Topic: stumbles and misses when under 180 degrees? cant figure this out

[84_yota_4wd]

hey guys i put a used engine in my pickup, its 22r-e it was out of an 86 so the head was double drilled for efi and a carb setup. i ended up rebuilding the carb off my old engine and using the old setup for the time being.

I have upgraded and replaced several things during the build. I went to ngk platinum plugs and ngk high pro wires, replaced the fuel pump and filter, flomaster, k&n air filter, along with flushing the engine with napa engine flush and changing the oil every 1000 miles to clean all the gunk out. i also run lucas oil stabilizer. i have done evrything i can think of to make this engine like new or better.

I have have problem with the truck sputtering and missing when it is cold under 180 degrees but as soon as it hits 180 it runs great no misses no sputter and even has a good deal of power for a 22r.

i have ruled out the timing, as its at a factory setting of 8 degrees, and i know its getting plenty of fuel. intake valves are set at .008 and exhaust valves arer set at .012 as well.

i just cant figure this one out anyone have a clue
 

Thanks mitchell

[TooRisky]

Sounds like a water temp senser...This senser tells the engine how to run when cold and hot...If it is bad one of 2 things will happen, it reads the engine is operating in cold winter enviroment, or its hot and operating in a hot enviroment. When the senser dies it will die in one of these positions, yours has died in the hot position, and starves the engine of fuel and possibly advances the timeng and runs bad till it is warmed up which is the better of the 2 ways it could go...

The senser is under $20.00 and is right in the front of the engine, very easy fix

[84_yota_4wd [OP]]

thanks for the input. unfortunetly mine are bypassed i know of 3 water temp sensors. 1. one the flange of the intake going into the head.2 and 3 are right by the thermostat and bvsv valve. i have not heard of these trucks sensors doing anything along these lines. 

But i am not all knowing by any stretch of thy imagination. witch sensor of the three runs this feature. and how would it be fixed. thank you.

[Plekto]

If it's a carb, and it has an electrical choke on it, my guess would be that it's not working right.

[84_yota_4wd [OP]]

good guess it was one of my first guesses as well.

but i rebuild the carb myself and took the aircleaner off when its running cold and its working just fine.

i have determined that its a head gasket that i damaged when i first had the new engine in. 
i had a fan clutch go out and it got up to 250. it seemed fine but then this started about 2 weeks later.

because this action was delayed i never put two and two together,

but it makes sense that i damaged it minorly and when the engine is cold there is a small leak and when it warms up the metal expands and seals the chamber.