Holley 2300 Conversion woes

[AngryPirate]

So, I got a Factory refurb Holley 500 2bbl 4412S wallered out the opening a bit to match the opening on the bottom of the new Holley carb adapter plate, torqued everything to spec, hooked up the fuel, throttle linkage, choke and vacuum advance to the dist.

It runs like ****, when I can even get it running. When it does run, the vacuum advance runs the RPMs up super high. I adjust the dist to lower the rpm but it seems to be slightly misfiring. All other vacuum ports are plugged.

I've tried everything... setting the idle mixture screws out 1 1/2 turns from turned in all the way, messed with the ignition timing and I think I smoked my coil (and I'm sure my starter is about to go too).

It ran decently with the Stromburg WW2 carburator.

This is MADDENING.

Any other ideas?

The only other thing I can think of is the timing chain skipped at some point? It there an easy way to determine the initial timing of correct?

Thanks for any help.

[James]

Originally Posted by AngryPirate

It runs like ****, when I can even get it running. When it does run, the vacuum advance runs the RPMs up super high. I adjust the dist to lower the rpm but it seems to be slightly misfiring. All other vacuum ports are plugged.

We need to make sure your carburetor is setup correctly.

First, do not connect the manifold vacuum to the distributor, keep the port plugged.

Second, Start the engine and set the fuel level. The level should be to the bottom of the hole (remove the plug on the right side of the carburetor fuel bowl to do this). If it is not correct, loosen the screw on top of the bowl and turn the nut under it. Clockwise turning the nut (be sure to hold the screw still once it is loosen, don't turn the screw while turning the nut) will lower the fuel level and counter-clockwise will raise the fuel level. Once the level is set then tighten the screw while holding the nut still. After it is set reinstall the plug on the right side of the fuel bowl.

Set your distributor, idle speed, and idle mixture. I beleive the Stromberg carburetor provide ported vacuum to the distributor (I don't remember for sure). I can take a look at my old Stromberg carburetor later to make sure.

If you connect manifold vacuum to the distributor it will run too fast at idle and you might not be able to idle it down. I had modified my carburetor base plate and gasket to allow using the port vacuum like the Holley 4150/4160 carburetors, it has a fitting coming out of the right side of the metering block. The vacuum fitting on the back of the carburetor is manifold vacuum. The fitting below the choke I think it does nothing (I could be wrong on this part).

The other guys on this forum could have some other answers that might also help you.

[AngryPirate]

Originally Posted by James

We need to make sure your carburetor is setup correctly.

First, do not connect the manifold vacuum to the distributor, keep the port plugged.

Second, Start the engine and set the fuel level. The level should be to the bottom of the hole (remove the plug on the right side of the carburetor fuel bowl to do this). If it is not correct, loosen the screw on top of the bowl and turn the nut under it. Clockwise turning the nut (be sure to hold the screw still once it is loosen, don't turn the screw while turning the nut) will lower the fuel level and counter-clockwise will raise the fuel level. Once the level is set then tighten the screw while holding the nut still. After it is set reinstall the plug on the right side of the fuel bowl.

Set your distributor, idle speed, and idle mixture. I believe the Stromberg carburetor provide ported vacuum to the distributor (I don't remember for sure). I can take a look at my old Stromberg carburetor later to make sure.

If you connect manifold vacuum to the distributor it will run too fast at idle and you might not be able to idle it down. I had modified my carburetor base plate and gasket to allow using the port vacuum like the Holley 4150/4160 carburetors, it has a fitting coming out of the right side of the metering block. The vacuum fitting on the back of the carburetor is manifold vacuum. The fitting below the choke I think it does nothing (I could be wrong on this part).

The other guys on this forum could have some other answers that might also help you.

"remove the plug on the right side of the carburetor fuel bowl to do this" - I'm guessing you meant the passenger side of the vehicle?

"fitting below the choke I think it does nothing" - I believe the documentation said the one below the choke is meant for timed ignition vacuum. See diagram of carb attached. Perhaps I need to use full manifold vacuum?

You're suggestion about the float level seems like a great starting point since it's the only place I hadn't yet explored. I assumed the factory setting would be reasonable but I am ignorant and it seems I should check this.

