Last week when I was coming home from the parade in the 52, it started to backfire and miss a lot. It was to the point that I could barely make it home. As I turned on my street, the engine quit and I coasted to my house. I then tried to start it again in order to back it into the driveway and it would only crank over, but not fire. I let it sit for about 10 minutes and tried again. It started. I then shifted into first and it would barely go. I started out in second gear and it moved but very little. It was still backfiring a lot. When I moved it enough to reverse, I put it in reverse and it went into the driveway while still backfiring a lot and very loudly.

Now I'm trying to start it again to see what's wrong and same is happening. It's cranking over, but not starting. It has a healthy crank. There's a spark and the coil is good. Points are good and the gaps were adjusted very slightly. Checked all the plugs and found oil on the first three plugs (counting from the front of the engine). There's plenty of fuel in the carb bowls and fuel pump. Checked all fuel filters and they're clean. Compression is at 80 psi on the first cylinder and 90 psi each on #2 and #3 cyl.

Cleaned the three fouled plugs and the engine almost fired, but not enough to fully start.

Any ideas why it's not firing over and what's going on with the transmission?

 

Did you check coil and distributor? Distributor shifted position? chuck

 

Yes, I did. Coil is good and distributor didn't shift.

 

Check the condenser and get another coil anyway.... those dumb things are bad off the shelf sometimes. My 215 would run great until you shut it off and as soon i you turned the key it would not start, not even fire. If its backfiring it could be timing? did you put a new timing chain on it?

 

Sounds like a timing issue. My suggestion is to remove #1 plug and set top dead center than pull distributor cap and check to see if rotor is in fact pointing toward #1 electrode. As already mentioned it could be a weak coil.

Good Luck,
Paul

 

Ilya,coils often bench-test as being o.k.,but will sometimes crap-out under a load.Do you have a known good spare to swap in?Also, I would, as a matter of course,change the cap and rotor, unless you've recently done that.

 

After being persistant, I finally got the truck to fire.

Here's what it sounds like. Take a look at how rough the engine moves and sounds.

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The truck backfired so much and with such force that it caused the muffler to collapse. There's now a crease in the middle of the muffler.

We played around with the carburetors in order to get the truck started. We've reached a conclusion that it could be the carburetors, but maybe the coil is bad. Even though I'm getting a spark, it might be too weak. I don't have a good coil to swap in for a test. I'll just buy another one. The truck has all new ignition/spark related parts installed a few months ago.

 

sounds like its loading up on gas. Check the timing though. Make sure that you dont have plug wires crossed. I have never had this kind of trouble out of my 215. But as much as a pain in the @$$ those 1904s can be, it would not surprise me if that was the problem.

 

Nice truck and engine detail. If the timing or coil doesn't correct it, possibly an intake or carb leak? a spray of starter fluid around the carbs and a change in idle speed or quality may point to a gasket leak.

 

Just a thought here, is it possible that the timing chain jumped a notch? Maybe that occured when she backfired.

 

That's kinda what I was thinking, ..intake manifold gasket leak. Any # of things could make it backfire..points,cracked cap,sticking valve etc..but if all that is fairly new,and it was running fine all morning..you can "almost" eliminate it. I'd maybe get it idling and spray some carb-cleaner around the intake manifold to head gaskets..if the idle picks up or smooths out for a second or two..your close...too lean a few mixture will cause a backfire ..and of course run like crap..you may have sucked in a gasket..let us know how you make out.

 

I think the more obvious possibilities have been covered, just want to add you'll risk an engine fire if you run without an air cleaner element and get backfiring.

 

Did you try swearing at it ?? kick the tires ? toss a few tools on the ground ? all the usual things ? ... sounds like an ign issue to me...stick finger in plug wire.. have wife crank engine.. if the hood latch draws blood you've got good spark.. heh.. rest of the guys covered all the things to look for..

 

Well, let's start at the very begining. If the truck has compression, is timed properly, is getting fuel and spark it should run.

Judging from what you have said and the video, it sounds like it is only runnung on 3 cylinders and one (either one of the off ones or one of the on ones) is firing intermittently - both early and late.

You say there is fuel and the pump is wet and carb shoots gas when the throttle is opened (accelerator pump works, has gas in the carb bowl). So, a gas problem is out. Carb adjustment is another thing (if front three plugs were the wet ones then the front carb is flooding - that's why the flame up in the video).

You've checked your compression and it's ok so that is out.

That leaves spark and timing. And since this started happening all of a sudden I'm going to assume that something that was ok is now broken.

If this is electrical, it sounds like you have intermittent firing - both early and late. That's usually caused by wires cross talking or being out of order. But since it was running ok the out of order thing is kind of out of the picture. Backfiring out the tail pipe means you are firing way late (retarded) - with the exhaust valve opening. OR gas from the unfired cylinders is being pumped into the exhaust manifold and going off when the hot exhaust from another cylinder exits). So, I would check the timing via the static timing method (stick in #1 and distributor alignment at TDC) to check for the timing chain slip. Then I would check the connections for your vacuum advance - also that your distributor hasn't come loose. (firing way late on one and way early on another because the distributor is now out of cam sync)

Check the front carb for flooding.

Lastly, check that there is no moisture in the distributor or on any of the wires. Check all the electrical connections from the ignition switch to the coil, and from coil to distributor. Check all the wires/connections of the distributor components.

 

Condensers have been mentioned; they cause this kind of problem sometimes, especially on 6v systems.

The other common thing is the wire from the points to the coil that goes under the points plate. I had one fail that would allow the engine to idle fine, but when the vac advance kicked in, it moved the plate enough to short the wire to the case.