ok so...

I was in the process of replacing the exhaust donuts, and i had wrestled with them for a while and my dad said "should we just take it to the muffler shop?"

normally i would say no way, because it's my truck and i wanna do the work on it. but for some reason i thought "hey, we get to drive it with no exhaust past the manifolds, it'll be loud as hell." so we went to the damn mechanic, and he got it all fixed up then diagnosed more problems and all that mechanic stuff...

And then, we were driving it home, and all of a sudden it kept cutting out on us. we've owned it for two months and we drove it maybe 5-6 times. it ran perfect everytime. then we were on a road and my dad kinda slowed down and then he put it back in 3rd. it revved up kinda high and then it cut out some more. we stopped at whataburger. when we got back on the highway, we got up to about 50 and the engine started stalling out again. my dad took off the gas and about 3-4 seconds later it backfired big time. It put out soo much smoke and we pulled off on the side of the road for a minute. when we started it up it was smoking for a second, it was a dark brown color of smoke. my dad held it at like 1500 rpms, since it may have been flooded or something. then we continued home and in the next 2 miles or so it cut out at least 4-5 times.

I definitely won't be going to a mechanic again. but anybody know what happened? i think when he down shifted it flooded, then it backfired and all that gas was in the exhaust pipe and lit up. Or maybe something blew up like an exhaust valve. maybe driving it with no exhaust past the manifold was a terrible idea. i dont know, i looked under the hood and didnt see any fresh oil or anything. As far as oil goes, we changed it recently, and before that it had all the oil left from only god knows how long.

Thanks in advance, you help would be greatly appreciated
BTW, im 15 and kinda knew to this stuff so i may or may have asked some dumb questions.

 

im no expert, but maybe you burned up the valves by revving it with no exhaust.

 

thats what i was thinking. hmm that was such a dumb idea to drive it with out the exhaust, im pretty angry at myself

 

Could be it's getting too much gas. Might be the needle and seat or accelerator pump in the carb. I don't think the mechanic had anything to do with it. You had exhaust on the way home right? Do a compression test and go from there.

 

yea i had the exhaust on the way home. another factor is i usually start it, and i just pump it twice then turn it over and it fires right up. my dad turns it over and continuously pumps it, i would guess that floods it a little.

does getting too much gas lead to stalling and backfiring? do you think we burnt a valve when we had no exhaust on? we didnt really rev it that high w/o exhaust, just drive it.

thanks for the help man.

 

and it wasn't having this problem before we took it to the shop.

 

If an engine is running rich you usually have a backfire thru the exhaust. Running lean, backfire thru the carb. My guess is the acc pump failed. Had it happen to me once. It flooded the engine so bad it left me stranded. Easy to change on the front of the carb if it is a 2 bbl.

 

thanks for the info man i'm feeling better about this. what is the acc pump?

 

Its in your ignition. Take a test light and hook it to the negative side of the coil then take a jumper lead and hook that to the negative side of the battery and to the probe end of the test light. Run the truck until it starts to back fire.

If the light flashes continually while it back fires then you have a bad coil if it does anything else then it is something in your primary ignition, Ign module, Pick up coil, etc.

Its not your accelerator pump because your accel pump has nothing to do with steady stay cruise. Its not a burnt valve because it doesn't do it continuously.Whats happening is your ignition is cutting out and allowing to load up with fuel and when the ignition lights up again so does the extra fuel.

What your doing with the test light is watching the ignition tell the coil to fire hence why if the light stays flashing its the coil.

Just a little education for ya

 

FEman72,
Start simple:
1-Check/change fuel filter (starving for fuel sounds like your problem).
2-While filter is off, remove coil wire and hold a bottle or something over the end of the fuel line and crank the engine to check that the fuel pump is working. A fule pump pressure gauge would be even better, if you have one.

How far did you you drive "uncorked" to the muffler shop? If less than 20-30 miles/minutes it shouldn't be a problem.
Gene

 

I ment to say run the truck till it cuts out not back fires. Sorry

 

Its not starving for fuel. Its flooding!!

 

Go to this link....https://www.ford-trucks.com/forums/8...ge-needed.html It has a picture of the front of a 2 bbl carb. Just to the right of the fuel filter is the accelerator pump. There is a lever on it and attached to it is a rod that goes to the throttle linkage. It is held in place by 4 screws. Remove the 4 screws and out will fall the diaphragm and a spring. Get the numbers off the carb and go to the parts store and get a replacement. I think it is less than $10. Can't remember where the numbers are located on that carb.

 

In the 2 months that you have had the truck what have you done to it, tune up or change plugs?? It may be due for a tune up if the PO didn't before you got it. And does it have a points and condenser ignition or electronic ignition?

 

one factor i haven't said yet, i have electronic ignition.

and another theory is that it rained today and my dad says the water may have gotten inside and causing shorts and firing out of order.