Scout II Doesn't Always Start!

S

ScoutII22

Member
Hi everyone, just wanna say thank you in advance to any help I receive.

Okay, first off.
1979 Scout II
345v8
727at
Holley 2300 2barrel 500cfm
superstock coil
prestolite electronic distributer

this is my first vehicle I have ever owned, I'm 17 years old, so any help is greatly appreciated. I know the basics but I'm still learning.

Okay, so, this Scout has been a pain in the butt. I bought it with a fresh rebuild on the engine but not ran in 16 years. Picked it up for a great price in great condition. I did the common tune up including:
spark plugs
new carbeurator
oil change
radiator water change
swapped old coil with a superstock coil.

For starters, when I go out to start it, it usually always starts, but it usually only runs for about 10 minutes, then it shuts right off, and wont start after that. I have noticed the coil gets very hot, and I do have a ballast resistor inline. I have taken several electrical readings.
Just now, I started it up it ran for a while, then shut off due to lack of fuel. Just to do it, I checked voltage to the coil. The + side was getting 7.5 and the - side was getting 2.5. Then I started it back up, it ran and then suddenly shut off. I checked the voltage again, + was getting 12.5 and the - was getting 12.5. I tried to start it again and it wouldn't and still wont start back up. It's been about 30 minutes so I'm gonna go check it right now. Checked it just now, same old, + 12.5, - 12.5. I just bought a msd 6a box, to try to solve the problem, but I cant seem to find the correct installation instructions. Can any one help me out? I really love this Scout and I've always wanted a project but I just cant seem to catch a break with this thing. Help!
 
Welcome young man! Let's see if we can't get you squared away on some things. Firstly, with the presto no points igntion, you do not need a ballasted feed to the coil. This also means that you do not need a resistor bypass feed from the solenoid 'r' terminal up to the coil + terminal. So, you should be feeding full b+ to the coil + terminal from an 'I' terminal of the ignition switch both during starter crank and when the key is switched to on position. Remove the ballast from the equation as that is only for breaker points and certain points eliminating modules...it does not jive with the presto.

Now, as to your carb choice, I'm going to lay some tough lovin' on you by saying that the list 4412 500 cfm version of the Holley 2300 is really not appropriate for any IH sv8 engine in stock form. It is calibrated way too fat across the board for the needs of our slow revving, asthmatic breathing prime movers. The problem isn't just the jets, or this one component or that one component. Its basically the whole shittery. I know this isn't what you want to hear. I know you spent some cabbage on the thing, but if only you could have dropped by sooner before the purchase, we would have steered you towards the list 0-7448 which is the 350 cfm version and is a very popular choice. That said, the first thing you need to concern yourself with right now is making sure your ignition and electrical systems are completely squared away. That way the thing will at least start up and run...maybe not all that great, but at least it will run. Then we can help you figure out which direction you want to head with the mixer.
 
This is the correct distributor, right? Okay, so first thing I do is remove the ballast resistor, because the reason I put the resistor in, is because the coil was getting very hot before, as it is now.
 

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Yes, a prestolite distributor is correct for a '79 model year. I hope you still have the original coil. There was probably nothing wrong with it. I'm not a fan of many of the aftermarket coils for use in stock applications. Generally, they amount to a bunch of marketing smoke blow in a can with fancy lighting bolt graphics on the outside. Unless you have a capacitive discharge setup in play, there is really little if anything to be gained with a coil that "claims" to be capable of outputting elevendybillion volts. Your ignition system at present can't really make use of any more juice than a stock coil is capable of producing anyway. The other variable that we don't know about is the internal resistance of your super coil. By comparison, we know that a stock coil has roughly 1.5 ohms resistance, which is ideal for the prestolite setup. Your new coil would need to be measured with a digital volt meter set to measure resistance in ohms on the lowest setting to determine its value.
 
So how exactly do I check ohms on a coil? Negative terminal to black and positive terminal to red? And what exactly is a ballast resistor bypass? Sorry for my lack of expirience with all this. Thank you so much for your help. And what is the best way to get at that ignition switch and check that? Its very cramped and not exactly spacey down there. I'll try to post more pictures of my set up tomorrow. Thank you!
 
