostat housing as the other one is for the dash gauge.

 

new temp sensor was only 9 bucks so i just got one and put it on, it helped smooth out the idle but its almost a little too low now when idleing it in gear. it is still slow to downshift when im slowing down and idles high sometimes when coming to a stop and than after i stop the idle gets real low. but its a warmer day today so it may go back to being screwed up when its colder. how do i reset codes?

 

Disconnect the battery for about a half hour and the computer automatically resets. I like to reset the computer any time electronics are worked on so the computer can relearn from its base setting.

 

okay ill give it a try and than test the codes again.