I've been chasing a hot start problem that I just can't find.
The engine starts fine cold. Runs fine.
In trying to restart it warmed up, it's being difficult.
I've isolated this down to the coil firing at something like 25% of what it should or what it fires at cold.
Also the tach won't rev over 1,200 rpm.
What's been done so far, cleaned all grounds and checked for resistence. New ignition switch. New ignition coil (the third one). Switched to yellow top with new resistance wire to ignition. Took out Petronix and went back to ignition points.
Coil phenolicly isolated from engine heat.
Again, this is the ignition not firing hot. Carbs are not involved in this. This won't even fire hot with starting fluid.
...and yes Coralsnake, pump gas with ethanol (corn juice) in it. ::)
In 50 years of running these cars, I can't say as I've ever encountered anything exactly like this and stated plainly, I'm stumped.
I'm open to CONSTRUCTIVE ideas. Nothing like, well push it off a cliff or gt a Corvette please? :o
Does the tach read properly when cold? Could try bypassing it to see if it fixes the hot start problem.
Quote from: 67350#1242 on September 23, 2020, 11:30:32 AM
Does the tach read properly when cold? Could try bypassing it to see if it fixes the hot start problem.
No it doesn't.
Something out of the ordinary is going on here. I was wondering what the tach might have on this and also the starter solinoid. Both are in the ignition circuit.
I had the same issue recently. Once heated up the car would not start. Changed coil and all good for the moment! Have not really tried a long cruise then tried restarting but on a short one she starts right up after shutting off. That was the problem before the issue so I went with an older coil that I knew was in good shape.
Steve
Quote from: kingchief on September 23, 2020, 01:42:06 PM
I had the same issue recently. Once heated up the car would not start. Changed coil and all good for the moment! Have not really tried a long cruise then tried restarting but on a short one she starts right up after shutting off. That was the problem before the issue so I went with an older coil that I knew was in good shape.
Steve
I agree, that if someone asked me what I thought the issue most likely could be, I'd say that it sounds like an intermittent coil.
I followed my own advice. I had a Petronix "flame thrower" in the car. Replaced it with a new one. Same issue.
Then I replaced it with a reproduction "yellow top". Same issue. Fires right up cold. Not so much hot.
Now to me, all the three coils test "good" and what are the odds that all three are no good? Very, very low?
To answer 67350#1242's question, it makes no difference. I just tried the switch to verify this and nada.
The only thing left in the system is the starter solenoid. I'mwondering if somehow the internal contacts are carbonized? It takes more power to start a hot engine then a cold one. I suppose that is worthy of a try as well?
I know that I am right on an ancient Mohegan hunting trail. That's documented. I'm wondering if I've pissed off the ghost of the medicine man and I need to make some sort of offering to make things right? I often have bizarre electronic haywire malfunctions.
Anyone know anything about that? John Barnes was always swearing about that. Where he was from, you couldn't stick a shovel in the ground and not find bones from a "French and Indian War" gravesight?
Maybe this is like the "south seas anomaly"?
More likely the starter is junk. Or a bad battery. Either of those are under a much more severe load when hot and the voltage drop in that circuit directly affects coil voltage while starting.
I would start by having the battery load tested. Free at any auto part store.
If that's not it then make sure all the cables are good. If they are then have the starter load tested. Free at any auto part store.
shelbydoug,
Does the car turn over if it does no problem with the solenoid? Are you getting 12 volts to the coil at start up? Should have 12 and then 6 when running. I had the same problem that kingchief talked about 15 years ago and replaced an aftermarket coil with my original ford yellow top coil no problems since. Weird that your tach does not work. I have been running a Petronix set up for 25 years no problem. Good luck
Bryan
Quote from: BDT 739 on September 23, 2020, 07:54:24 PM
shelbydoug,
Does the car turn over if it does no problem with the solenoid? Are you getting 12 volts to the coil at start up? Should have 12 and then 6 when running. I had the same problem that kingchief talked about 15 years ago and replaced an aftermarket coil with my original ford yellow top coil no problems since. Weird that your tach does not work. I have been running a Petronix set up for 25 years no problem. Good luck
Bryan
My son is always criticizing me for too many parameters going at the same time.
I think that Royce MAY have hit on the significant factor?
One of those, "too many parameters"...I replaced the cable to the starter with a "correct" 4 gauge and the same to the battery negative.
