|
Weak to no Spark, all of a sudden*****UPDATE****
#2716463
11/16/19 04:38 PM
11/16/19 04:38 PM
|
Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
Sammy
OP
top fuel
|
OP
top fuel
Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
|
1968 Dart.
Weak to no spark . Car started up this morning barely idled but kept cutting out.
Pulled the plugs and they were wet. Replaced the plugs and car still wont fire up.
Pulled a plug and watched for spark with ignition on the on position and its barely there and then none.
It has a stock distributor converted to Pertronix electronic no points.
Where do I go from here?
Last edited by Sammy; 11/20/19 07:41 PM.
|
|
|
Re: Weak to no Spark, all of a sudden
[Re: Sniper]
#2716474
11/16/19 05:11 PM
11/16/19 05:11 PM
|
Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
Sammy
OP
top fuel
|
OP
top fuel
Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
|
What's the voltage at the coil + terminal? With the key in the on position. Positive red lead from volt meter black wire to battery ground, I get 5.3 volts
|
|
|
Re: Weak to no Spark, all of a sudden
[Re: Sammy]
#2716492
11/16/19 06:08 PM
11/16/19 06:08 PM
|
Joined: May 2019
Posts: 6,221
nowhere
Sniper
master
|
master
Joined: May 2019
Posts: 6,221
nowhere
|
When out to the 51 and took some measurements. It's a 51 Plymouth Cambridge I converted to 12v negative ground using a Mopar alternator and voltage regulator. Stock points ignition with Mopar ballast and 12v coil. engine off, key in run I see 12.2V at the battery (low, should be 12.8v ish) and 6.2v at the coil +, all grounds taken at the battery negative terminal. engine running, 12.8V at the battery (low, should be 13.8v ish, need to up the idle speed) and 8.8v at the coil +, all grounds taken at the battery negative terminal. Pertronix says 8.0v minimum. You barely have the minimum for a 6v system. You aren't still running the ballast? A LINK to the Pertronix test pdf. For some reason your voltage at the coil is way low.
|
|
|
Re: Weak to no Spark, all of a sudden
[Re: Sniper]
#2716521
11/16/19 07:36 PM
11/16/19 07:36 PM
|
Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
Sammy
OP
top fuel
|
OP
top fuel
Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
|
When out to the 51 and took some measurements. It's a 51 Plymouth Cambridge I converted to 12v negative ground using a Mopar alternator and voltage regulator. Stock points ignition with Mopar ballast and 12v coil. engine off, key in run I see 12.2V at the battery (low, should be 12.8v ish) and 6.2v at the coil +, all grounds taken at the battery negative terminal. engine running, 12.8V at the battery (low, should be 13.8v ish, need to up the idle speed) and 8.8v at the coil +, all grounds taken at the battery negative terminal. Pertronix says 8.0v minimum. You barely have the minimum for a 6v system. You aren't still running the ballast? A LINK to the Pertronix test pdf. For some reason your voltage at the coil is way low. Not really sure how to proceed at this point. Ballast resistor is there as is the voltage regulator. its a stock distributor with Pertronix conversion to electronic ignition. Car did start up initially but was running horribly. Plugs were fouled. Changed plugs out and it doesn't even want to run. Like I said, virtually a faint to no spark.
|
|
|
Re: Weak to no Spark, all of a sudden
[Re: Sniper]
#2716533
11/16/19 08:14 PM
11/16/19 08:14 PM
|
Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
Sammy
OP
top fuel
|
OP
top fuel
Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
|
With the key on, engine off what's the voltage on both sides of the ballast?
One side had better be real close to battery voltage. that side comes from the ignition switch. Going to check and see what it is. What voltage on both sides??
|
|
|
Re: Weak to no Spark, all of a sudden
[Re: Alaskan_TA]
#2716534
11/16/19 08:16 PM
11/16/19 08:16 PM
|
Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
Sammy
OP
top fuel
|
OP
top fuel
Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
|
Pertronix failures are common.
Did you use their coil also?
If so, swap the old one back in & try it. Only did the conversion with the distributor. Everything else is concours correct with dated coded parts.
|
|
|
Re: Weak to no Spark, all of a sudden
[Re: Sammy]
#2716556
11/16/19 09:55 PM
11/16/19 09:55 PM
|
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
RapidRobert
Circle Track
|
Circle Track
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
|
Only did the conversion with the distributor. Jump 12V to the Pertronix & if no go then its the P conversion in the dist that's at fault
live every 24 hour block of time like it's your last day on earth
|
|
|
Re: Weak to no Spark, all of a sudden
[Re: Sammy]
#2716557
11/16/19 09:56 PM
11/16/19 09:56 PM
|
Joined: Aug 2003
Posts: 43,112
Bend,OR USA
Cab_Burge
I Win
|
I Win
Joined: Aug 2003
Posts: 43,112
Bend,OR USA
|
The ballast resistor has two feeds from the ignition switch, one from the run position and one from the start position for feeding the coil + side 12.+ V when the starter is engaged. Once you turn the ignition switch in the run position you should see 12.+ volts on one side of the ballast resistor and around 6.0 to 8.0 volts on the other side going to the + side of the coil.  You should also see 12.+ V on the + side of the coil when you have the ignition switch in the start position also If you have both of those voltage I would think the Pertronix module is the problem   Do you have a trouble shooting procedure for the Pertronix unit?
