Well i have a great truck ( 1986 Toyota Pickup 22r 4spd) But... i have been having trouble with it cutting out... ok i run all the way to 6 grand... (shall we say) in first then shift to second and it falls on its face... why shifting matters i don't know but i can reduce throttle and it quits... i replaced the factory coil with a accel.. but i have not replaced the igniter... hot or cold it does it.... weirdest thing is that it did not start till i got my exhaust welded up.... not that i wanna drive like an idiot but i would at least like it to run right!??! any speculations???

 

I don't know much about carbs, but, to me, it sounds like maybe the choke or throttle plate is closing all the way and cutting it off when you shift. Like on efi with a manual, there is a "dashpot" that prevents the throttle plate from closing fast due to sudden decrease in speed.
Is there a dashpot or similar on carbs?

 

The butterfly in the bottom of tha Carb is moving freely.... but why would it act like it is losing a lot of gas or spark is cutting out???!!! who knows I have asked a few " MASTER MECHANICS" and all i get is the run around ... I mean I am very Mechanically inclined but this has rally got me baffled.

 

my 83 was kinda acting that way, it'd run fine down low but I'd get to a certain rpm and it'd just lose all power and start back firing through the carb. I've got scorch marks on my hood to prove it. Turned out to be my cam worn OUT! Lost most of all the lobes so I'd say check there, don't know if it'd be affected by the exhaust or not, just my two cents

 

Where's the Fab?

 

My 83 is doing the same exact thing, I bought a carb rebuild kit gonna take it off and get it rebuilt to see if it stops

 

check compression! i had this happen to mine, turned out i had a bent valve. machined the head, threw a new carb on it and i was back to normal. exchanged my carb for a rebuilt for less than 200$. check compression, pref a leakdown test as well. you can rule out any type of head problem that way.