I probably don't need 00 (some call it 2/0) gauge but tomorrow I am changing them out. This is a recent issue and so is changing out those cables.
I've "smoked" the solinoid a couple of times trying to start this thing hot. Where there's smoke, there's fire.
I'll bet Royce drinks Jim Beam? If this works, I'll need an address for that shipment.
The tach is a separate issue. I think I'm gonna' need another one? It didn't like the Petronix I guess?
My KR would go through starters like crazy i swear every couple of years i would have to replace it , i think the heat soak from a big block would just cook them.
Quote from: 68krrrr on September 23, 2020, 11:42:03 PM
My KR would go through starters like crazy i swear every couple of years i would have to replace it , i think the heat soak from a big block would just cook them.
I would agree with this if you are speaking of the Ford starter.
I went with a Tilton race starter. They are MUCH heartier.
I bought a Tuff Stuff starter for my shelby through NPD several years ago. Works great. 100% new, Made in USA in Ohio.
Link below:
https://www.tuffstuffperformance.com/i-24485973-oem-style-starter-full-size-2-bolt-mounting-black-3124b.html?ref=category:1267354
I thought this was a spark issue, not a cranking issue?
Quote from: KR Convertible on September 24, 2020, 10:07:02 AM
I thought this was a spark issue, not a cranking issue?
+1. I don't believe a starters draw would drag down spark performance.
Quote from: Royce Peterson on September 23, 2020, 05:19:35 PM
....................... severe load when hot and the voltage drop in that circuit directly affects coil voltage while starting (cranking).
This IS a real possibility, as we have witnessed this in particularly rear mounted battery relocation installations repeatedly over the decades. ;)
Scott.
Quote from: pbf777 on September 24, 2020, 02:06:18 PM
Quote from: Royce Peterson on September 23, 2020, 05:19:35 PM
....................... severe load when hot and the voltage drop in that circuit directly affects coil voltage while starting (cranking).
This IS a real possibility, as we have witnessed this in particularly rear mounted battery relocation installations repeatedly over the decades. ;)
Scott.
We're going to find out by changing the battery cable size. If nothing else, this is educational but as stated by me, two wires were changed out by me (to 4 gauge). I doubt that it is coincidental?
2/0 (00) cable takes a day or two to get here. Nothing local. So nothing happening today with that.
Should we have a para-mutual event here? Who wants to lay a wager and who wants to give odds? Anyone?
I think that I can change this to a survey? Bet it's the cables/bet it's something else?
To add interest to the wager thing, I will say the wires do get HOT and the solenoid can wind up smoking. :o
If he cant rev over 1200 rpm I would say the power valve in the carb is blown.
ok I read that its not a carb issue, hmmmm there is not so much in the ignition system, so it should be a voltage problem, maybe your battery shows 12 V but the cells are broken so it dont has the capacity anymore that your car will need. Change the battery before you change anything. Redtop should work 100%
Quote from: Kent on September 24, 2020, 02:42:54 PM
If he cant rev over 1200 rpm I would say the power valve in the carb is blown.
ok I read that its not a carb issue, hmmmm there is not so much in the ignition system, so it should be a voltage problem, maybe your battery shows 12 V but the cells are broken so it dont has the capacity anymore that your car will need. Change the battery before you change anything. Redtop should work 100%
Nothing has been said about a dragging starter symptom. If the battery has enough voltage to crank the engine then it should be more than enough to supply the ignition system. The ignition system does not draw much.
Quote from: Kent on September 24, 2020, 02:42:54 PM
If he cant rev over 1200 rpm I would say the power valve in the carb is blown.
ok I read that its not a carb issue, hmmmm there is not so much in the ignition system, so it should be a voltage problem, maybe your battery shows 12 V but the cells are broken so it dont has the capacity anymore that your car will need. Change the battery before you change anything. Redtop should work 100%
The TACH won't indicate over 1200rpm. The engine at cold start up is 1700rpm. Second new battery.
No one wants to wager hey? :o
My bet is the starter. Maybe you should sacrifice some fire water for the Mohegans?
Quote from: kjspeed on September 24, 2020, 07:10:49 PM
My bet is the starter. Maybe you should sacrifice some fire water for the Mohegans?
I'm willing but where do I leave it and are there chicken bones involved?
