chevy 250 with poor cold performance
 

hey guys ill be putting tags on my 79 this week and it still dosent run perfect. the truck has a 250 with pair smog injection, 3 on the tree, and 3.08's. the truck cranks up perfect every time but if it has been ideling for 3-5 mins the truck will not take off to save your life it will just choke off, but when it has been running for 15-20 mins it will take off reasonably good. ive tryed a bunch of stuff to get it fixed, ive replaced the weights and springs in the distributor, new cap and rotor, rebuilt the carb(rochchester verijet), installed a new heat riser, set the timming, bypassed all vaccume controled emissions devices, and attempted to adjust the carb. have eny of yall had this same problem?

Re: chevy 250 with poor cold performance
 

sounds like the electric choke may be bad or need adjustment

Re: chevy 250 with poor cold performance
 

Try adjusting the choke pull off linkage, to make it pull off less. If it's like mine it runs very lean. My next step is to drill out ever so slightly the idle jet port, when I find another unmolested carburator to experiment with. Plugging off the emissions equipment will only cause you more headaches. There is a vacuum hose leading from the carb the driver's side of the valve cover right above the exhaust that can get burnt through. Big lean spot potential.

Re: chevy 250 with poor cold performance
 

I may be wrong, but I think GM chose to run the choke off the oil pressure switch for that year. Something to think about.
My 76 with the non intergral head is a cold blooded beast and I can remember how my or my uncles 79's ran when cold.