Stalling Help!!

[motofool23]

hey i have a 91 4x4 and it has been acting funny lately. it seems when i come to a stop and then try to go again it will kinda hesitate go and then stall. there is no CEL and i notice that when i stop and before it stalls the rpms go up. i also noticed black smoke coming out of the exhaust. i have cleaned the IAC and put a new fuel filter on. i dont know what to do it stalls almost at every stop any suggestions would be appreciated.

 

[MrShorty]

When the engine stalls like that, the computer doesn't necessarily get a chance to illuminate the CEL. I would still pull codes in case the computer is aware of what happens that makes it stall (in particular looking for continuous memory (CM) ignition codes). See tests at www.dalidesign.com/hbook/eectest.html for how to witghlittle more than a paper clip.

One non-eec item that comes to mind based on the black smoke. The diaphragm in the fuel pressure regulator (FPR) frequently ruptures, which can dump a lot of excesss fuel into the intake. Run the engine, then check the vacuum line to the FPR for gasoline.

 

[motofool23]

I havent had time to pull the codes but i went to look at the vacuum line on the FPR like you sad and i found that the vacuum line was disconnected. i reconected it and went for a little drive and it only stalled once rather than many times. so i think im gunna drive it for a day or two and see whats up what do you think??

 

[MrShorty]

With that vacuum line disconnected like that, it would have introduced a significant vacuum leak, which can cause all kinds of problems.

 

[motofool23]

i have been driving it around and it still stalls so im going to check if there is fuel in the vacuum line tomorrow, but could that line being disconnected have created other problems?