The Stovebolt Site Forums The Shop Area The Electrical Bay Hard starts *UPDATE* #2

In my never ending quest to figure out the culprit of my random hard starts, I'm hoping I discovered something today.
This morning I was troubleshooting the overcharging problem I was having. It turned out to be the alternator I purchased a couple months ago. I finished my final checks, buttoned things up and shut the motor off. Came out 1/2 hour later to go to work and she just cranked. It had fired up several times earlier with no problem.
This has happened randomly for the last couple months whether engine was warm or not. The kicker is, it will start if I jumper the starter with a screwdriver.
I decided the next time this happened, I would read voltage at the power wire at coil and at the "S" terminal on starter with engine cranking. I had 12.1 volts at coil and only 9.9 at the purple ignition wire at starter.
Am I on to something here? Should there be 12+ volts at the "S" terminal?
By the way, I've switched over to HEI last May and didn't have any start problems until a couple months ago.
-David

This has me confused as well. As long as you have 12 volts at the coil while turning over, it should fire. The 9 volts at the S terminal might be due to the voltage drop from the silinoid working, seems normal(while turning over). If you have 12 volts at the coil while turning over and it still not starting, must have a problem with the distributor.

Probably the module or pickup coil. Try the module first it is real easy to replace. If you had a high charging voltage it could have fried the module. I like to replace them both & clean up the dist. & lube the advance mechanisms. Its no fun getting stranded out there.

The power wire to coil is wired to my fuse box. There was an avaiable terminal so I used it when converting to HEI. Maybe that's why there's a definite 12V there?
So it's no big deal there's only 9.9V at purple ignition wire at starter?
I'm trying to understand why it'll start when jumpering with screwdriver. What's different when I do this? What changes when the positive battery terminal and S terminal are momentarily connected with screwdriver? Is the job of that ignition wire to complete the circuit when key is turned to crank engine?
I did order another distributor as mine's still under warranty. But, the guesswork is killing me. I keep thinking it's gotta be wiring 'cause it'll always start with screwdriver. Oh yeah, if anyone's thinking solenoid, my old starter crapped out 2 weeks ago and this hard start thing continues to happen with new starter/solenoid.
-David

Check your grounds.

Verify the wire at the fusebox doesn't go dead while cranking (like wipers, radio do). Maybe connected to wrong circuit? Connect to ign switch where original resistor wire originates from. Should do it!!

Checked grounds today. Everything seems good.

The power wire from fuse box to coil gets 12+ volts when engine is cranking. If that terminal went dead when key is cranked, it wouldn't be a random thing.

It's the 9.9v and the screwdriver that confounds me.

Hi Mugsy. I suspect your ignition switch.

When the switch is in the "run" position, it seems to work fine. Power is provided to the ignition and the truck runs.

When the switch is in the "start" position, the engine cranks OK, but I suspect that it disconnects the power to the ignition on those times that it won't start.

Your screwdriver trick bypasses the flakey "start" position which means that the switch provides power to the ignition while cranking and the engine starts.

You have a voltmeter. Next time it doesn't start connect the voltmeter to the ignition terminal on the switch and observe what happens while cranking. If the power cuts out, you know the switch is toast.

Gord, that's a good theory however, I changed the ignition switch a couple weeks ago when I cleaned up the engine harness wiring and firewall plug.
Two weeks ago when I really started digging to find the problem, I found the purple ignition wire kinked and with a couple bare spots down by the "S" terminal. The wire was long enough to cut the bad area and splice new connector for solenoid. Inspected wire up to firewall plug. Cab wiring to ignition switch looks factory and unmolested. Then I checked the firewall plug and it was corroded. I cleaned both sides of plug. I thought for sure this would cure my hard starts. At this time I also changed the ignition switch just to be sure and also because a couple months prior I was driving and everything cut out. My lights started to go dim and then engine petered out. I pulled over and looked under the hood. All was normal. Tried to start and she fired right up like there was nothing wrong. My random hard starts were happening prior to this incident.

