Hello all,
I am new here. I am at my wits end. My boyfriend and I have a 1977 Ford F-250, it has a 400 engine, 2 wheel drive, 4 spd transmission with granny low gear, and long wheel base. We love this old truck but it has really started causing chaos around our house here lately.
I am looking for suggestions to try. My 27 year old son is another old Ford Enthusiast, who is also a "shade tree" mechanic, so whatever suggestions I can get, he will apply..
Ok, the problem is, when the truck first starts up from dead cold, it will take about 5 minutes to start its spittin and sputterin. Then it does it the whole rest of the time that you are drivin it. It does what we call "biting". Kinda like it is cutting out and picking back up. Similar to the way that a vehicle does when it is running out of gas. But we keep plenty of gas in it and have even switched brands in case of bad gas.
We have replaced all of the following...plugs, plug wires, inline fuel filter, strained and cleaned the gas tank, fuel pump, distributer-cap-etc, rebuilt the carberator with another 2 barrel like it had before, alternator and belt, plus numerous other things not pertaining such as clutch, brakes, etc....
We are open to all suggestions short of a new motor. We can't afford to go that far just yet. Any help anyone can offer us is deeply appreciated.
Thank you,
Rhonda

 

OK how about the choke is not opening all the way...thus causing a too rich/lack of air condition after the engine warms up.
Do you notice any black smoke out the exhaust when it starts acting up ??
Try checking too see if the choke is open the next time it starts the problem.
Another thought is a bad coil, sometimes they act up when they get warm...but usually it causes a stop and refusal to start condition...but you never know.
Also the ignition module may be faulty, it can act the same way.

 

Hi Sparky,
Thanks for replying so quickly! No, there is no black smoke when it acts up. I will definitely have them check the choke tomorrow too just in case. Our next step was gonna be the coil but we really didn't think that would be it, cause like you said, it usually causes a stop- then not start up problem. As for the ignition module, thats a totally new thought to us, heven't even thought of that one...Thanks!! We'll check that out also.
I think this truck also has some timing issues too. It is slightly hesitant when first starting up. Not bad but slight. Was gonna have somebody try to set the timing tomorrow. Think that could be part of the problem also??
Thanks again for answering so quick!!
Rhonda

 

You can take the ignition module to a parts store for free testing. A broken wire in the distributor pickup module or a bad module can cause the same thing. If the timing chain is worn out and has slipped a tooth the same thing can happen. If the timing is off by 10+ degrees you may want to check out how much slack there is in the timing chain. There are checks for this in a good manual.