Hi, I recently bought a 1990 w150.
since i bought it, it has been stalling whenever i decelerate via breaks unless i give a little gas. we had a bandage fix via increasing the idle RPMs but when driving at night with radio and headlights on it began stalling out again. Alternator and Battery give good charge, I checked the stored codes and the only one of concern i saw was 37 for a Torque converter solenoid which after research, stalling while decelerating is a symptom of.

One of the past owners did put in a Autotronic Controls Corp. propane duel fuel system but it stalled with both fuels but i would like to take it out regardless.

any help with either issues would be appreciated, primarily the stalling issue.
Thanks

 

Most likely the idle motor.

 

Is there a recommended way i could check that? it seems to idle fine even before we tweaked the idle rpm. And the truck always starts right up after stalling

 

Does it have any issues with idle when you start it up/shut it off or is only when decelerating?

 

only while decelerating, and i cant hear much of a struggle from the engine just see my oil pressure drop until the engine stops. We checked for vacuum leaks but didnt find any, couldve missed one though.

 

went for a ride to try to recreate it. noticed that if my 4x4 is in neutral and my shifter is in drive it runs rough when i release the breaks. but it didnt stall, slammed the breaks, gentle on the breaks, lights on and off, went fine.

 

That's what i was going to ask next, Does it do it when you shift into neural. I think the converter is staying locked and when slowing to a stop it will stall the motor. Try clearing the code and see if it comes back. Need to determine if the pcm is keeping the trans in lockup or there is an issue with solenoid. What transmission do you have?

 

didnt seem to in neutral no, cant remember the transmission specifically but its a 3 speed automatic with overdrive

 

cleared the codes and took a ride. Came back with 33, 51, and 37. 33 id assume wont matter since i have no ac period, and i did notice what might be the engine running rough when coming to a stop? i thought it was just crappy shocks or something but it could be then engine sorta jumping

 

Long delay, had school and other issues pop up my goodness. Had a burst of inspiration one late night and finally got my transmission, its the 46RH.

We unplugged the overdrive and that definitely helped with speed especially on hills, but stalling still occasionally happens as well as a new weird issue of losing acceleration almost like im locked in top gear. Might have to give up on it, money and time are in short supply