cold natured truck problems

[Cornfield creations]

Yeup, it gets cold, and then the little annoying problems come out.

Well I have a 76 k-10 350 with a quadrajet. It has been rebuilt and runs great when warm outside, but when it gets cold outside it runs crappy. Driving it at first it drives great, but when it get inbetween warm and hot it wants to die. Pretty much before the thermostat opens. Pull up to a stop sign wants to die, push on the gas too hard wants to cough and sputter and through the carb, but the weird thing is when its good and warm it runs fine. Kinda weird

I thought maybe the choke wasn't opening up (electric), but i checked and it looks to be opening, but maybe not all the way. Seems it kinda stays half open, not quite sure if thats how it always is or not.

Anyone else run into this problem?
Thanks in advance!

Matt

 

[dyeager535]

Within 10 minutes of the engine starting, the choke should be fully open.

GM electric choke coils vary in how fast they are calibrated to open, but 10 minutes is the highest I've seen.

If the choke blade isn't fully open, either the coil or the rod that connects the coil to the choke blade isn't adjusted right.

 

[diesel4me]

sounds familiar...

I had a 69 GTO with a 400,that had a Q-Jet with the exact same symptoms..ran good stone cold,or fully warm..but in between,when it was "lukewarm" as you said,at the point where the choke was fully open,but the motor was not yet at 195 degrees,it would stall at idle sometimes,run rich as hell,and idle poorly,you'd have to hold it at fast idle to keep it running,etc...then after it hit 160 on the temp gauge,you could hear it smooth right out as if someone flipped a swtich!..

I "fixed" it by removing the thick "insulator" gasket under the carb (base gasket)--and replaced it with a thin "regular" gasket..and I replaced the missing aluminun foil hose from the air cleaner snorkel to the "heat stove" on the exhaust manifold..no more problem! I found out it was "carb icing" causing my problem--happens a lot here in my area,where its cool and foggy a lot--adding "dry gas" helps too,but wont cure it by itself...

A lot of small planes crash because of carb icing.. --makes driving a car with it challenging too,in busy traffic conditions..

... but during the summer I had to put the thick gasket back on,and remove the "hot air" tube..or it would vapor lock once in a while on 90+ degree days..

I have to do this to my C10 too,its getting colder now,and it ices up pretty badly,thanks to an aluminum adapter under the Edelbrock carb..gets crappy gas mileage when the carb runs too cold,as well as running poorly until it warms up..