sudden power loss for a 72 c-10

[dagwood]

hello, i have a 72 c-10 with the 250 c.i. engine and 4 speed manual transmission. at an idle, the truck seems okay, but when i try to accelerate, the engine starts popping, and acts like a cylinder stops working. the distriburator cap was just replaced last year, by the previous owner. the spark plugs are new. but the coil and plug wires are of unknown age. could either one cause the truck to act this way? or should i just save up to get the engine rebuilt? i am in need of your advice
thank you for your time

[TJSc20]

over time the insulation on your plug wires can crack and cause a short. i would replace them anyways and i would replace your fuel filter and see if you have any luck

[usmcchevy]

In person I could tell you in a second, but just your description tells me points and condenser or carb problems. If you still have points, they are probably over due to be replaced.

[cdowns]

lack of routine maintenance could b cause of poor performance

[ner0]

I have a 250 with a new carb and new fuel filter it is doing the same thing. When I shift into 3rd gear it falls on its face. I replaced my plugs, wires, rotor, cap and points. The fuel filter is still full after the engine dies on me. Today I am putting a new distributor on it.

[geezer#99]

Sounds like either your timing is retarded or you don't have any heat to your intake. If the 250 is all stock the deflector under the carb may be stuck open and you're not getting any heat to your intake. Fuel won't stay vaporized if it's too cold.
If you're putting in a new dizzy hopefully you're swapping to an HEI. Best thing I did to my motor.

[ner0]

In the best Gary Coleman voice i have "what you talkin 'bout Geezer?" I am going to google carb deflector but incase my search doesn't make me any smarter will you expound because what you are saying just sounds like it is going to work.

[geezer#99]

Expound I will. There's probably a technical term for it. Heat riser valve or something like that. Under your carb where the intake is bolted to the exhaust manifold there's a plate which closes off slightly and deflects hot exhaust gases to the underside of your carb. All you will see is a lever on the outside with a spring on it and a pin to attach the spring to. You should be able to move it by hand. People used to jam them wide open thinking it helped flow through the exhaust. Problem is you get no heat to the carb and it misses and bogs. I have headers on mine but no heat now on the stock intake. It misses and bogs even during outside temps of 35C. About 90F in the shade for you. I'm putting an Offy intake on soon with a heat plate plumbed to my cooling system. Provides enough heat. Cures the bogs. There that's what we're talkin' bout Willis!!! LOL!!!

[gonzo6869]

Check your fuel filter or filters. I had two on my truck and did not know about the second one till I did some searching. The second filter was pretty well plugged and I was having the same problems you are. You might want to try taking your carb apart and give it a good cleaning. I am almost positive that you have a fuel delivery problem.

[dagwood]

this o'chevy hardly seen any maintence over the last 10 years. Mostly just abuse, since i first seen it. Common since, would had told me to pass on this truck, but i just did not want to see it get scrapped.yes it still has the points and condensor on it. i tried replacing them but could not get a proper set of point from the local parts houses. When i got the truck, it did not have a fuel filter in the carburator. So i just replaced the in line filter the previous owner installed. i had not been able to find a proper replacement filter for the carburator. So today, i bought a new distriburtor cap, rotor and plugs and wires. Thinking i was playing close attention to the firing order. i ended up messing it up badly. So my question, Does the distriburator rotate clockwise?

[AirSpeed]

Originally Posted by dagwood

hello, i have a 72 c-10 with the 250 c.i. engine and 4 speed manual transmission. at an idle, the truck seems okay, but when i try to accelerate, the engine starts popping, and acts like a cylinder stops working. the distriburator cap was just replaced last year, by the previous owner. the spark plugs are new. but the coil and plug wires are of unknown age. could either one cause the truck to act this way? or should i just save up to get the engine rebuilt? i am in need of your advice
thank you for your time

Did this suddenly happen? Was it running fine before? Does it ever accelerate normally? I have had the same symptoms in a couple of my trucks, it turned out my nylon timing gears had fallen apart in one and the other the chain and gears had worn so badly that the chain slipped and changed the timing so bad that it would backfire every time I gave it gas and would not accelerate at all.
If its the case, it's a pretty easy fix, you will have to pull the water pump but that's not hard to do, when I did mine I replaced the water pump while I was at it.

[dagwood]

in a way, i guess you could say that it happened all at once. this started, if you could believe just by changing the engine oil. then the truck would not refire. in which i found out that the points was out of adjustment. to make a long story short, i believe i may had made progress today. i went ahead and replaced the distriburtor cap, rotor, spark plugs, wires and fuel filter. It would almost acelerate, before once again falling on it's face. My belief is now that the timing is too far advanced. i retarded it some, and the truck did pick speed like it should. Things were looking up for the old truck breifly until the radiator popped.