My Stromberg WW2 had a vacuum port on the back.

Thanks a bunch!

[James]

Originally Posted by AngryPirate

"remove the plug on the right side of the carburetor fuel bowl to do this" - I'm guessing you meant the passenger side of the vehicle?

"fitting below the choke I think it does nothing" - I believe the documentation said the one below the choke is meant for timed ignition vacuum. See diagram of carb attached. Perhaps I need to use full manifold vacuum?

You're suggestion about the float level seems like a great starting point since it's the only place I hadn't yet explored. I assumed the factory setting would be reasonable but I am ignorant and it seems I should check this.

My Stromberg WW2 had a vacuum port on the back.

Thanks a bunch!

When referring to left and right, it is viewed as if you are sitting in the driver seat.

My spare carburetor and the one on my truck does nothing. My "Timed Spark Vacuum Port" (what I called ported vacuum, get its vacuum from the venturi and not from the intake manifold) is where it says (most model in your picture) after I modified the throttle plate and gasket.

The one under the choke need to be checked by running the engine at idle and see if there is vacuum. For "Timed Spark Vacuum Port" (ported vacuum) there should be no vacuum. Opening the throttle to a high rpm you should feel the vacuum build. Using a vacuum gage make this an easy check.

I always double check the factory setting on a carburetor. To many times it was out of specs. Running rough is a sure sign of too high of fuel level. A quick check, (if you can keep the engine running) with the air breather off of the carburetor, look down into the carburetor (with choke wide open). At idle there should be no fuel coming out of the boost venturi. If there is, fuel level too high. Beside every engine is different. Working with recondition parts is the same as a use parts. You don't know it life history of the part. The carburetor that is on my truck were old unit that a friend gave me that had been laying around for years. Now it as good as new.

[AngryPirate]

[QUOTE=James;78148/]
Thanks for the clarity and the wisdom.

The fuel level was indeed quite low.
That has been addressed.

Now to figure out why my coil isn’t sending out any spark (old one started doing this yesterday and new one I picked up today is behaving the same).
The + side has current and the neg has current when ignition on.

There are 2 wires going into the + side but only one has current. I suspect that is normal since one likely goes to the starter solenoid?

I’m going to have to pull out a wiring diagram and do some hunting.

Thanks again!

[James]

[QUOTE=AngryPirate;78150]

Originally Posted by James;78148/

Thanks for the clarity and the wisdom.

The fuel level was indeed quite low.
That has been addressed.

Now to figure out why my coil isn’t sending out any spark (old one started doing this yesterday and new one I picked up today is behaving the same).
The + side has current and the neg has current when ignition on.

There are 2 wires going into the + side but only one has current. I suspect that is normal since one likely goes to the starter solenoid?

I’m going to have to pull out a wiring diagram and do some hunting.

Thanks again!

+ side is correct, one wire to ignition switch and the other side to the starter. The - side goes to the distributor.

Having voltage ≈12 Volts on the + and - is normal with the points are open. With the point closed, you will have ≈12 Volts on the + and almost nothing on the -. Keeping the key on and the point closed the voltage will slowly start to drop because the resistor wire (which is located between the firewall and the coil) is heating up reducing the power to the points.

Be sure to set the point gap to .019" new points and .016" old points. With the points follower on top of the lobe. If you don't have a set of point feeler gage, you can use a business card, it will be close enough to get it started. An easy check (but be careful you can get shocked), pull the coil wire out of the center of the distributor cap and position it close to the body ground. Be sure the point is close (between the lobes in the distributor). Open and close the points arm (using a flat blade screw driver only on the arm and do not touch the screw driver on the lobes or any other metal parts) and you should see a good spark coming off of the coil wire with the key in the run position (engine is sitting static, not running). Also make sure the screw driver has a good handle on it (shock hazard) and don't touch the shank while working the points (shock hazard).

[AngryPirate]

[QUOTE=James;78158]

Originally Posted by AngryPirate

+ side is correct, one wire to ignition switch and the other side to the starter. The - side goes to the distributor.

