Won't run when warm

[Tireguy87]

I've been trying to figure this out on my own but I'm getting frustrated. Here's some background info. 1967 FJ40 with a '75 2f that I just swapped in. Rebuilt Holley carb and I believe a Mallory distributor. This motor ran perfect in the PO's rig. I drove it around before he pulled it. Now that I have it installed in my truck, it will not run when it gets to operating temperature. It will start up fine and idle all day in the driveway but once I take a spin or 2 around the block and get it warm it wants to cut out and has trouble restarting. If I let it sit 3-5 minutes, I can usually limp home in first gear but nothing more than that. The only thing I've changed since swapping it in is the fuel pump because I had a newer one on my old F135. I also swapped over the coil from my old motor because it was newer. But the motor acted the same way with the old coil. Voltage regulator is new and alternator is new. Fuel delivery seems ok as the fuel bowl stays full. I know the overall opinion of Holley carbs is not great around here but I left it on because the PO literally had it rebuilt about 2 weeks before I bought the motor. The battery cables are not getting hot but I did check the coil at idle and it is not putting out a steady 12v. Not sure if that is an issue as I am not an electrical guy. Do Mallory distributors require a hotter coil? The one I removed was not stock but it was leaking a little bit of oil. Thanks for any help

 

[Tireguy87]

Looks like I stumped everyone else too

 

[Pin_Head]

More info please: Define "wants to cut out" and "trouble restarting". What does it do under what circumstances?
Does your Holley have an electric choke? What is different about your installation compared to the PO?

 

[cjgoode]

I am betting fuel pump is not pumping enough or a line is blocked, that might explain why it idles fine and when driving you use up more fuel from the float bowl then is getting replenished. The float in the fuel bowl also might be sticking or clogged reducing the fuel getting into the carb. Moving an engine and installing it can knock crud loose inside the carb or fuel system causing stuff like this. Also check the fuel filter could also be reducing the flow enough to let it idle but not drive.

 

[Tireguy87]

More info please: Define "wants to cut out" and "trouble restarting". What does it do under what circumstances?
Does your Holley have an electric choke? What is different about your installation compared to the PO?

I guess I should have been more clear there. It does die but bucks and sputters before it dies. Then if I try to restart imediately it just cranks. I can pump the gas pedal and get it to sputter but I usually have to let it sit for a few minutes before it will start back up.

The problem usually doesn't start until I get into 3rd gear and pick up speed. Fuel filter is clean and clear.

My Holley doesn't have an electric choke. The only installation difference is that I bought a Holley cable kit from Downey whereas the PO had a hacked up metal bracket and hardware store cable.

 

[miker]

Because parts are ‘new’, it does not mean they are good parts. Anything changed from the old working setup to the current state should be questioned.

I tend to agree with cjgoode on the fuel delivery as highly suspect. Have you checked how much fuel is in the bowl after the engine dies? You should check it before you try to restart or crank the engine. Any cranking of the engine could cause the mechanical pump to replenish the fuel in the bowl and so if you check it after cranking it may be full again.

I've experienced issues with aftermarket fuel pumps for the 2F. Not sure if your 'new' pump is OEM or aftermarket, but at one time, some of the aftermarket ones I was getting were poor quality and I experienced fuel starvation under engine load and as well, vapor lock symptoms when temps were hotter.

I installed a cheap electric pump and put it in line between (and below) the tank and the mechanical pump. Not suggesting this be a permanet solution, but this is what I did to verify the problem on mine. Even after fixing the mechanical pump, I still have it there as an emergency backup. It also works as a priming pump if I have not started the vehicle in a long time.

This is the type I used. They used to be about $20, now they are about $35.
http://www.speedwaymotors.com/Universal-Electric-4-7-PSI-Fuel-Pump,1638.html

 

[Tireguy87]

The fuel pump I put on is OEM. I had it on my F135 with no problems. But I'll put the POs pump back on and try that. I'll also check the bowl after it dies before I try to crank it again. Thanks for the leads. I'll report back.

 

[miker]

Just FYI, there's a plastic or phenolic (sp?) spacer for the fuel pump that I believe some pumps/engines require and some do not. You might do a search on this. Using the spacer when the pump does not require one can cause low fuel flow. Not using one when it IS required may cause pump damage.
Here's one thread on this:
https://forum.ih8mud.com/60-series-wagons/562650-busted-fuel-pumps-rebuilt-2f.html

 

[77 Mike]

When the engine dies is the ignition coil hot?

 

[Tireguy87]

Just FYI, there's a plastic or phenolic (sp?) spacer for the fuel pump that I believe some pumps/engines require and some do not. You might do a search on this. Using the spacer when the pump does not require one can cause low fuel flow. Not using one when it IS required may cause pump damage.
Here's one thread on this:
https://forum.ih8mud.com/60-series-wagons/562650-busted-fuel-pumps-rebuilt-2f.html

I have seen this done but the pump I took off didn't have a spacer and I replaced it with the same pump so I hope I'm alright there.

When the engine dies is the ignition coil hot?

Yes.

 

[pinkiedog64]

Checked for vapor lock? Are the fuel lines/filter located close to the exhaust or block enough to warrant this?