If I remember right, the purple wire is only for starting. It supplies power to pull in the solenoid of the starter. It has nothing to do with the distributor. The key switch sends power out by way of the purple wire only in start position. The "R" terminal on the solenoid is to supply power to the coil when in the start position. If this wire is not connected, it won't start, UNLESS you have the coil wired direct from the fuse box or some other sorce. With HEI its best to hook the feed wire directly to START and RUN at the key switch and run a single 12 gauge wire to the distributor. Just jumper across RUN to START and see what happens.

My guess is when you screw driver start it you are back feeding 12 volts up to the key or fuse panel. Thats the only thing that can be happening if you do not have the "R" terminal hooked up. This second wire "R", was GM's way of getting full 12 volts to the coil in the start mode. Once started the resistor wire from the RUN circuit knocked the voltage down to 9 or 10 to keep from burning out the points. They found it was to hard to get them to start with lowered voltage.

For the random acts of not starting, could be a weak moduale in the HEI and its acting apon the voltage variances when starting. You could still have a questionable connector someplace.

If you are running the HEI through the bulk head connector, you may want to rethink that and hollow out one of the holes to feed a direct wire out. HEI likes full power, the more the better, and each connection you have will reduce that voltage down.

Joe

Joe H, you are correct. The purple ignition wire runs from S terminal to ignition switch.
The power wire I ran to coil is directly routed to coil and is getting 12+ volts. I brought this up previously to show I had 12v there.
What makes sense to me, is the truck will start with screwdriver 'cause I'm applying direct battery juice to the S terminal. There's no doubt about that voltage. When cranking the other day, I had 9.9 at S terminal. Apply a little more juice, in this case with a screwdriver and it starts.
I ordered a new engine harness last night. Maybe some of that corrosion crept up the wiring and is causing voltage drop. Perhaps just cleaning the plug and repairing wiring was not enough in this case.
-David

Just had a thought. What if while I'm waiting for the new harness to arrive, I run a new wire from ignition switch to S terminal and check voltage? If voltage increases, I know that was problem. If it doesn't increase, I go get a sledge hammer and beat something to a pulp!

If the starter solenoid wire is/was cracked and corroded, it makes sense that the other wires in the harness are not in good shape. Hopefully, your new harness will be the cure.

David, you need to look at a wire diagram to figure out where the power is going when you back feed the system with a screw driver. If you are getting 12 volts at the coil, why does extra make it start? This is very interesting problem, at least from this side anyway :p . From your view its just a pain.. Keep us posted, Joe

Two more hard starts in the last weeek. One Saturday morning, engine was hot. One Monday night, engine was cold. Each time a screwdriver on the starter got her to start.
OK, I'm trying one last thing before swapping the distributor.
I noticed on the '64 that I recently bought, it had a remote starter solenoid. Presumably for hot starts as it's a 283. Doing some research on my problem I found this page: adding remote solenoid
I took the one off the '64 and installed on the '65 wiring it up just like the diagram shows. I checked voltage and now I have 10.9 instead of 9.9 at "S" terminal. Don't know if 1 extra volt will help or not.
Joe, looking at the wiring diagram, the purple wire runs from S terminal to ignition switch. When key is turned to crank engine, I have 10.9V at ignition switch on purple wire terminal. The red power wire at ignition switch is 12.1V. Does the red power wire at ignition switch feed power to purple wire and then down to starter? Or vice-versa, turning the key allows power from bat. terminal thru solenoid and up the purple wire towards ignition switch?
What I did kinda seems like a weird fix, if it does fix the problem but, I just don't know what else to do.
-David

Well it sure didn't take long to learn the remote solenoid wasn't the cure. Did the crank only thing again, and again, screwdriver got her started.

I just don't friggin' get it!

Just for sh!ts and grins, is there anyone out there with a '63-'66 that'd be willing to read out voltage at "S" terminal purple wire while engine is cranking, so I have something to compare to?
I've got another distributor to put in but, I just don't see the correlation. Intermittant ignition module or pick-up coil but, jumpering the starter with screwdriver makes it start?

I just don't friggin' get it!

I'm about ready to give up and take it to an electrical shop. And that just ain't right!
-David

Joe H Joe H Fran and Gord You have been getting some good advise here and I don't hear you checking these things out.
You need three things to start an engine.

