'88 B2200 continues " Loping?" after ignition shutoff

Well I finally got my truck home last night, ( in previous thread ) been looking for a seat bolt, found one and put it in before even took off to the house. Now after having stopped at a local grocery store and switched off the ignition the motor still turned over a couple times sputtering or chugging out. noting horrific sounding or anything but like it tried continuously tried running after loosing spark. Now i'm thinking that i may have a vacuum line that's not sealed correctly on the carb, or it's just sucking a lot of extra air in through the carb,( tuned wrong?) and built up deposits inside the motor are causing small sparks causing it to try and turn over. Or it's just leaking air through a bad seal on the intake, carb adapter plate or something? not to sure myself but those are the best educated guess's i have. I've let it run and ran it a lil hard up an down the road, just see if it had been where the truck set for several months and maybe just needed be ran for a little while. But it still did it even after having rode around several hours. I've tried loading the engine, before i shut it down slightly ease up on the clutch putting pressure on the motor and shutting it down, it didn't do it after cutting off this way.
Was wondering if anyone had ever encountered a problem like this or if it's a whole bunch nothin i'm worried about lol.

Sounds to me like your motor is dieseling. It could be caused by too rich of air fuel ratio (compression igniting the unburned fuel) or it could be from valve train issues but if the truck is running okay I'd rule out any valve train problems. I wouldn't think that excess vacuum would cause this to happen but Idk I'm not all knowing on these things. I will say I had this problem with my truck before I installed a weber. (the stock carbs are crap) and even after the weber until I adjusted the mixture screws.


Hope this helps some...



Fred

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Appreciated, and no it has no issues running, no loss of power, no bogging or chatter, clicks,ticks hiccups, anything, but thank you, i'll try adjusting the air./fuel ratio mixture screws and let ya know how that turns out. this was one i was leaning towards more than anything but was curious as to what anyone else had to say. May even go as far as to run a full tank of some high test through with a fuel cleaner in the gas system. but thanks for the input.