The other day while drive home runnin about 65, all of a sudden my truck just lost power( not electrical ) rpm's started to drop. Feathered the gas pedal a few times with no help and pulled off out the way of traffic. Motor started runnin right so I went on to the house.
I figured the carb needed cleaning been about 6 months since lasst cleaning. pulled carb off went to town with a can of B-12. cleaned it up real nice inside and out. Put it back on took it out on test drive, all went well no problems.
Drove to work yesterday morning runnnin 45,55,65, and 75 not a problem then and when in town droppin the hammer at lthe lights no problems went for lunch, on the way back from the BK it lost all go power sounded like my truck was a vw beetle. limped back over to shop.
An started checking and trying the following...
a/f ratio no luck, zip tied ele. choke open no luck, checked ignition system ( cap,rotor,wires and timing)all fine no luck.

As of now truck will run fine for about minute or two then it starts trying to die. Towing it home tomorrow

ANY HELP PLEASE!!


Thanks
Tailgater_73F100
Savannah, GA

1973 F100 Custom LWB 302 C.I.D.

 

my '77 302 did that once and i had water in the gas. the gas station in my town bought gas from other stations that had gone out of business at a discount, so the transfer often caused more water to get into the gas somehow. with only one gas station in town, i had to start to buy my gas in the next town over ( 14 miles away ). problem went away with the old gas.


also, you might check your fuel filter. might be just plugged enough to be troublesome, but not enough to completely kill the engine.

just a thought.

 

1)water in gas: bottle of gas treatment (methyl alcohol to absorb water). 2)Failing ignition module; intermittent good/bad firing then finally dies totally; don't know how that relates to Mallory.

 

Based on experience...as that has happened to me in the past...I agree with rainbowATF. Ignition module box might be the problem. In my situation, it would do that lose power so I would pull of the road...give it 15min or so and then the truck would start right up. Turns out that I was allowing it to cool (and didn't even know it).

Hope that helps...

 

sounds like module to me

 

I'm leaning toward fuel starvation. After it dies, move the throttle and see if gas is squirting into the engine - that would tell you if it's running out of fuel. If so, then check the filter and pump.

Let us know what you find...

Marty

 

If it was lean on fuel, that would not explain the weird timing, and if he could put it to the floor repeated times at stop lights, it might be electrical, when those boxes go, they sorta take a while to go. I would change the ignition modules first, then go from there.

 

If it has a Mallory Unilite, it will either fire or not. I have a lot of experience with these. They do not use the factory ignition box, it is self contained in the module. I have never seen one fire like described so I would doubt that the module is the culprit.
I wonder if your gas tank isn;t vented properly and after running at highway speeds, it staves for fuel. The after it dies, the vacuum in the tank is released and fuel flows again.
Maybe try running it with the cap off and see what happens.
Jimmy

 

Sounds like fuel to me, bad gas, tank vent , fuel filter, fuel pump

 

Ok got her to the house thanks to AAA. I just hated to have my truck towed. What a bummer

Now comes the fun work of chasing a gremlins and where to start.

Fuel: I only by Enmark double filtered 93 octane and only on tuesday so I save 7 cents per gallon. We know these babies suck up some fuel. I also did a fuel treatment not to long ago. Our Taurus runs fine, both get fueled up there.

Carburetor: I did notice that when I pushed down on the throttle pump lever I did not get a spray of fuel down it to the main venturi, not more than a squirt I'd say. Going to check fuel pump, make sure that it's feedin fuel. ( just bought that pump too.) Wonder if its arm is hanging up and then it stops pumping and then fall back onto the cam after a brief rest. really need to look more into this area.

Ignition module: Its little over two years old. Spent thirty minutes on hold today, to end up having to end that waste of my companies time before the boss found out. Will be sending a email to Mallory for S&G's tonight. Gotta atleast see what they say.

Gas Tank: Never had a problem before. But I will check all of the vent tubbing.



Thanks ya'll for all the great posts, I just hope I'm able to solve this problem real soon. Cause I gotta ride in my truck man! I'll keep ya'll in the loop. Any more ideas toss them this way.

Thanks
Tailgater_73F100

73 F100
02 Taurus SE

 

Didn't see fuel filter in your list there. Might wanna check it

 

Gonna look there aswell .

sorry

 

It must be the filter or bad gas. Also, go buy (if you dont have one already) a vented gas cap. My 77 was doing the same thing and I drove it home and I had to use a hammer and screwdriver to get the cap off because of the suction. So I bought a vented cap and it solved my problem, I also replaced the filter. Which is due for another change. They are cheap...

 

Seems as if it was the filter, it would be consistant in its engine power loss. My tanks are rusted as we all know. I can drive it ten miles and I can tell you when its gonna shut down on me. The module is mounted on the firewall? Why not space it from the mounting plate. Give it some air underneath, and let it breath more. Sounds like vapor problem to me.

 

Sorry guys for not reporting back sooner. But "I have been gettin' at it like a one legged chicken in cow poop".

Anyways pulled the carb, did a complete rebuild. Found a lot of sedament in it after soaking it in laquer thinner. Also changed out fuel filter.

I'm happy to say that my baby is running great!!!

Thanks for all of the help guys.

Tailgater_73F100
Savannah,GA