The Stovebolt Site Forums The Shop Area The Electrical Bay HELP!

The pic I linked is the timing mark on the fly wheel.

Before I remove the distributor I turn the engine over until the pointer is on the ball like in that pic. I'm able to turn the engine with the fan.

Then note the position of the rotor on the distributor before you remove it. Reinstall the distributor so that the rotor is in the same position.

To add alittle to DADS50, I have a white grease type marker that I use to make 2 marks on the dist before I pull it. Like DADS50 I always like to turn the engine until #1 cyl is @ TDC and the timing mark BB is lined up w/the pointer.
I then will make a line on the dist body and engine side to line them up and then I remove the dist cap and make a mark where the rotor lines up on the edge of the dist. The rotor should be pointing at or nearly at #1 plug wire position on the dist cap.

When I replace the dist and realign those marks up the timing is generally spot on when I recheck it w/a timing light.

re. timing, I've found through trial and error that the original designers/makers of these stovebolt 6's were right on setting the timing to where the BB lines up w/the pointer @ 450-500 rpm.

It's amazing how these engines can still run w/the timing way off....

re. replacing the vac adv unit. It's not that bad. I had to replace mine twice (bad 1st one).
Good luck
Dave

I think this would make a "great" video. I'm more of a visual person! Thanks for the help guys, I'm sure I can do it but MAN it's so much easier the second time, am I right? Another Saturday adventure!

Ah ... DAD ... the man needs a video ...

DAD does have video "skills"

Check your PM

WHAT A LEARNING CURVE! First let me say thanks to everyone's input with this project and in the end I think it was "all" electircal". First the battery and then the coil but who knows for sure. when in doubt "replace everything". Steve H,Bradsfour and most of all DADS50,thanks again. I know I sound a little stupid when I say that when replacing the vacuum advance that I would have to reset the timing! I was having nightmares about replacing this but it wasn't bad at all, until it wouldn't run! Setting the timing without a light is a little different but it works. "Rusty" is running in good form. I'll set the time closer when I get to my buddies with a light. Now on to the brakes, thank GOD they don't need "spark"!!!!!!!

Well, I may have rejoiced too soon. I still didn't go for a test drive until this morning and now I'm back to square one. I drove him up and down in front my house, maybe 1/2 mile back and forth and on the third pass, he did the same thing as before I started replacing stuff. It just won't take the fuel. It cut off but would start back up but when you add throttle it acts like its not getting fuel. My driveway is pretty steep and when it did start as soon as I got on the steep grade it would cut off.

Let me just recap what I've done so far starting with the fuel.
1.new vented gas cap
2.drained the tank and replaced fuel (new tank)
3.new fuel filter before fuel pump
4.new fuel pump
5.new fuel filter before carburetor
6.professionally rebuilt carburetor
7.closed vacuum to wipers

On the electrical side
1.new battery
2.new coil
3.new condenser
4.new distributor cap and rotor button
5.new points
6.new plugs and wires
7.new vacuum advance
8.reset timing
9.new voltage regulator

No use to do brakes until this is resolved. Thoughts??

Loose wire on the ignition switch? Maybe try a direct wire from battery to coil + with truck wiring temporarily disconnected?

I'm not sure I follow. so disconnect the switch?

disconnect wiring from truck to coil. Then just hot wire the coil.

I hope I explained myself. It will sit and run all day. It's just after it "drives" for awhile that it acts like it can't get the gas but I'll try it.

He started right up. should I rode test it this way?

fuel system problem rather than electrical ... how 'warmed up' is it when it can't climb the drive? are you using the choke at all? have you checked for vacuum leaks around the carb/manifold? tried bypassing that filter before the pump?

Bill

5-10 minutes idleing. I use the choke only to start and then off. There was a vacuum leak to the wiper motor so I pulled that hose and blocked the line to the manifold/carburetor. He was doing this before I added that filter. Both bowls have fuel.

I agree with Bill it sounds like fuel. Sitting and running at idle means you have the bare minimum available nothing more.
Even pro's have been known to get the float setting off... I've experienced similar symptoms due to float issues.
Just curious, Will it idle when sitting at the steep incline? And Facing up as well as downhill?

I know I'm bits and pieceing this thread together but it did the same thing with the old carburetor. Same issues with old everything as with new everything. Could a short somewhere be doing this? When I first took him out, he's pulling like crazy, tons of go! Sucking down fuel like brand new and after a few minutes he's done, just like you pulled the plug. I don't get it.

what do you guys think about fuel sending unit. that's the only thing I haven't touched.

the sending unit has zero to do with how it runs [unless it tells you there's gas when it's empty ], I say definitely a fuel problem, unless you have some electrical ignotion connection that 'opens' when it gets hot and then immediately makes contact again so the truck restarts easily - as CASO says, the engine just isn't getting strong enough fuel flow ... have any rubber lines in the fuel supply line been changed out for new? internally deteriorated hose can collapse and limit flow

Bill

I do have one rubber line left that's not new. What the hell! I'll try it. What electrical connection would be open when it gets hot?