• Fuel in the carb.
• Spark at the appropriate time.
• A way to turn the engine over.

My best quess is that you have two of those items. Which one do you think that leaves you to check out?

You wrote Pull one of the spark plug wires off. Put another spark plug in the wire end. Ground the body of the spark plug on the engine someplace that has no paint. Crank engine and see if the plug is firing. If not, jack the radiator cap up in the air and put another truck underneath it.
You have been told a number of times to check the grounds.
Your reply was For some reason I'm not very confident with that reply. It requires the use of a voltmeter and not the one that you know to be questionable.

Richard,
I have checked "these things out". As far as ignition switch, the problem occurred with old switch and is still happening with new switch I installed a month or so ago. As far as the wiring goes and looking at wiring diagrams, I asked some questions in the last few posts that no one has answered. Not even you, Mr. Smartypants. :p
I did check grounds and then rechecked grounds and then rechecked grounds again. I used the multimeter I own (which began to read correctly after changing battery) and then checked things again with the nice, expensive Fluke multimeter we have at work.
I have checked for spark on several occasions now. There is spark.

The direct battery voltage being applied to "S" terminal with screwdriver makes it start when the problem occurs. If it's backfeeding, where is it going? The purple wire runs to ignition switch. Is it most likely that added voltage is being backfed thru purple wire, up to ignition switch where it then transfers to 12ga red power wire which in turn runs to fusebox?
How the heck do I even check this? Have someone hold a screwdriver on the starter while I run around checking voltage?
And by the way Richard, I'm sure it's not your intention but, your posts come across as quite condescending. Maybe it's just me, how I'm reading it. Anyways, I do appreciate the help/advice. Just wanted to mention that in case you were not aware.
-David

Don't trouble shoot the screwdriver condition. Trouble shoot the condition where you turn the ignition key.
Does the engine turn over noticeably slower with the key than with the screw driver?

To answer your question. I had to disconnect the dist to get a solenoid reading because it starts up too fast. Ground on engine, solenoid read 9.8 volts. Lower than I expected, but has never been a problem and never had reason to check.
If you are getting a spark and fuel and it cranks, then there is something about the info and the conditions that you are giving us that is either inaccurate or somehow not in sequence that allows us to see the picture.
For instance. You say when you crank the engine over with the key, you are getting 12 volts at the distributor and a spare plug on one of the wires is sparking, yet the engine does not start. You now get out of the truck leaving the key in the run position and with a screw driver it then starts. You've given no indication that it was starving for fuel earlier and now fuel has been pumped into the carb. You have not indicated that the engine cranks faster with the screw driver than with the key. If the plugs had been fouled, they did not clean up instantly. Is the voltage at the distributor now greater than it was before? Are you now getting 12.5 or maybe 13 volts at the distributor?(from a 12v bat delivering 250 amps to the starter) Is the spare plug (what) still firing?
Condescending or not, 12volts at the coil and no start when cranking with the key doesn't work for me. It's either bad meter, bad ground or bad information gathering.
When you do start the engine what is the volt reading at the dist??

Richard
Screwdriver, yes. Fuel not an issue. Most of the time, the truck fires up in a split second. It'll sit all night, I jump in and she fires right up without even giving her gas. A couple months ago when this first started happening, I checked the basics first like fuel and spark.

The motor starts very quickly when jumpering the starter. Doesn't seem faster, seems the same but, hard to tell as it starts up so fast.

Do you mean after the engine has started and is running? If yes, I have 14.42 using Fluke multimeter we have at work and 14.4 using my own.