I have experience with alcohol and howling at the moon in Native American type surroundings but that did nothing but get the local police involved. It's definitely not the way to go.
Maybe I missed it...have you tried a new solenoid? In my experience they can do freaky things like coils. Had a weird thing a few years ago where my 66 just kept running when the key was turned off. At first I was convinced it was the ignition switch. Nope, it was the solenoid.
Quote from: s2ms on September 24, 2020, 10:19:33 PM
Maybe I missed it...have you tried a new solenoid? In my experience they can do freaky things like coils. Had a weird thing a few years ago where my 66 just kept running when the key was turned off. At first I was convinced it was the ignition switch. Nope, it was the solenoid.
No. I'm going to try the larger gauge cables first, then the only thing left is the starter solinoid.
Parameters. One thing at a time. You shouldn't "multi-task" with mechanical devices.
With all of this talk about starters and solenoids could you clarify on how the the engine acts when you are trying to start . Does the engine spin but does not fire when it is hot ? Does the starter drag when it is hot or does the engine spin but will not fire? Clarification will help with diagnosis. With the first few posts talking about coils ,points and tachs it read like a engine firing issue and not a engine spinning issue. Typically two separate unrelated issues. The starter , cables ,and solenoid typically have to do with the engine dragging when hot or not spinning at all. Those things are typically unrelated to a engine not firing situation.
Quote from: Bob Gaines on September 25, 2020, 10:27:26 AM
With all of this talk about starters and solenoids could you clarify on how the the engine acts when you are trying to start . Does the engine spin but does not fire when it is hot ? Does the starter drag when it is hot or does the engine spin but will not fire? Clarification will help with diagnosis. With the first few posts talking about coils ,points and tachs it read like a engine firing issue and not a engine spinning issue. Typically two separate unrelated issues. The starter , cables ,and solenoid typically have to do with the engine dragging when hot or not spinning at all. Those things are typically unrelated to a engine not firing situation.
Sure. It spins the same as when cold, I would describe as normally.
The timing light shows the #1 firing "rapidly" when cold, but much less, when engine is warm. Maybe in the 25% to 33% of when cold.
Consequentially, you can here it fire like it wants to start, but it needs to really be cranked to a point where the solenoid on the firewall gets so hot, it will start to smoke.
The starter is not laboring at all. The tach shows it spinning the engine at about 750 to 800 rpm at that point.
Quote from: shelbydoug on September 25, 2020, 11:50:39 AM
Quote from: Bob Gaines on September 25, 2020, 10:27:26 AM
With all of this talk about starters and solenoids could you clarify on how the the engine acts when you are trying to start . Does the engine spin but does not fire when it is hot ? Does the starter drag when it is hot or does the engine spin but will not fire? Clarification will help with diagnosis. With the first few posts talking about coils ,points and tachs it read like a engine firing issue and not a engine spinning issue. Typically two separate unrelated issues. The starter , cables ,and solenoid typically have to do with the engine dragging when hot or not spinning at all. Those things are typically unrelated to a engine not firing situation.
Sure. It spins the same as when cold, I would describe as normally.
The timing light shows the #1 firing "rapidly" when cold, but much less, when engine is warm. Maybe in the 25% to 33% of when cold.
Consequentially, you can here it fire like it wants to start, but it needs to really be cranked to a point where the solenoid on the firewall gets so hot, it will start to smoke.
The starter is not laboring at all. The tach shows it spinning the engine at about 750 to 800 rpm at that point.
Your clarification indicates to me that there is apparently no relation between the starter,cables or solenoid to the engine not firing regardless of if hot or cold. I would be interested in hearing how those starter related items have any relation to engine ignition and firing before going down that rabbit hole further.
I agree with Bob. Doesn't sound like a starter/battery/solenoid issue.
I would guess heat related issue with fuel and combustion. Maybe
isolating/insulation fuel lines, carb mount insulator would help.
Quote from: shelbydoug on September 24, 2020, 02:35:54 PM
I will say the wires do get HOT and the solenoid can wind up smoking. :o
Regardless of whether it solves the starting issue, apparently something needs to done as the circuit is being overloaded, ..................and that's how fires get started! :o
Often, if familiar, one can detect as the starter motor is cranking the engine, of the sound, as if it were creating a high draw to the point of a significant voltage drop, that being on an otherwise well charge and sound electrical system as this can be of some rather great amperage sums.