Years ago with my '64 1/2 ton pickup, I had a problem with Wix fuel filters. They would plug with the finest little stuff. Truck would start and run fine, then starve out at higher load/rpm. Switched to cheaper brand filters and problem gone. Maybe take filters out of system and try road test?

thanks. I'll try anything at this point. These are the clear plastic ones and you can see clear fuel inside but who knows.

As your troubleshooting I find it best to tackle one issue at a time to help determine the problem.

change one component and test..

If you by pass the ignition, test and see if the problem still occurs. If it still occurs you've eliminated that part. If there was a loose connection in the ignition it may not show up until the truck was moving

If you remover the filter, test ...when you replace the filter make sure it's reinstalled in the correct direction.

You will get this solved

Sometimes when forcing a rubber hose over a metal fuel line a little flap of rubber is created, sort of a "one way valve" Check to be sure you can blow thru fuel lines both ways. I remember this happening to a friend of mine years ago. You got us scratching our heads here!

Jim911

Step back and take a couple deep breaths.

It still comes down to the basics:

Fuel, Air, Fire, Compression, Timing, Exhaust

You need to accumulate some real time information.

Hook a timing light to any plug. Put the light in the cab or tape it to the cowl and tape the switch on.
Drive the truck until the problem starts and watch the light. If the engine dies but the light is flashing regularly until the engine stops turning, it's not ignition. If the light starts to skip or stops completely before the engine stops turning it is ignition.

Do you have a manual choke? If not connect one temporarily.
When the engine starts to break down, start pulling the choke. If it gets better, it is going lean. If it it gets immediately worse, it has plenty of fuel and you are flooding it with the choke.

Hook up a vacuum gauge and run it into the cab. As soon as the engine starts to act up watch the gauge. The changes in vacuum can diagnose multiple problems. There are trouble shooting guides on line that show pictures for all of the conditions.

Using information to eliminate things is a lot less expensive and more successful then guessing.

There are other on the road tests if these don't find it.

Here is a link to vacuum gauge reading diagnostics.

http://www.classictruckshop.com/clubs/earlyburbs/projects/vac/uum.htm

Thanks guys. As usual I'm the weekend warrior so I'll have to wait until Saturday. I do have a manual choke Jim and as soon as it starts to die I pull it and it will keep running but only for a second. It will then start right back up but not keep running.

I also need to borrow a timing light and vacuum gauge.

Just a note on the choke. If you pull the choke most of the way or all the way out, the engine can go from too lean to too rich in 2 seconds.

If you ease the choke out and it gets better, you can move it a little at a time out or in to keep it running. This would tell you the problem was from the carb to the cylinder.

The choke would only help for a second or two if there was no fuel getting to the carb because as soon as the float bowl was empty there is nothing to run on.

The vacuum gauge and timing light can eliminate lots of things fast.

Good luck

One other thing that to me seems strange and I already PM'd DADS50, sorry DAD I know I'm wearing you out but you can almost mark off the distance you can drive before it cuts out. It seems like or maybe I'm grabbing at straws but it only does it when it gets good and hot. Could there be a connection?

I'm sure it doesn't feel like it, but you are lucky you can repeat the problem so consistently. I would write down the tests in a notebook then run through them and write down the results. I would try not to jump to the ah ha moment too soon. Testing is faster than fixing since you can repeat so quickly. Let me add another. When it starts to crap out throw it into neutral and take your foot off the gas, essentially get back to the idle state.

Dennis

And they wonder why I drink! Well let me give you an update on today's hits and misses. I thought once again I had found the problem. I deleted the filter before the carburetor and put everything back like factory with hard line from fuel pump to carburetor. I also eliminated all but 2-2" fuel hose lines on either side of the filter before the fuel pump. Just for curiosity sake I looked at the in and out on the fuel pump and saw what I thought was debris, nope. I removed the pump (new) though just to make sure and when I did I noticed the actuator arm was barely scratched from the multiple times I have run it at idle and road tests.

I thought, I've got it now it's the fuel pump and after reading various threads over the past month thought all I need to do is weld a little extra on to make contact because the pump itself tested good, plenty of pull and push!

I buttoned everything up and as usual it started right up with a couple of spits. I reset the timing (I think the hardest thing there was painting the BB indention) and it idled and ran perfect. Then I grabbed my vacuum gauge with chart supplied by Jim Sears and everything was looking good. between 18-22 in the green and no burps. Under full throttle it would go to zero and come back. I felt like this was okay for now.

Even though it's 27 on the mountain today, I thought what the hell, let's do this! As soon as I got situated and ready to pull out of the garage, I got backfiring through the carburetor. Geese Louise! I went back and made sure everything was tightened down and checked the timing again. DEAD ON THE MONEY! It will be warmer tomorrow, so until then, I'm drinking a beer!

I think "RUSTY" will be appearing on eBay any day now!