I am really curious what the readings would be with the starter jumpered out. Suppose I jumper the starter with a push-button switch or something. Turn the key and have someone push the switch while I read out? See if that voltage is being backfed and where it's going?

quote:
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Are you now getting 12.5 or maybe 13 volts at the distributor?(from a 12v bat delivering 250 amps to the starter)
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No, that was tongue-in-cheek. It's hard to to get 13 volts out of a 12v battery while it's turning the motor over and the alt hasn't started to charge yet. What I am asking is
quote:
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For instance. You say when you crank the engine over with the key, you are getting 12 volts at the distributor and a spare plug on one of the wires is sparking, yet the engine does not start. You now get out of the truck leaving the key in the run position and with a screw driver it then starts. You've given no indication that it was starving for fuel earlier and now fuel has been pumped into the carb.
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The question is not about when it starts with the key or about when you stick a screw driver in it.
The question is, what is the voltage at the dist in the no start condition when you turn the key to start.

The voltage is 12.1 volts when engine is cranking.
9.9 volts at S terminal (now 10.9 with remote solenoid) and 12.1 at coil and dizzy.

In this same engine, "unable to start" condition. You had 12.1v at dist with key in "start" position. With key in "run" position, what was the voltage at the dist? Where did you have the volt meter ground wire connected? Not asking about the voltage readings if you could start it with the key.

Recently, when it "acted up" and wouldn't start with key, I grabbed multimeter, had my wife turn key and I read out 12.1 volts. I read at S terminal also which at that time was 9.9. Jumpered the starter so I could drive to work. Then later at work, when it would start with key, read it out again and had 12.1 volts. I used battery ground cable at engine block for a ground and also the ground at the coil.

Hope we can help you figure this out soon. Maybe next time it acts up unhook the wire to the coil and the starter. Hook the meter to the coil power supply. Turn the key to start and see what you have for voltage. Make sure the starter wire is not touching anything. Then take a jumper wire and supply power to the small starter wire (key in the run position) and see if there is a difference. How is your distributor wired up? Can you tell if it is wired directly to the key switch?

You said that when the engine is running, you have 14.4v at the dist. That's fine. The problem is that under every other condition you say there is 12.1 volts there. Key in run position, 12.1v. Key in start position, but unable to start, 12.1v. Always 12.1v. When the starter is cranking, the voltage should be lower. :confused:
Big T may have hit on the solution. I have a feeling that if you pull the wire off the coil, there will be no voltage there in the "start" position. Only in the "run" position.
If I remember correctly, you have the external coil? The Bat wire is to the right of the High voltage post and the tach wire is to the left as you look at it from the top?

Mugsy,
Does your truck have an amp gauge? There is a resistor in the circuit to the "R" terminal. Bad resistor?? If not, there should be two wires going to the "R" terminal. One is white/orange/purple coming from the bulkhead connector. The other is yellow going to the coil from the "R" terminal. There should be a single purple wire on the "S" terminal, this is your crank signal wire(hot in crank). Look for the pink wire at the ignition switch connector (changes to the w/o/ppl at the bulkhead connector). This should be your "run" voltage. If you're running HEI, you should have 12v from the "run" circuit to the "R" terminal. Do you have two wires at the "R" terminal? You can try running a redundant wire for the "run" circuit from the switch to the "R" terminal and see if this eliminates your concern.
HEI should have 12v at the "R" terminal, translating into 12v from the yellow (coil)wire coming out from the "R" terminal. Make sense??
Hope this helps.

Jim Sgrig

I believe you are correct. I think he originally had two wires on that post but removed them when he put the HEI in. One wire to the coil. One resister wire to the ign. switch. His new pickup location was to supply voltage for "run" and "start". I think he may not getting it in the "start" part of the time or maybe not even at all. I think the 12v reading he is getting may actually be coming from the tach connection.

Or, you could just bypass the "R" or "run" terminal from the starter and just run a wire from the "run" voltage terminal of the switch (pink wire) directly to the coil. With HEI, there is no need for "reduced voltage" at the coil B+ terminal. But, you will need to make sure you have 12v at the pink wire at the ignition switch first.If not, you probably have a defective switch. It wouldn't be the first time I saw a "new" component be defective.

