Another “help me get it running” thread (1 Viewer)

[Adarcy]

Hi mud,

I’m looking for a bit of help in getting my 40 running again. I believe I’m looking at a timing problem.

I’ve got the engine at TDC, needle on the bell housing is showing the BB. New fuel lines, new carb (I bench set it), verified fuel getting to the carb, new plugs and wires.

Setup the firing order of 1-5-3-6-2-4

A few pictures attached.

The engine just cranks and cranks. If I put a little fuel down the carb throat it will fire up, then die out immediately.

What step am I missing? I feel like I’ve read every finding TDC and distributed thread at this point. Tunnel vision in full effect.

 

[1911]

Sure sounds like a fuel delivery problem. Is your fuel pump working?

Just FYI, the line on the flywheel is TDC, and the bb is 6 degrees BTDC.

Also assuming you know that in a 4-stroke engine, there are two TDC one on the compression stroke and one on the exhaust stroke; you must use the one on the compression stroke of cylinder #1.

But if it runs when you pour gas in the carb, it is almost certainly a fuel delivery problem.

 

[fjwagon]

Well said on the compression stoke. So rotating the fly wheel TWICE ( see the BB the second time) will yield one complete cycle. One way to make sure you are on the compression stroke is remove the valve cover, set it up like you did the first time. Once you see orientation of the valves (some will be closed and others are open. Removed the dizzy and reinsert. And for those who have never done this, a flat screw driver can be used to rotate the slot of the oil pump to match the distributor.

 

[Adarcy]

Hi everyone, i'm finally getting back around to trying to get my 40 running.

We got it to fire up at one point, but couldn't adjust the hei distributer enough (the cap was hitting the engine), so we replaced it with a factory Toyota Distributor, coil, and ignitor from a FJ60.

Fuel pump is definitely pushing fuel to the bowl, i can see fuel spray down the throat of the carb, and i've confirmed i'm on the compression stroke.

What am I missing? With a spray of starter fluid or fuel down the throat of the carb it will start, then die.

 

[Krondor]

This may be a dumb question but when you say you set the firing order to : "1-5-3-6-2-4 ", Are you connecting the spark plug wires from the distributor numbers to cylinder number starting at the front, 1-1, 2-2, 3-3, 4-4, 5-5?

When spray starter fluid down the throat of the carb, will it continue to run as long as you spray fluid?

 

[Adarcy]

This may be a dumb question but when you say you set the firing order to : "1-5-3-6-2-4 ", Are you connecting the spark plug wires from the distributor numbers to cylinder number starting at the front, 1-1, 2-2, 3-3, 4-4, 5-5?

When spray starter fluid down the throat of the carb, will it continue to run as long as you spray fluid?

I believe the answer to your question is, yes. Starting from the front/1st cylinder I have #1 plugged into the #1 spot on the cap which is also where the rotor is pointing with the motor at TDC. Then cylinders 5, 3, 6, 2, 4 plugged in, in that order to the corresponding locations on the cap. My cap is labeled. Picture attached.

Yes, if I keep manually adding fuel it will try to keep running.

 

[Krondor]

As long as it looks like this:

And if you are able to spray fluid to keep it running, you have spark. If you have spark and fuel delivery, it sounds like the next problem is your carb. When was the last time it was rebuilt?

 

[C6H12O6]

Does the Weber carb have an idle fuel cutoff solenoid, similar to the Aisin carbs? If that is not functioning properly, it'll have fuel in the bowl and pressure in the line, but the carb won't keep feeding fuel to let the engine keep running. It would do exactly what it's doing to you with the starting fluid, but die when you stop.

 

[1911]

With a spray of starter fluid or fuel down the throat of the carb it will start, then die.

Still sounds like a fuel delivery problem. Check the float level adjustment in the carb; while you're there, clean out the needle valve seat and needle for the float bowl.

 

[Adarcy]

Yes, that is exactly how it is wired. Carb is a brand new Weber 32/36.

As long as it looks like this:

View attachment 2222491

And if you are able to spray fluid to keep it running, you have spark. If you have spark and fuel delivery, it sounds like the next problem is your carb. When was the last time it was rebuilt?

 

[Adarcy]

Does the Weber carb have an idle fuel cutoff solenoid, similar to the Aisin carbs? If that is not functioning properly, it'll have fuel in the bowl and pressure in the line, but the carb won't keep feeding fuel to let the engine keep running. It would do exactly what it's doing to you with the starting fluid, but die when you stop.

The Weber only has an idle speed screw, air mixture screw, and a fast idle (choke) speed screw. I currently have it at bench setting with the air mixture screw 2 turns out and the idle speed screw 1 1/2 turns in.

 

[C6H12O6]

It has something wired up on the side. That non-OEM greenish wire attached to the plastic round piece is probably for some sort of cut-off solenoid. The purpose (at least on the Aisin) is to cut the flow of fuel through the idle circuit when you turn off the key, helping the engine to shut off quickly. If that circuit loses 12V when running, the engine will die. Similarly, if the wiring doesn't feed 12V to the solenoid when keyed, the idle circuit is blocked and the fuel in the carb can't get to the cylinders. You could sneak some starting fluid down the throat of the carb to get it to start, or even pour some gas in, but as soon as that fuel is used up, it'll die, as no fuel is making it through the carb.

 

[Krondor]

What is the part number for the carb?

 

[Adarcy]

It has something wired up on the side. That non-OEM greenish wire attached to the plastic round piece is probably for some sort of cut-off solenoid. The purpose (at least on the Aisin) is to cut the flow of fuel through the idle circuit when you turn off the key, helping the engine to shut off quickly. If that circuit loses 12V when running, the engine will die. Similarly, if the wiring doesn't feed 12V to the solenoid when keyed, the idle circuit is blocked and the fuel in the carb can't get to the cylinders. You could sneak some starting fluid down the throat of the carb to get it to start, or even pour some gas in, but as soon as that fuel is used up, it'll die, as no fuel is making it through the carb.

That wire goes to the electric choke. An idle cut off is an option for this carb that I do not have. In it's place, one on each side of the carb, are idle jets.

 

[Adarcy]

What is the part number for the carb?

It's a Weber 32/36 DGEV 22680.033B

 

[C6H12O6]

Gotcha. That makes sense. Not having the cut-off solenoid is only really a problem if you're having dieseling/run-on problems.

Air, spark, and fuel. Not much to these motors. I suppose the choke could be closing too far and stopping airflow through the carb, but not likely. Have you verified spark through the plug wires? If you have good spark reaching the plugs, it's time to start double/triple checking fuel delivery through the carb.

 

[Krondor]

Is the carb grounded in addition to having a constant 12v to the choke?

 

[Krondor]

https://forum.ih8mud.com/attachments/weber-trouble-shooting-guide-pdf.675722/

 

[thebigredrocker]

@JohnnyC and @Weber Sarge are Weber Guru's maybe they'll chime in

 

[thebigredrocker]

Have your unhooked the fuel line, set line in a bucket, crank engine for 15 seconds with coil wire disconnected. I believe @Pin_Head has stated you should get a cup of fuel every 15 seconds.