Having voltage ≈12 Volts on the + and - is normal with the points are open. With the point closed, you will have ≈12 Volts on the + and almost nothing on the -. Keeping the key on and the point closed the voltage will slowly start to drop because the resistor wire (which is located between the firewall and the coil) is heating up reducing the power to the points.

Be sure to set the point gap to .019" new points and .016" old points. With the points follower on top of the lobe. If you don't have a set of point feeler gage, you can use a business card, it will be close enough to get it started. An easy check (but be careful you can get shocked), pull the coil wire out of the center of the distributor cap and position it close to the body ground. Be sure the point is close (between the lobes in the distributor). Open and close the points arm (using a flat blade screw driver only on the arm and do not touch the screw driver on the lobes or any other metal parts) and you should see a good spark coming off of the coil wire with the key in the run position (engine is sitting static, not running). Also make sure the screw driver has a good handle on it (shock hazard) and don't touch the shank while working the points (shock hazard).

So, I haven’t had points in the distributor for years. I have the Pertronix electronic ignition, which now that you mention it, could’ve burned up.

Thanks for the knowledge you’re dropping on me and onto the forum.
It makes me want to switch back to points.

[James]

[QUOTE=AngryPirate;78159]

Originally Posted by James

So, I haven’t had points in the distributor for years. I have the Pertronix electronic ignition, which now that you mention it, could’ve burned up.

Thanks for the knowledge you’re dropping on me and onto the forum.
It makes me want to switch back to points.

See if there is a troubleshooting information for your Pertronix Ignition Unit. It should help. I know there is other guy on this forum that use this type of ignition unit, they might be able to help you. I am using a bullet HEI distributor on my 305 V6.

Are your ignition wires fairly new? I know back in the day when using carbon wires they would wear out, by enlarging the gap within the wire. Mostly on the sparkplug ends (due to accessing the plugs for maintenance), killing one cylinder. This could also happen on the coil wires, killing the whole engine.

Just to see if you are getting any sparks from the coil through the coil wire. You can use a jumper wire with one end connected to ground and momentary touch the coil - (with the ignition on). The coil wire should spark to ground (shock harzard). Might not be a great spark because there is no capacitor in the ground circuit.

[aphaynes]

[QUOTE=James;78160]

Originally Posted by AngryPirate

See if there is a troubleshooting information for your Pertronix Ignition Unit. It should help. I know there is other guy on this forum that use this type of ignition unit, they might be able to help you. I am using a bullet HEI distributor on my 305 V6.

Are your ignition wires fairly new? I know back in the day when using carbon wires they would wear out, by enlarging the gap within the wire. Mostly on the sparkplug ends (due to accessing the plugs for maintenance), killing one cylinder. This could also happen on the coil wires, killing the whole engine.

Just to see if you are getting any sparks from the coil through the coil wire. You can use a jumper wire with one end connected to ground and momentary touch the coil - (with the ignition on). The coil wire should spark to ground (shock harzard). Might not be a great spark because there is no capacitor in the ground circuit.

I have been using the Pertronix since 2017. I had an issue once where it wouldn't start, early on. I believe the issue ended up being the coil rather than the Pertronix, but I honestly can't remember that far back.


This is the last conversation I had with Pertronix before resolving the issue.


Mine is the Pertronix I


Pertronix Rep:

"Sorry this happened, let's get this issue solved. First off, what Ignitor kit are you using? The I, II, or III? The Ignitor I can be bench tested, so that may be an option for you. Also, sometimes, we lose track of things and mistakes happen. Was the key ever left in the "On" position with the motor "Off"? This can cause damage and/or failure to the module, and may cause issues similar to what you are facing now. I would also double check to make sure you are getting a full 12v to the coil under load (when cranking), check to make sure your grounds for the distributor are clean where it sits in the manifold, and the inside of the distributor is clean where the Ignitor sits in the distributor. Also, if you have any other wires aside from the black Ignitor wire from the Pertronix unit coming off of the negative side of the coil, try removing them, and cranking. This will ensure that nothing is grounding the negative side of the coil. You can also try using a different coil if you have one, just to ensure there are no problems with your current coil."

[James]

I just found this info on the PreTronix ignition unit. Maybe this will help.