305E won't start, backfires

[Snags]

He's some light reading if you guys are bored:

1963 305E, hadn’t been on the road in 19 years. Previous owner supposedly got it running about 10 years ago but didn’t drive it.

I put in new:
battery
battery cables
starter
coolant hoses
thermostat
water pump
fuel pump
spark plugs
spark plug wires
coil
points and condenser
rotor cap
crankcase breather filter
Holley 4412 carb from Ebay (PO said it should be factory jets and power valve, not sure)
vacuum hose to distributor
fuel filter
gaskets
main seals

I got it running this past summer and drove it about 5 miles to the body shop and back. Then I didn’t touch it for a couple of months. This past December it fired right up and I drove it up on the tow dolly and brought it over to the muffler shop. While I was driving it off the tow dolly it started stalling. But it would start right up again, but seemed to act as if it was getting low on fuel. I drove it into a parking spot and it died again. That night the service tech said he was barely able to drive it into the shop before it totally died and wouldn’t start again. Next morning I show up to pick it up and I put in a couple gallons of fuel. It starts hard, coughs and sputters but won’t stay running. Some times there was lots of black smoke coming out the tail pipes, and a very strong smell of fuel in the air. Every time we tried to start it it ran weaker and weaker until it finally wouldn’t start at all. So we had to push it up on the tow dolly.

When I got home I checked the spark and it seemed to be weak. So I adjusted the points again, and tightened down the condenser screw (which was a little loose), checked the plugs (seemed to be dry) and tried to start it. It would fire randomly while cranking but that became less and less frequent each time I turned it over, until finally it wouldn’t fire. It also backfired nicely out of the carb. I noticed some oil dripping down the block from the head gaskets on each bank, and saw some puffs of exhaust coming out while cranking the engine over. So I towed it over to a mechanic to have him replace the head gaskets and figure it out. It was -15 in Michigan at the time so I wussed out. When he put it back together he couldn’t get it running, and it back fired and he thought it was getting too much fuel through the carb (but he didn’t work on carbs so he did nothing about that). He replaced the plugs, points, condenser and starter again (he never gave me a good reason why the he thought the new ones I had put on a few months ago were no good). After he put all this stuff on it fired right up and we drove it 2 miles home. While driving home it started to sputter, backfire flames through the carb, and finally it died in the driveway and wouldn’t start again.

Had another mechanic friend come over and listen to the truck turning over, complete with flames/backfire out of carb, and he thought it could be a stuck valve.

While looking at the poor spark issue I also noticed the wire connector on the firewall near the coil (passenger side) where the wires from the starter/resistance wire/coil/distributor come through, there is some corrosion in the connector.

Any thoughts????

[66birdman]

Clean that connector, set your valve lash (as best as you can since its supposed to be warmed up first) and then check to see if your ballast resistor wire is working properly. I just went thru pretty much the same thing with my 66 with a 351E. The ballast wire comes from that plug you are talking about, heads down the harness and doubles back to the coil. You cant really find a replacement so you may have to cut it out and replace it with a ceramic style resistor. I could be wrong in your case but thats what fixed mine

[Jeannie]

Snags,

A member requested that I forward the following message to you.

I had something similar on a Triumph TR-6. Misfires, weak spark, smelled of gas.

It was the spring in the distributor cap that holds the button in the cap against the rotor button. It had broken or whatever and wasn't maintaining good contact. The top of the button was carboned up. Clean it and it will be good for a few miles. Repeat, good for a few miles, etc. I replaced the distributor cap and rotor button, good as new.

Could be what you have.

John
'63 Fenderside

[sclor]

Snags:
My recommendation would be to first do a compression check on each cylinder. That will resolve the mechanical issues such as stuck valve, blown head gasket or slipped timing chain. Compression should be over 125 psi on each cylinder.

Report back on what you find and we can take it from there.
Regards,
Steve
New Orleans

[tommyduncan]

Could it be as simple as the float sticking? That is exactly what mine does when it sticks...

The next time you try to start it, whether it starts or not, look down into the carb and see if fuel is dripping into the engine afterwards. I can hear it when mine does it. If it runs for a while then quits unscrew the plug on the passenger side of the float bowl and see if fuel pours out. Use caution of course. Maybe have a hose/fire extinguisher handy just in case.

If any of this proves to be the problem you need to fire the people that work on it because this is a basic Holley problem.

[Snags]

Long over due update:

Switched out the Holley carb and put back on the original Stromberg. It still won't run and back fires/flames out the carb.

Will try compression test next.

Any other thoughts?

[Schroer1962v3000Dump]

I agree with 66birdman I also have had multiple problems with old Ballast Resistors I really like "Accel #150351 Dual Ceramic Resistor around $12" have currently on a 79 Ford Pro Mud Truck and 1984 Charger Bass boat 140 chevy 4 banger and soon my 62 GMC.

You can run a jumper straight from the battery to the positive on the coil to test if the truck will run........BE VERY CAREFUL.... The coil will overheat and blow its top Been there done that. Remember Testing only be quick and disconnect connection asap!!!!

[Irishbleueyes]

Originally Posted by Snags

Long over due update:

Switched out the Holley carb and put back on the original Stromberg. It still won't run and back fires/flames out the carb.

Will try compression test next.

Any other thoughts?

If the engine itself is ok a backfire thru the carb is a lean condition or a problem with the igniton. So changing the carb and the problem is the same its in the ignition. Make sure the engine checks out, if it does then go thru the ignition again.