Hi all..
I have a 1988 Toyota pickup, 140,000 miles, 22R engine. It is carbureted and well maintained...
However here is the problem. Whenever it is cold or cool out, the engine hesitates or stutters a bit until it warms up. During the summer or when its warm, the problem is diminished significantly to the point where only I can tell there is a problem. If its really hot out there is virtually no problem at all...
I have checked nearly every carb / vacuum related valve, the AAP valve, the choke, most vacuum switches, you name it. I recently tuned the engine up, checked the timing, new fuel pump, new fuel filter, new air filter and so on with no real improvement. The compression is right on the money and so is the engine vacuum. The engine power is also rock solid.
I am at a total loss. Although this problem is minor, I would really like to solve this situation. Could it be the mixture?
The problem is obviously related to the temperature. Are there any switches, sensors or devices that rely on temperature to operate? I am debating a carburetor rebuild but figure I should ask about my options first.
Cheers and TIA
Tom