Hi, Jim, I have read this 2 page post ( while having a beer ) and see that you have not checked the valve clearances yet. Tight valve settings will cause the problems you are having, also the valves may be sticking when hot. One test that you could do is a compression test cold , then run the motor till it will not start and then do another compression check. If it is a lot lower you have a valve problem. Factory settings are, IN .006-.008 set when motor has been driven for at least 30 min., EX .013-.015 set at the same time. For cold settings, start at about .015 IN and .020 EX, then drive 30 min.,reset valve clearances to hot settings. Remember everyone, a motor needs 3 things to run, Spark, Compresion, Fuel. And last but not least Have Fun. Brian

thanks. that actually is the plan for tomorrow. I come from a long line of farmers and they all had these trucks 3100/3600/3800. I learned to drive in a 53 at 9 years old and never ever remember my Dad, my Granddad or any of my Uncles jumping through all these hoops! Times were simpler then!

Jim911

While you are sitting by the fire and enjoying a few beers, we can go over a list. Concentrating on the carb back fire.

Reasons for carb backfire listed in the order they most frequently occur.

1. mixture too lean
2. timing too far advanced
3. spark plug wires in the wrong order
4. intake valve(s) sticking open
5. spark occurring at the wrong time
6. poltergeist
7. other

Before we make a list of reasons for each, a few questions about today.

A. The engine was running without shutdown and restart before you went to drive out?

B. You opened the garage door and let in 27 degree air?

C. You put the clutch in and put it in gear?

D. You started to move the truck?

E. At which one of these points did the backfire begin?

F. Did the engine continue to run after the backfire? If so was it smooth Between backfires?

G. You didn't leave the vacuum gauge connected?


The answers to these will establish the time line of the problem. Then we will look for the zebras.

A. Purring like a kitten!
B. Yep
C. Yep
D. Yep
E. When I added throttle
F. Yep, one big bang and settled right back down. As long as you "ease" the throttle, you're ok.
G. No

Actually great.


Did you put the air cleaner back on?
Do you have manifold heat?
Did you try pulling the choke out 1/3 to 1/2 and moving it again?
Did you read the vacuum from the vacuum advance port?

This instance is not caused by fuel supply to the carb so forget about everything up stream of there.

Things that happened between running good and carb backfire

(Assuming)you disconnected the vacuum gauge and re connected the vacuum advance.

1. the engine was warming up.
2. the intake air dropped below freezing
3. you put a load on the engine and opened the throttle valve
4. the engine ran smooth when the load was removed
5. the engine ran smoothly when the butterfly is opened slowly

Yes, the air cleaner was back on.

Good and hot, so hot I had to put a glove on to add throttle by hand before I jumped in the driver's seat.

No I didn't

No, I read it from the wiper side.

OK, good.

I would suggest you reattach the vacuum gauge and put it where you can can watch it from the cab when you drive.

1. lean mixture

Accelerator pump not working
Main jet too small or damaged/dirty
Float set too low
Vacuum leak (appears you ruled that out)


2. Timing

Forget about timing marks - set the timing with the vacuum gauge.
Vacuum advance diaphragm bad (you checked that)
unusual problems-
Mechanical advance sticking, bad/missing springs
Vacuum advance sticking

3. crossed wires
I know it sounds insulting, But I once had to look at a Mustang running in SCCA events. It was a almost impossible to start but once running it was finishing in the top 5. I found 2 spark plugs wires were crossed. Swapped them and it started fine and finished 2nd.

4. Sticking valves (or too tight)
The vacuum gauge will show this if it is intermittent (of course the backfire will screw it up for a second)or comes on when hot.

5. spark occurring at the wrong time
Cross fire can happen when spark plug wires with weak insulation are running parallel (in a bundle)and the spark can jump to the wrong plug.
Cracked or dirty distributor cap arcing to the wrong plug.
Actually found a tractor engine that had so much carbon in the combustion chamber that when it was hot the fuel mixture would ignite on the intake stroke from hot spots on the carbon and backfire into the manifold.

1. I'll check the float. trust me, everything in this fuel line is clean/new/open.

2. vacuum advance is new and new line. Not sure how to set it with vacuum gauge.

3. trust me, If I ever get him on the road, the plate number is going to be 153624!

4. I've never adjusted valves but tomorrow, it's on.

5. Everything in the electrical line is new and also in the fuel line, beginning to end.

It does sound like everything has been replaced or checked carefully.
So we have to look for the odd detail if you don't believe in poltergeist.

After you set the valves, let the engine warm up and set the idle as close to 500 rpms as possible.

Attach the vacuum gauge to the wiper port.

Leave the vacuum advance connected.

Loosen the distributor port and turn the distributor until you get the highest possible reading.

Then back the distributor off 1 inch of vacuum and tighten the clamp.

it is probable that the RPM will have changed so the idle is higher. Reset the idle to 500 and repeat the timing process again.

This time the idle shouldn't change.

Timing is now optimum.

An alternative method calls for removing the vacuum advance, running the engine around 2400 rpm and setting the highest vacuum there.
I have not found this to be as reliable.

As far as new parts go, I've found so many over the years that were bad out of the box that I treat each one like it is potentially faulty.
I was asked to check a car that hesitated badly any time they stepped on the gas. It had a new carb installed.

I found the accelerator pump wouldn't work. Tore it down and finally found the passage between the float bowl and pump chamber wasn't there. There was an opening in the proper place in the bowl but it only went a couple 32nd's and ended.

You never know.