All,
I have a 55 f100 that I dug out of a barn earlier this summer. After new coil, points, condenser, plugs, plug wires and fresh gas ... I got it running. Other than a little lifter rattle it sounded strong, and I didn't notice any ugly smoke, etc.

I backed it in the shop, put it up on jack stands and started a gas tank/line and brake system replacement... just to make it safe to drive around while I decide what to do.

Somewhere along the way, it started running very poorly. It got to the point that it backfired/sputtered, and then finally would simply not start.

A couple of weeks ago I dug in and found a bad connection in the ground wire between the points and the side of the distributor (NOT the coil ground, but another that simply connects points to distributor wall). I see 3 wires... points to condensor, points to coil negative, and points to distributor wall. It was this third one that had an obvious break.

I fixed that, and is started right up..... again it seemed to run pretty well. I day or two later I noticed that it would bog down when I gave it gas.... then it started sputtering and backfiring again..... I let it run out of gas, (still no working gauge).

After figuring out that it was out of gas, and putting some in the tank, it did start again, and ran ok, but ran pretty rough... including more backfiring, it died again, and I have not been able to restart.

I was able to get it to try and sputter with starter fluid, but couldn't get it to start.

I've since replaced coil and points again (just in case), but now it won't even sputter with the starter fluid.....

Really seems like a spark issue, but I'm stumped.

I know backfires, etc might be timing issues, but I've done nothing that should have changed the timing. How likely is it that the timing chain jumped or striped under these conditions... again, it was running pretty well, when I started the fuel tank and brake work.

Please give me things to look at or consider. I'm done with the brakes and fuel work, and really hoping to drive her out of the garage soon.

One other note, I'm pretty sure I abused the fuel pump and carb with some nasty stuff coming from the old tank, before I decided my attempts to clean it out had utterly failed. I'd not be surprised if it needs some carb work, but the symptoms aren't leading me to believe that is the main issue ...

Thanks in advance!

 

90% of ignition problems are carb problems. Crap in the carb circuits wil cause what you describe.

 

As you are cleaning/rebuilding your carb, I would check for vacuum leaks.

 

Ditto on carb problems also check fuel filters, some pumps have filter as well as the inline many of us have put in and most carbs have one. I installed the glass inline so I could change or clean as needed. This sounds just like what I had happening.

 

and I'd bet that the plugs are fuel fouled from the poor running

 

Thanks, all. I will work on that..... have never rebuilt a carb....Will research, and see if I can. Thanks again!

 

I'm sure you can do it. The simplicity of the 292 carb is amazing. I was sick from chemo treatment and took the youngest son (16 yrs old) and had him pull it and walked him through rebuilding it. His face lit up when it started and ran so nice.

 

If it back fired any at all it may well
have jumped timing. Easy enough to
check. Does it have a canister fuel
filter on the fuel pump? Most peeps
don't look for one there.
Like was said check to see if the plugs
are fouled. If ya have good spark at the
plugs and they fire but it still won't fire off
with a bit of gas (not start fluid) down the
carb than I would look to a timing issue.

 

Have you pulled #1 plug and got it up on compression stroke and checked to see if the rotor is pointing to # 1 spark plug wire? If it isn't it probably jumped time.
Instead of pouring gas down the carb wet a heavy sock with gasoline and put it over the carb throat and try cranking. Much less chance of a fire if it backfires through the carb. Works good on fuel injection too? If you have a timing light you can tell if it jumped time also.
Elmo

 

Thanks again. Always amazed at the helpful advice given in this forum. I will be re-checking plugs, etc. Couple of (likely dumb) questions...

(1) I can actually see gas squirt into the carb each time I hit the throttle. I'm I wrong in assuming this pretty much eliminates any concerns about clogged, filters, etc preventing gas from getting to the carb? I will re-check anyway.

(2) If it has jumped timing, do I just need to re-time (which I need to figure out how to do), or is something inside also likely striped or broken, etc?

(3) I'll be hitting up you-tube and searches on this forum too, but what's the easiest way to get the #1 cylinder at the top of a compression stroke?

 

Using a wrench on the damper bolt works. The #1 cylinder is the forwardmost on the passenger side. Remove plug, turn engine clockwise with thumb firmly over spark plug hole. The compression stroke will force it off. You can buy a TDC indicator or use a wooden dowel if you need gnat's *** accuracy. Seems plenty accurate though.

 

"I've since replaced coil and points again (just in case), but now it won't even sputter with the starter fluid....."

Assuming you gapped the points correctly did you also replace the condenser? Many of these off shore ones are crap and DOA. If you did replace it with a new one, try putting the old one back in..

You did remember to put the rotor back on? I've made that mistake before LOL.

 

[QUOTE=You did remember to put the rotor back on? I've made that mistake before LOL.[/QUOTE]

Ive forgotten it before, but not this time . Will put the condensor back on...I did replace.

 

If the plugs are to wet it wont fire
under comprehension. Maybe pull all
the plugs and let her air dry over night.
This is a simple system as far as spark and
fuel go. If you have spark, fuel and compression,
and the proper amount of each in the proper order
it has to run. Eliminate these one at a time so ya know
each is doing what it is suppose to do.

I am thinking at this point from what you have said is it has no or
not enough spark at the plugs, flooded? Or it's out of time or both.
You know it is getting gas so next I would make sure the rotor
points to the number one wire at the dizzy cap with #1 cyl at TDC
on the power stroke.

 

I'm assuming that the 55 has a 12 volt negative ground system. I'm concerned that it hasn't popped since you last changed the coil & points etc. Tell us about the wires running to the plus side of the coil. One is powered when you turn the key to the "ON" position. That wire should go to a ballast resistor, then from the resistor to the coil plus. The resistor steps the voltage down a little to around 9.6 volts....the coil won't heat up as much. There should also be a second wire going to the coil plus terminal...it comes from the starter solenoid and provides 12 volts when you are cranking the engine.

One thing to look for...does the coil have a sticker that says "no resistor required"? Those coils have in internal resistor, so your original truck circuit would be reduced yet again inside the coil...so a weak spark.

Pics are good....everybody here likes to look at pics of trucks!!

Dan