And the other thing, is that when I cant start it back up, its because of a lack of spark. There is absolutely no spark anywhere. I have checked multiple spark wires.
 
scoutii22 said:
so how exactly do I check ohms on a coil? Negative terminal to black and positive terminal to red? And what exactly is a ballast resistor bypass? Sorry for my lack of expirience with all this. Thank you so much for your help. And what is the best way to get at that ignition switch and check that? Its very cramped and not exactly spacey down there. I'll try to post more pictures of my set up tomorrow. Thank you!
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If you have a digital voltmeter with an ohms setting, it will have an icon that looks similar to old-school stereo headphones. Put it on the lowest readout possible. Then disconnect any wires hooked to the coil + and - terminals. Label them if you feel the need. Then probe across the terminals, red to + and black to -. Actually, in this case the color coding doesn't matter, but its a good habit to get in. You should see a small number like 1.5, 1.0, 0.5...those are just examples. Post your finding.
For now, let's assume that your ignition switch wiring is okay and concentrate on the engine side of the firewall. I think we will find plenty of things to tidy up there, and we May not even need to go behind the dash. How's that for wishful thinking?:cornut:
the resistor bypass is simply a wire that runs from the 'r' terminal of the starter solenoid up to the coil + terminal. You actually shouldn't have this wire anyway, as it is only used on older models with breaker points ignition, but I want you to double check it anyway. If you see any wire connected to the solenoid 'r' terminal, it can be disconnected at both ends and removed. The sole purpose of this wire is to bypass the resisted or ballasted power feed to the coil and provide full battery power only during starter cranking. Once again, this is not applicable in your situation. The power feed running from your ignition switch to the coil should be providing 12.x volts both during starter crank and while the key is switched on.

scoutii22 said:
and the other thing, is that when I cant start it back up, its because of a lack of spark. There is absolutely no spark anywhere. I have checked multiple spark wires.
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We'll get to that. Clean up your power feed to the coil as previously stated. Make sure that your battery is in good condition and fully charged. Double check battery terminals/cables for cleanliness and tightness. Take a close look at the terminations on the starter solenoid. Is everything tight and free of corrosion down there?
 
When I ohm the coil on the lowest setting, I get 1.6. It's a brand new starter solenoid, but there is a yellow wire running from it into a solenoid looking thing, and then into the ?bulkhead connnector? I think is what its called, ill post a picture of it.
 

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1.6 at the coil is fine. How many wires are connected to the coil + terminal? Have you removed the ballast resistor from the equation? The item in your pic is a Ford remote starter relay. It is not an original part, but it is a very common modification.
 
Am I right in saying that the thing to the right is a bulkhead connector? I did remove the ballast resistor. Is the Ford remote start relay nessesary? Why is it there and what does it do? I have total of 4 wires to the coil. 3 to the positive, and 1 to the negative. The 3 to the coil + consist of 1 red from the distributer, 1 black coming from underneath the coil (which receives 12v) and 1 black from a condenser? On top of the coil. The 1 one on the - side is a brownish one from the ditributor
 
Yes you are correct. Good! It is not entirely necessary, but it is a worthwhile modification to have. The problem I see with yours, is that whoever installed it did not wire it properly. Your battery + cable should connect directly to one large terminal. Then another battery cable chunk should run from the other large terminal down to the large terminal on your starter solenoid. Then you need to have a short jumper wire running between the 's' terminal and large terminal of your starter solenoid. This curious wiring is most likely to blame for most if not all your inconsistent starting. Once fixed, I bet you have far better results.
 
But would this be the solvent for the fact that when it is running, it runs fine then shuts right off, and will not start back up?
 
Suffice it to say for now, that it is an identified problem which needs to be addressed. Whether or not it winds up curing all your ills is yet to be determined. I'd like to see a pic of the wiring terminations down at your solenoid. We've got some work to do between there and the remote relay.
 
Before starting, with the key in the on position, how many volts should the coil be receiving? And while running? Like I said it gets 7.5+, and 2.5-, when it starts. And when it wont start it gets, 12.5 and 12.5.
 
Sorry for the contiuous posting, but when I had an old, terrible battery, it would run for only 10 minutes, but as soon I put a brand new battery on it, it ran for about an hour.
 
Those numbers were with the ballast resistor in play, yes? If so, they amount to dirty bathwater and should be discarded. Really, I don't see much point in taking voltage measurements until the obvious wiring issues have been addressed, as doing so will likely affect the outcome. But for information sake, the coil should be getting 12.x any time voltage is being transmitted to it from the ig switch. That is during starter crank, key on engine off, and engine running. It should be 0 volts engine off key off or in acc position. Avoid leaving the key on without the engine running except for conducting quick voltage measurements. Energizing the coil and pickup module inside the distributor for more than a few brief moments with the engine stopped is bad juju.
 
You don't need to probe the coil - terminal. We're only concerned with the + power feed. That figure indicates a voltage drop. The battery supply is probably depleted and needs to be restored to a full surface charge of @ 12.8 volts. Take a reading across your battery terminals. What do you get?
 
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