Check the amperage draw upon starter engagement and cranking as cooking the leads (of reasonable capacity and duration) is a subject that should be investigated, as just bigger wires, is somewhat like "fixing" the recurring blown fuse in the home with the installation of one of greater amperage rating. ::)
Scott.
Quote from: Tom Honegger on September 25, 2020, 01:05:00 PM
I agree with Bob. Doesn't sound like a starter/battery/solenoid issue.
I would guess heat related issue with fuel and combustion. Maybe
isolating/insulation fuel lines, carb mount insulator would help.
When engine is hot, carbs are cool to the touch as is fuel line which is phenolicly isolated as are carbs.
As I said, coil not firing hot. Fuel not percolating and starting fluid does nothing.
In addition, the COIL is phenolicly isolated as well.
Ignition all the way...but why? That's the question.
Is this the same car you replaced the resistor wire on? I would check the coil voltage when cranking hot vs cold, and running hot vs cold. Did you use good quality points and condensor? Lots of Chinese junk out there. I try to stay with Motorcraft or Echlin. A faulty condensor can act up when hot.
Quote from: KR Convertible on September 25, 2020, 02:52:53 PM
Is this the same car you replaced the resistor wire on? I would check the coil voltage when cranking hot vs cold, and running hot vs cold. Did you use good quality points and condensor? Lots of Chinese junk out there. I try to stay with Motorcraft or Echlin. A faulty condensor can act up when hot.
Resistor wire...yes.
Echlin points and condenser.
Was doing same thing with Petronix with 12v non-resistor wire.
Checking the coil voltage cranking...yes would confirm the issue, but no, not yet. That doesn't eliminate the solenoid either. Waiting on my 00's.
Will check that all when they get installed.
Quote from: shelbydoug on September 25, 2020, 05:13:35 PM
Quote from: KR Convertible on September 25, 2020, 02:52:53 PM
Is this the same car you replaced the resistor wire on? I would check the coil voltage when cranking hot vs cold, and running hot vs cold. Did you use good quality points and condensor? Lots of Chinese junk out there. I try to stay with Motorcraft or Echlin. A faulty condensor can act up when hot.
Resistor wire...yes.
Echlin points and condenser.
Was doing same thing with Petronix with 12v non-resistor wire.
Checking the coil voltage cranking...yes would confirm the issue, but no, not yet. Waiting on my 00's.
If you put 12v to a yellow top coil for any extended length of time you may have damaged it . It will get hot and damage the internals. I have seen them explode. Try another yellow top or petronix coil.
Quote from: Bob Gaines on September 25, 2020, 05:16:46 PM
Quote from: shelbydoug on September 25, 2020, 05:13:35 PM
Quote from: KR Convertible on September 25, 2020, 02:52:53 PM
Is this the same car you replaced the resistor wire on? I would check the coil voltage when cranking hot vs cold, and running hot vs cold. Did you use good quality points and condensor? Lots of Chinese junk out there. I try to stay with Motorcraft or Echlin. A faulty condensor can act up when hot.
Resistor wire...yes.
Echlin points and condenser.
Was doing same thing with Petronix with 12v non-resistor wire.
Checking the coil voltage cranking...yes would confirm the issue, but no, not yet. Waiting on my 00's.
If you put 12v to a yellow top coil for any extended length of time you may have damaged it . It will get hot and damage the internals. I have seen them explode. Try another yellow top or petronix coil.
I'm running the resistor wire to it which reduces the voltage. That was the point on installing a new resistor wire.
Quote from: shelbydoug on September 25, 2020, 05:31:30 PM
Quote from: Bob Gaines on September 25, 2020, 05:16:46 PM
Quote from: shelbydoug on September 25, 2020, 05:13:35 PM
Quote from: KR Convertible on September 25, 2020, 02:52:53 PM
Is this the same car you replaced the resistor wire on? I would check the coil voltage when cranking hot vs cold, and running hot vs cold. Did you use good quality points and condensor? Lots of Chinese junk out there. I try to stay with Motorcraft or Echlin. A faulty condensor can act up when hot.
Resistor wire...yes.
Echlin points and condenser.
Was doing same thing with Petronix with 12v non-resistor wire.
Checking the coil voltage cranking...yes would confirm the issue, but no, not yet. Waiting on my 00's.
