The Stovebolt Site Forums The Shop Area Engine Shop Won't stay running

Good Morning Everyone. Been a long time since I've chimed in. I'm working on my 47E, art deco COE. It is all stock, updraft etc. After sitting for about 10 years (running before) I rebuilt the carb, cleaned out the entire fuel system. I got it to fire while the starter is engaged, but it won't keep running, and takes about 5-10 seconds to fire again. I can crank, but it won't fire initially. Only after 5-10 seconds after the last fire. Distributor stuff is new as of 10 years ago, and it is currently on an IV fuel system just to eliminate lingering fuel issues. Coil has a constant 6.6V. Fires up really strong and positive and just dies immediately. Wait just a few seconds and I can do it again. Won't keep going? What can I look for?
Thank you in advance for the help, Tom

Tom,

Good Morning yourself and Welcome back from your long (7+ yr) hiatus!

Since your questions pretty much revolves around your engine operation, I have moved the thread over to the Engine Shop for more on-topic conversation and help from fellow Bolters as it;s the best place for such discussion.

Good luck on you quest to resolve the non-running issue!

Dan

Thank you Dan.

Small update: I believe it to be carburetion. I have a steady 7V at the coil with a battery charger on it. That doesn't change, so in theory, the spark should remain consistent, excepting condencer and coil. Coil is new, and dist components have no miles on them. So I get a little gas dripping out of the bottom of the updraft carb drain hole when it cranks. The pump moves freely, but the sleeve seems to be stuck and I can't get the pump assembly back out. float level is OK.

Providing your fuel pump is ok I hard a problem with fuel starvation in my 46 Chevy. At the bottom of the fuel tank is a valve for draining. That area was plugged in the valve and the rubber fuel line was rotten. Cleaned out the valve replace the short rubber line and has run great ever since. Hopes this helps a bit. Davie

Thank you Davie. I'm actually running a quick fuel can tank to eliminate such things for the moment. BUT as you say that, I'm also testing the fuel pump with an open line, and no fuel is coming out of that either, so I will probably have to address, that exact issue next!

To isolate the fuel pump from the carburetor can you elevate your temporary tank to provide gravity feed to the carburetor and see how it behaves? You need to make sure that the elevated tank is secure and the line to the carburetor is secure so that you don't have a fuel spill. Also need to either be feeding from the bottom of the tank or get a siphon started to get fuel flowing.

I recently learned (from another bolter) that the fuel pump should have sunction at 10-15 on the in and 2-4 on the out. I had a gauge, but they only close $10. You can easily check your pump if someone tries starting it. It should hold for a few seconds.

Might be an easy check to rule that out.

Do you have an inline filter to keep you system clean?

Chris

Thank you guys. Yes, I"m running a temporary gas can above the carburetor, and it is secure enough. I'm not driving it. I will get the actual tank in service before it moves. And for this reason, the fuel pump is not an issue. I believe i'm dealing with something going on in the carb. It is dripping gas out the bottom of the carb (remember it is an updraft) and I actually saw it squirt out once during cranking. I don't understand this. I can imagine flooding, but what would pull the gas out of the throat of the carb. There is a governor also on this truck right above the carb, before the manifold, and it is getting moist. Can the intake suction pull gas out of the carb and up into the manifold in the form of a liquid? Seems excessive. Lastly, this is a different carb, doing the same thing. It is possible both are dirty, or have the same problem, but I rebuilt the first one recently, and the one on there now was rebuilt 15 years ago, parked, got dirty, and I cleaned it out and thought I'd give it a try. Stumped.

Try running the engine on Propane. Take the flame nozzle off a Propane torch, attach a length of rubber fuel line to the tube where the flame nozzle was removed, and attach the other end of the tube to the windshield wiper hose nipple in the intake manifold. Turn the gas valve on a little and crank the engine. If carburetion is a problem the engine should start and run.
Jerry

Do you have the air cleaner on and is it clean? A dirty air cleaner can act like a choke and get liquid gas into the manifold. The gas sprays out in small droplets and takes a bit of time to evaporate. When you saw a squirt, was that when the accelerator pump was activated? That would indicate leakage from a carb gasket.

Ok, first off, thank you for all the replies so far. I do have the air cleaner off.

I'm wondering: As an updraft, it may be expelling gas that isn't needed in a normal way... maybe. In other words, the same thing happens maybe, with down drafts and the gas just flows into the intake... maybe. But back to electrical, I found that the little switch that sits on top of the starter has intermittent power loss because it is loose. I also notice that none of my other cabover trucks have this switch. Do I need it and what is its purpose? This is likely my problem. The starter linkage activates it. The process of activation causes a bad connection. As luck would have it, when I have been testing for proper current, it was good, but it wasn't consistently good, and was dropping current, not just losing it completely. I finally caught it with low current. This was happening, evidently, every time I would try to start the truck. Maybe I'm close to getting this thing going.

With that description, I lean toward the problem being the ignition switch on the dash. Check the switch and the terminal connections and wiring. The starter circuit has nothing to do with the ignition circuit.

I'd say that loose connection at the starter is likely the cause of the problem. It's where power for the ignition switch comes from and if you lose power there, it will cut off the ignition. That could also cause a backfire condition because when the coil loses power it fires the high voltage wire to the distributor. I think if you clean up and secure that connection it should fix the problem.

Thank you guys. I think I agree with you klhansen, and Otto, good call, but I have constant good power to the switch that sits on the starter, so I think the ignition switch is working fine. Additionally, this little switch at the starter is in two halfs that is coming apart and has created weak connections.

And, is that switch (at the starter) were power comes from? I have constant at the coil. It appears that switch receives power from the ignition switch, through the coil, and the switch is between coil and dist. Do I need that little switch at the starter? I'm wondering what it does. I have other COE trucks that don't have it. Can I just do the usual coil hot to the distributor and be done? I've about rebuilt the switch anyway, but I don't see a reason for it.

Tomcoe,

Since your diagnostics have lead towards an electrical/wiring potential problem source, maybe it would be better if this discussion continued (or maybe got a new start) in the Electrical Bay?

It would help if you could take/post pictures of this unusual "switch" you have mentioned that isn't on your other COE's.

Ok I will do that. Thank you!

Does your truck have a stomp starter? Per the 48-51 Shop manual, the Forward Control trucks (is that what they're calling COEs?) have a solenoid that activates the starter instead of the mechanical linkage with the stomp pedal. It looks like the attached. The 48-49 wiring diagram shows starters with a solenoid and a pushbutton to activate the starter. And all the power comes from the battery to a lug on the starter and then to ignition switch, etc.