No start when hot and using key.
#2697998
09/16/19 10:13 AM
09/16/19 10:13 AM
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Joined: Jan 2003
Posts: 4,051 Connecticut
jeff968
OP
master
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OP
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Joined: Jan 2003
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Connecticut
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Hi, I'm still battling this issue and thought I would ask the Moparts gang for any thoughts. Here is the deal.
When my Challenger is cold it always starts. When it gets warm and I shut it off and it sits for a while it won't start. The car turns over but it is not getting any spark when the engine is turning over. If I just leave the key forward (not under load) and jump it with a screwdriver on the start relay it starts.
So the "no spark" issue is only under load (key all the way forward, engine turning).
I had upgraded to Electronic ignition. I have a new ECM, ballast resistor, starter relay, plug wires, cap, and engine compartment wiring harness. I even replaced the bulkhead with all new connectors. The positive side of the coil shows it is getting power.
I'm thinking of replacing the distributor next.
Thanks for any suggestions.
1970 Dodge Challenger T/A
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Re: No start when hot and using key.
[Re: Andrewh]
#2698037
09/16/19 11:46 AM
09/16/19 11:46 AM
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Joined: Nov 2003
Posts: 36,040 Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
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What Andrew said, start at the ign switch/connector & clean the terminals.
live every 24 hour block of time like it's your last day on earth
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Re: No start when hot and using key.
[Re: burdar]
#2698082
09/16/19 01:43 PM
09/16/19 01:43 PM
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Joined: Jan 2003
Posts: 4,051 Connecticut
jeff968
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OP
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Connecticut
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Thanks! I will check these.
As I said earlier, I installed a brand new bulkhead and redid all the connectors. It still had the same issue.
1970 Dodge Challenger T/A
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Re: No start when hot and using key.
[Re: Andrewh]
#2698105
09/16/19 02:51 PM
09/16/19 02:51 PM
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Joined: Jan 2003
Posts: 4,051 Connecticut
jeff968
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OP
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Posts: 4,051
Connecticut
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I had the column done by SMS 12 years ago so no. But that said, I have a brand new ignition switch. When I plug that in it has the same problem. So I don't believe the ignition switch is the issue. Thx
1970 Dodge Challenger T/A
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Re: No start when hot and using key.
[Re: Andrewh]
#2698124
09/16/19 03:58 PM
09/16/19 03:58 PM
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Joined: Nov 2003
Posts: 36,040 Lincoln Nebraska
RapidRobert
Circle Track
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Circle Track
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
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somewhere from the ign sw, brown wire (ign2) circuit out to the coil positive primary & or to the blue/yellow wire "power in" terminal at the ECU there is a part time open. EDIT & when you jump it at the relay & it fires (with key "on") you are immediately jumping it when it is still hot/not firing correct? (no cool down?)
Last edited by RapidRobert; 09/16/19 04:01 PM.
live every 24 hour block of time like it's your last day on earth
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Re: No start when hot and using key.
[Re: mrob]
#2698169
09/16/19 06:25 PM
09/16/19 06:25 PM
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Joined: Feb 2003
Posts: 8,671
Andrewh
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I have been thinking about this for a while and it had me stumped for a bit.
normally power is only applied to that circuit from the key in start.
however, once in run, it could back feed from the ballast back to the ignition. now normally this isn't an issue because it could not complete the circuit since the ignition is in run, and even if it were not, there should be no path to ground since it is the hot side of the circuit.
But if one of your connectors is not right and has a partial ground going, enough to heat it up and make it act like a bimetalic, that might explain your symptoms.
While it might not be the switch itself, how does the connector look at the ignition? or at the column? how much of that is new?
If I am right, you don't even have to run the car, just set it in run for however long it would normally take to cause this to happen. It is also possible to test in run and not bother with start, as you will see power up till the break from the back feed.
again just a guess, but the only one I can think of. one of the wires might also have an insulation problem, something with a wear in it so only 1 strand is touching the coulnm not enough to blow a fuse, or melt the line, (not even sure if it is fused). since it only gets 12 volts on start and the backfeed would be the 5 or 8 volts to the coil.
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