 

[77 Mike]

I had similar symptoms and I think part of my problem was the ignition coil overheating. The geniuses that did the tune-up and replaced the old coil didn't wire in a ballast resistor. Before I fixed it the coil would be scalding hot. Not sure if that's what's going on with your cruiser but I hope this helps.

 

[Pin_Head]

I agree that it sounds like a fuel delivery problem. Check fuel pump outlet while cranking. It should deliver a half cup in 15 seconds of cranking. Make sure that rust/dirt isn't clogging the outlet of the tank.

 

[edwjmcgrath]

My first choice would be fuel delivery too.
Second would be coil overheating because it should have a ballast resistor but doesn't.

 

[Tireguy87]

My first choice would be fuel delivery too.
Second would be coil overheating because it should have a ballast resistor but doesn't.

What the heck is a ballast resistor? Sounds like something from Star Wars

Edit: I just had an epiphany. The PO had something mounted to the firewall on his rig and it had 2 prongs. If I remember correctly, he had one of the wires from the coil running to one prong and then (help me out here if I'm wrong) the other prong had a wire that ran to his starter.

He did not include that part when he pulled the motor so I just wired up the coil like it was on my F135. But it's apparent that something changed in the wiring from '67 to '75

So can I just pick up a ballast resistor at the parts store and wire it in? His was definitely not OEM Toyota.

 

[edwjmcgrath]

There are two different ways to wire coils. With or without the ballast resistor.

If you have a setup without a ballast resistor, it is really simple. Coil positive gets 12v from ignition switch, period. This type of coil is meant to run at full 12v.

If you have a setup WITH a ballast resistor, the 12v from the ignition switch goes to one end of the resistor while the other end goes to the coil positive. This means that the coil runs at around 6v. HOWEVER, when you are cranking the starter, the starter feeds a full 12v to the coil for a hotter spark.

Either works fine, but you can't use a ballast resistor coil without the resistor or vice versa.
If you are running a coil meant to see 6v and you are feeding it 12v, it will overheat and not run right when it's warm.

So you can either get a new ballast resistor and wire it in, or get a coil that will run at full 12v.

 

[Tireguy87]

There are two different ways to wire coils. With or without the ballast resistor.

If you have a setup without a ballast resistor, it is really simple. Coil positive gets 12v from ignition switch, period. This type of coil is meant to run at full 12v.

If you have a setup WITH a ballast resistor, the 12v from the ignition switch goes to one end of the resistor while the other end goes to the coil positive. This means that the coil runs at around 6v. HOWEVER, when you are cranking the starter, the starter feeds a full 12v to the coil for a hotter spark.

Either works fine, but you can't use a ballast resistor coil without the resistor or vice versa.
If you are running a coil meant to see 6v and you are feeding it 12v, it will overheat and not run right when it's warm.

So you can either get a new ballast resistor and wire it in, or get a coil that will run at full 12v.

I know I've got a 12v coil currently installed. Let me ask you this. If I have the coil wired backwards, what would the result be? I'm not saying that I do have mine wired wrong but it's kinda got me thinking. I had this same 12v coil on my F135 with no ballast resistor without problems. Maybe I've fried both of the coils I have?

 

[miker]

In post #1 you said is was a Mallory distributor. If this is a Mallory Unilite distributor then they do require a ballast resistor or resistance wire between 12v and (+) coil.

"Before installing the UNILITE® Distributor, make sure that your vehicle is equipped with an ignition ballast resistor (or loom resistance wire) in the wire between the ignition switch and the coil (+) terminal. Check a service manual for your vehicle to locate the ignition ballast resistor (or loom resistance wire). If your vehicle is not equipped with an ignition ballast resistor, install a Mallory Ignition Ballast Resistor Part No. 700 in the wire between the ignition switch and the coil (+) terminal. Failure to use an ignition ballast resistor will eventually destroy the UNILITE ® Ignition Module."

http://www.summitracing.com/parts/maa-4764101/media/instructions

That being said, I don't think this is the problem you've been describing/experiencing but its would good to review the proper wiring for your distributor type to avoid any future problems and expense.

 

[Tireguy87]

In post #1 you said is was a Mallory distributor. If this is a Mallory Unilite distributor then they do require a ballast resistor or resistance wire between 12v and (+) coil.

"Before installing the UNILITE® Distributor, make sure that your vehicle is equipped with an ignition ballast resistor (or loom resistance wire) in the wire between the ignition switch and the coil (+) terminal. Check a service manual for your vehicle to locate the ignition ballast resistor (or loom resistance wire). If your vehicle is not equipped with an ignition ballast resistor, install a Mallory Ignition Ballast Resistor Part No. 700 in the wire between the ignition switch and the coil (+) terminal. Failure to use an ignition ballast resistor will eventually destroy the UNILITE ® Ignition Module."

http://www.summitracing.com/parts/maa-4764101/media/instructions

That being said, I don't think this is the problem you've been describing/experiencing but its would good to review the proper wiring for your distributor type to avoid any future problems and expense.

I'm not sure that's the model I have as mine doesn't have a vacuum advance. I searched around on the Mallory website and I couldn't really find one built for a 40. I'll check the distributor itself and see if maybe it's got a number on it.

 

[Pin_Head]

I doubt that it is a coil problem. They just tend to burn out and stop working rather than being an intermittent problem.