2 weeks ago I got in my truck and started it and took off then about 500 feet later it backfired through the carb. I didnt think nothin of it just thought it was cold or somethin like that. So I keep drivin and I notice that it wont accelerate at all untill it gets up to 2400 rpm then it runs normal. I tried to drive it around and see if it quit and it kept doin the same thing. So I called my dad the day after and he thought it was the fuel pump so I looked at the inline filter and it had a bunch of rust in it. So I changed the filter and no difference it wont rev up very good and wont accelerate. So I call my dad back and he asked me if I filled up the truck when the tanker was at the station and I said ya I did, he says it stirs up the crap in the stations tank and the pumps suck it up and right into the truck. Then he says take off the fuel line and filter it through a rag into gas cans a couple of times(there was only about half a tank) and put two filters in a line before the carb. So I did that and no difference but there was a spot of rust on the rag where ever the gas hit. So I limped it out to his house and we changed the fuel pump and cleaned out the carb which is brand new and nothin looked bad inside so I put it back together and put it all back on the truck and same thing, wouldnt run worth a crap. So I threw on an old carter that was on the truck when I bought it and no difference. So we put a holley electric fuel pump on and same thing even with 5 psi. We will try 6 or so tomorrow and see. I pulled the number 1 and 5 plugs and they were mostly white with a little brown. I know white is lean but dont know why its changed now it used to be too rich. The coil is also the old one dont know if it matters or not. We really need help on this one and are both stumped. Thanks Dan

 

Check the timing; it sounds like the chain could have jumped a tooth. Ohm out all of the plug wires. Resistance should be no more than 7,000 ohms per foot. If timing and plug wires are good, run a compression test. Carbs and coils are often blamed when they're not always the culprit. Since you've tried 2 carbs and 2 fuel pumps and got the same results, investigate the other stuff I mentioned first.

 

Would it jump on a motor that barly has 2000 miles on it with a double roller? It has accel wires and new cap with new rotor les than 6 months old.

 

No one can answer that; that's why you need to check. Speculation and assumption are no match for measurements and objective diagnosis. If you don't check things out, you won't find the problem. Check the timing, ohm out the plug wires, and if all else fails run a compression test. You have an intake backfire, which means that the combustion happened while an intake valve was still open. That's why I mention to check these things. I'm not saying those 3 things are going to nail your problem, but step-by-step process of elimination will. Nice looking truck by the way.

 

Hey thanks alot it still has the usual ford rust but its more of a beater than a show truck. I will have my dad check that stuff out im out at moms right now and dad is an hour away so Ill be out there next weekend but hes workin on it while im gone.I really apreciate it when somebody gives me a compliment on it. Around home people dont like it cause its old and loud.

 

Sounds like timing to me too. Might want to check your vacuum advance on your dist. Maybe the diaphragm is bad. Looks like a pretty sweet truck to me. I like them loud too.

 

Ditto that, it's difficult to diagnose over the internet but i'd suspect your vacuum adavance, keep us posted.

 

Could the dura spark box be failing? I had one fail that acted kinda like that.

 

Is the duraspark the box on the inner fender up by the cab on the drivers side? I dont have points anymore and dont know what brand the kit is. It seems to work fine on the ignition department I didnt put it on one of the POs did. So I really dont know alot about the ignition we just checked the gear and slop in the distributor and it was good so we put it in. Im just kinda disgusted right know cause its a new motor and it took us a few tries to get it right. My dad dont think its the timin bein a dual roller chain but we will check it im goin out there today to see then ill stay out for awhile to fix it.

 

Alright im out at dads and we threw a timin light on it and it was set at 6 deg. advance when we first put it in. I was in the cab and dad was under the hood with the light he said it was about 10 or 15 degrees retarded. Now it runs better and I can actually drive it. Thanks for all the input I shoulda just went by what you guys said in the first place. Dad dont like the forum and he wants to figure everythin out for himself or throw parts at it. It does still have a hesitation in it and I think it might need a little more fuel pressure or a little more advance on the timin. Why do you guys think it jumped time like that and so far. When we put the cam in and tried to put the pin in for the gear it was loose so we put blue loctite on it and some sealant to try to keep it in there, dad was kinda in a hurry to get it goin again and out of the driveway. Could this be the reason why it jumped time?

 

Are you talking about the pin for the distributor gear? Also, it's possible the distributor hold-down bolt wasn't tightened down, and it let the distributor walk. I've seen that happen before.

 

No im talkin about the pin that holds the timing gear to the cam and fuel pump eccentric. The distrubutor bolt was tight cause I saw dad break it loose.

 

Well we got er whipped and runnin again it turns out it was the vacuum advance on the distributor. I thank all of you guys for helpin me out with this, I was just about to give up on it.

 

Good to hear! Btw, thats the same paint scheme my beast has-except yours seems to have more paint, lol
Another thing to check, after its sat awhile-pop the distributor cap off, and see if your advance moves-sometimes they dry up and seize-just grab the rotor and turn it counterclockwise(advance)-shouldnt take alot of pressure and return nicely. Watch greasy fingers on the rotor tho-or it will cause more problems.

 

Hahaha mines missin some paint on the hood you cant see it in the pic but its down to the primer in spots. If it gives me any more problems I will look into that. Also im havin a little trouble dialin it in (timin and fuel pressure) Ive got a cheap dial regulator that goes up to 5 and a half psi. Ive set my timin at 6 degrees advanced with the regulator turned up all the way to 5 and a half. I am still gettin a sputter at RPMs just above idle when I start out. Is it too much fuel or not enough? We know how to get it close enough to drive it but we dont know how to dial it in really good.