JS

No, I wired the power wire to coil a straight shot with 12 ga. wire from a spade terminal on my fuse box labeled "ignition unfused". There are two of these spade terminals. When key is turned to first position (is that run or start?), I have 12.3 volts at fuse box and at coil. With power wire at coil disconnected and key turned so engine cranks, there is 12.1 volts at coil power wire. I do have 12+ volts at pink wire at ignition switch but chose the fuse box terminal instead.
Today, I tried BigT's suggestion. Wasn't "acting up" but, was curious to see what would happen.
Disconnected power wire at coil. Disconnected purple wire at S terminal. With key in first position, 12.3 at coil power wire. With key engaged to start engine but, no starter load and engine not cranking 'cause purple wire disconnected, voltage increased to 12.6 volts. I had the same reading at purple wire which surprised me. Guess that's because it wasn't hooked up to S terminal and there was no current draw. When the purple wire is hooked up and starter engages and motor cranks, there's 9.9 volts at S terminal and 12.1 at coil power wire.
I'm going to try the same thing again but, leave the S terminal hooked to the starter and disconnect coil power wire. I'll then use a spring loaded toggle switch (conveniently borrowed from work) and jumper the starter with toggle switch (this is now my screwdriver). Turn the key to first position, engage toggle switch and get reading at coil power wire.
The one time I read voltage when IT WAS acting up, I had 12.1 volts at coil power wire with motor cranking. And 9.9 volts at S terminal. Then I jumpered the starter with screwdriver and drove to work.

Piewagon, I eliminated the wiring going to R terminal.
-David

Make it simple, find another power source and try that.

Just make sure the power supply has power when the key is in the run position and in the start position and no power in the off position. And make the voltage is the same at both run and start.

OK, the rain stopped long enough to perform test. Hooked up wiring to configuration before remote solenoid (installed a week or so ago for troubleshooting): Purple ignition wire to "S" terminal on starter, positive battery cable direct to post on starter, coil power wire direct from "IGN. UNFUSED" terminal at fusebox out to coil.
Here are the readings I had.
-With NO JUMPER on starter:
-Key in off and 1st position = 0 volts
-Key in 2nd position (gauges work)= 12.3 volts read at coil.
-Key engaged fully, engine turning = 10.4 volts read at coil.

-With starter JUMPERED (using spring loaded toggle switch between pos. post and "S" terminal on starter:
-Key in off and 1st position = o volts
-Key in 2nd position (gauges work)= 12.3 volts read at coil.
-Key engaged fully, engine turning = 10.9 volts read at coil, read at fusebox, and read at pink wire at ignition switch (just to compare with fusebox terminal).

So, the difference with a jumper is an increase of .5 volts. After my little test, I reconnected everything and attempted to start truck. She fired up.
So what does all this mean? I DON'T KNOW!!!!
The .5 extra is making a faulty ignition module or pick-up coil work?

The HEI should start with 9 or 10 volts, they like full voltage but still should start when low. Your voltage at the purple wire shouldn't have any effect on how it starts. All this wire and voltage is doing is pulling in the starter solenoid. It has nothing to do with the HEI or ignition switch. You proved that with the remote solenoid.

Before changing a lot of stuff again, try this when it won't start. Hook a wire from battery (+) to the HEI coil, then use the key switch to crank it. Do nothing else!

It better start if it cranks, if not, pull the modual, trash it, and get a GM unit!

Again, go from battery post to coil only!

Just for kicks, once running, pull and tug on the wires fron the coil to the modual. Also get the vacumm advance to pull in and out to check its movement. Each time it moves, so do the small wires inside. You might have a weak wire at or in the HEI itself.

Another thought, when it acts up again, don't do anything to it other than hooking up a battery charger with Booster/start mode if you have one. By adding more power all around it should start.

I don't know what this will tell us other than it needs more voltage, which may lead back to the modual being weak or bad.

Joe

I would try another HEI. Just this weekend I had one die, which had aftermarket components inside. I drove this truck, parked it with no signs of failure. Came out in the morning to drive it to work, no start. I put an all original HEI out of another engine I have and she fired right up and runs better now than it ever has. I always recommend using Delco ignition parts when fixing the HEI stuff.
Scott

I hope I'm not jinxing myself but, I think this problem is fixed. I swapped out the distributor last Saturday as all the troubleshooting led back to possible intermittant ignition module or pick-up coil. Been starting no problem for a week now. Thanks everyone for the input/advice.
-David