QuestionHi, my 16 year old son has a 1970 C-10 that is a nightmare to start on cold days. We have replaced the battery (which it tries to drain when starting). New fuel filter and air filter. Any suggestions would greatly be appreciated. Thank-you, anna
AnswerI'm really not signed on to handle truck questions, but since a C-10 is basically the same as far as engine starting as a passenger car, I'll see if I can help.
I'll need you to get me some more information, though:
We'll need to do some research to find out what is going on with it:
After a cold night, go out and remove the air cleaner from the top of the carburetor, then look at the top of the carburetor - there should be a metal flap that is closed, preventing air from entering the carburetor from the top. To learn what I'm talking about, look at it before it cools down to see what the carburetor top looks like before the flap closes, so you can see if it changes when it cools down overnight.
If the flap is not closing, your automatic choke is not working. It can either be stuck, or misadjusted, or broken.
Before I get into the details of how to correct those problems, tell me what you see in the morning. If the flap is closing, then the problem may be elsewhere, but I can sit here typing all night and still not help you if I don't know if the choke is working.
If the flap IS closing overnight, stick a finger down there and, with someone holding the gas pedal to the floor, push the flap back open while you feel for any restriction or hang-up in it's operation. If there is any such restriction or friction or reluctance to move, get some carburetor spray cleaner ("GUNK" is a good brand) from your local auto parts store and spray all the moving parts in the choke mechanism while you move everything that moves when you open and close the flap.
Back to the research. If the flap is closing OK, hold it open and take a flashlight and look down the maw of the carburetor while your helper releases the gas pedal and than mashes it to the floor again. You should see a healthy squirt of liquid fuel go from a nozzle or two down into the carburetors - this is the "accelerator pump" priming the engine. If this doesn't work, the engine will be very hard to start in cold weather, and the only cure is to have the carburetor repaired or replaced.
It is also possible that the gas is draining out of the carburetor overnight due to internal leakage or evaporation after the truck is parked, to investigate that, keep a small amount of gas in a container, and put about 2 ounces of liquid fuel into the top of the carburetor before you try to start it in the morning - if this cures the problem, you know you have a lack of fuel situation. Probably the easiest and most practical way to cure that is to buy and install an electric fuel pump, wired to the key so that as soon as the key is turned on, the gas will be pumped into the carburetor - then the engine will start immediately if everything else (especially the choke) is working right.
I've gone after this on the assumption that your problem is that the engine cranks OK, but simple won't fire. If that was a wrong assumption on my part, tell me and I'll start all over on it.
If you write back with more information, please tell me which engine the truck has, and what kind of carburetor (2 Bbl or 4bbl, and if it has been modified in any way, especially with regard to the ignition or fuel system.
Also tell me what you mean by "draining the battery".
Anytime a vehicle doesn't start within the first few seconds of cranking, STOP CRANKING! You will only overheat the starter by cranking for more than about 15 seconds - this will quickly ruin the starter, and kill the battery too!
Dick
