Stalling when stopping


#1

Have 86 Chevy K10 pickup with an auto- matic transmission that stalls when stopping. It then is slow to start unless the throttle is pumped several times. Have replaced the fuel filter and pump to no avail.


#2

More than one fuel filter?


#3

Does the engine idle normally? If it does, the problem may be caused by the torque converter lock up staying engaged. The torque converter lock up should release when the vehicle speed drops below 30 mph.
Change the automatic transmission fluid and filter, and see if it improves. If it doesn’t you need to look into the A/T lock up more closely.


#4

My guesses would be either a weak spark or a malfunctioning float bowl. Or a bad idle stop solenoid.

Prop the choke open, look down the throat of the carburator with a flashlight, and manually activate the throttle linkage.

If you’re getting a spray of gas, the float bowl is full and the accelerator pump working. Proceed to begin looking at the ignition system.

If you are not getting a spray of gas, check the line pressure to be sure that’s to spec. If it is, then you have carb problems. Could be the float bowl or the idle circuit. Perhaps even the idle setting.

One added thought: this carb may have an “idle stop solenoid”. This would be a device that when energized holds the throttle to idle position. When deenergized it allows the throttle to close completely and choke the engine to prevent dieseling. If you have on and it isn’t functioning it’ll give you your symptoms.