If you put 12v to a yellow top coil for any extended length of time you may have damaged it . It will get hot and damage the internals. I have seen them explode. Try another yellow top or petronix coil.
I'm running the resistor wire to it which reduces the voltage. That was the point on installing a new resistor wire.
I misunderstood reply #29 where you said "Was doing same thing with Petronix with 12v non-resistor wire.'" I thought you were running the Petronix module in the dist and a yellow top coil off of 12V. Thanks for clarifying .Check that off a possible culprit.
Quote from: Bob Gaines on September 25, 2020, 06:07:42 PM
Quote from: shelbydoug on September 25, 2020, 05:31:30 PM
Quote from: Bob Gaines on September 25, 2020, 05:16:46 PM
Quote from: shelbydoug on September 25, 2020, 05:13:35 PM
Quote from: KR Convertible on September 25, 2020, 02:52:53 PM
Is this the same car you replaced the resistor wire on? I would check the coil voltage when cranking hot vs cold, and running hot vs cold. Did you use good quality points and condensor? Lots of Chinese junk out there. I try to stay with Motorcraft or Echlin. A faulty condensor can act up when hot.
Resistor wire...yes.
Echlin points and condenser.
Was doing same thing with Petronix with 12v non-resistor wire.
Checking the coil voltage cranking...yes would confirm the issue, but no, not yet. Waiting on my 00's.
If you put 12v to a yellow top coil for any extended length of time you may have damaged it . It will get hot and damage the internals. I have seen them explode. Try another yellow top or petronix coil.
I'm running the resistor wire to it which reduces the voltage. That was the point on installing a new resistor wire.
I misunderstood reply #29 where you said "Was doing same thing with Petronix with 12v non-resistor wire.'" I thought you were running the Petronix module in the dist and a yellow top coil off of 12V. Thanks for clarifying .Check that off a possible culprit.
No problem at all. It is confusing to say the least.
I said to myself, "the answer is going to be something stupid, i.e., something uncommon and simple to overlook".
The voltage drop to the coil, is likely the answer. If the simple fix is larger cables, then great. It would be great to have a modern ignition that drops the initial advance down to make it easier to start. I can definitely see that as an advantage on a warm engine.
I'm wondering still if I cooked the solenoid too? The tach dropped out of normal operation in all of this just to add to the frustration?
Always remember, "it's always in the last place you look?" ;)
Can you get pure gas anywhere near you? I would try that.
https://www.pure-gas.org/
Quote from: deathsled on September 30, 2020, 08:56:37 PM
Can you get pure gas anywhere near you? I would try that.
https://www.pure-gas.org/
Not in New York. Only 10% ethanol.
Quote from: shelbydoug on October 01, 2020, 09:46:24 AM
Quote from: deathsled on September 30, 2020, 08:56:37 PM
Can you get pure gas anywhere near you? I would try that.
https://www.pure-gas.org/
Not in New York. Only 10% ethanol.
Plenty of Stewart's Shops in upstate NY sell non- ethanol gas, among others.
Maybe, but not here.
It doesn't matter. You HAVE to build and tune the car to run on pump gas WHATEVER that might be, otherwise I'd still be running around with SUNOCO 106 leaded! ;)
That would be great. The car would be idling way down at probably 500 rpm's and running cool.
Another vote for larger cables. on my '69 428, never cranked hot. I had access to welding cables, so made up a full set of 1/0 cables, and a new quality solenoid, cranked fast every time.
I also had an electronic ignition, so that helped in the spark department.
I just had the starter wire and battery ground done in 2/0. It's a bit of overkill and PROBABLY 1/0 is plenty?
I got delayed on a full trial but so far I can tell you that I seem to have picked up some rpm starting AND the big cables aren't getting hot so stay tuned to this station!
Check the coil cable?
Quote from: gt350bp on October 02, 2020, 07:01:55 PM
Check the coil cable?
I replaced the wiring to the coil all the way to the ignition switch and the starter solenoid.
Good luck I hope that works for you nothing worse than having to guess wether your car is going to start every time you turn the key
The modern gear reduction starter like from power master should draw a lot less amps to turn the engine over right?
Quote from: tonys_shelby on October 03, 2020, 07:06:13 AM
The modern gear reduction starter like from power master should draw a lot less amps to turn the engine over right?
Correct.