Last edited by Cab_Burge; 11/16/19 09:57 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
|
|
|
Re: Weak to no Spark, all of a sudden
[Re: Cab_Burge]
#2716564
11/16/19 10:14 PM
11/16/19 10:14 PM
|
Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
Sammy
OP
top fuel
|
OP
top fuel
Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
|
The ballast resistor has two feeds from the ignition switch, one from the run position and one from the start position for feeding the coil + side 12.+ V when the starter is engaged. Once you turn the ignition switch in the run position you should see 12.+ volts on one side of the ballast resistor and around 6.0 to 8.0 volts on the other side going to the + side of the coil. You should also see 12.+ V on the + side of the coil when you have the ignition switch in the start position also If you have both of those voltage I would think the Pertronix module is the problem Do you have a trouble shooting procedure for the Pertronix unit? Only getting 5.5 at the positive side of the could in the on position. Is there a way to bypass the ballast resistor temporarily to see if the car starts? If I dont have 12 volts at the ballast resistor, what is the fix for this?
|
|
|
Re: Weak to no Spark, all of a sudden
[Re: RapidRobert]
#2716565
11/16/19 10:15 PM
11/16/19 10:15 PM
|
Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
Sammy
OP
top fuel
|
OP
top fuel
Joined: Dec 2012
Posts: 1,823
Wind Gap,Pa.
|
Only did the conversion with the distributor. Jump 12V to the Pertronix & if no go then its the P conversion in the dist that's at fault Take a lead from the positive side of the battery and go to which wire on the distributor?
|
|
|
Re: Weak to no Spark, all of a sudden
[Re: Sammy]
#2716567
11/16/19 10:21 PM
11/16/19 10:21 PM
|
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
RapidRobert
Circle Track
|
Circle Track
Joined: Nov 2003
Posts: 36,040
Lincoln Nebraska
|
the one going to the coil positive primary terminal
live every 24 hour block of time like it's your last day on earth
|
|
|
Re: Weak to no Spark, all of a sudden
[Re: Sammy]
#2716569
11/16/19 10:30 PM
11/16/19 10:30 PM
|
Joined: May 2019
Posts: 6,221
nowhere
Sniper
master
|
master
Joined: May 2019
Posts: 6,221
nowhere
|
With the key on, engine off what's the voltage on both sides of the ballast?
One side had better be real close to battery voltage. that side comes from the ignition switch. Going to check and see what it is. What voltage on both sides?? just tell us what you got then we can go from there.
|
|
|
Re: Weak to no Spark, all of a sudden
[Re: Sammy]
#2716609
11/17/19 03:21 AM
11/17/19 03:21 AM
|
Joined: Aug 2003
Posts: 43,112
Bend,OR USA
Cab_Burge
I Win
|
I Win
Joined: Aug 2003
Posts: 43,112
Bend,OR USA
|
The ballast resistor has two feeds from the ignition switch, one from the run position and one from the start position for feeding the coil + side 12.+ V when the starter is engaged. Once you turn the ignition switch in the run position you should see 12.+ volts on one side of the ballast resistor and around 6.0 to 8.0 volts on the other side going to the + side of the coil. You should also see 12.+ V on the + side of the coil when you have the ignition switch in the start position also If you have both of those voltage I would think the Pertronix module is the problem Do you have a trouble shooting procedure for the Pertronix unit? Only getting 5.5 at the positive side of the could in the on position. Is there a way to bypass the ballast resistor temporarily to see if the car starts? If I dont have 12 volts at the ballast resistor, what is the fix for this? This is normal, now get someone to hold the ignition switch in the start position after you are ready to read the voltage going to the + side of the coil when the starter is wroking let us know that voltage  Did you check the voltage on both sides of the ballast resistor with the ignition switch on? If not do that, one side should read around 12.+volts and the other side should read less than 8.0 Volts if you check it before it warms up and creates more resistance which will read less voltage like you have seen.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
|
|
|
Re: Weak to no Spark, all of a sudden
[Re: Cab_Burge]
#2716624
11/17/19 09:32 AM
11/17/19 09:32 AM
|
Joined: May 2019
Posts: 6,221
nowhere
Sniper
master
|
master
Joined: May 2019
Posts: 6,221
nowhere
|
The ballast resistor has two feeds from the ignition switch, one from the run position and one from the start position for feeding the coil + side 12.+ V when the starter is engaged. Once you turn the ignition switch in the run position you should see 12.+ volts on one side of the ballast resistor and around 6.0 to 8.0 volts on the other side going to the + side of the coil. You should also see 12.+ V on the + side of the coil when you have the ignition switch in the start position also If you have both of those voltage I would think the Pertronix module is the problem Do you have a trouble shooting procedure for the Pertronix unit? Only getting 5.5 at the positive side of the could in the on position. Is there a way to bypass the ballast resistor temporarily to see if the car starts? If I dont have 12 volts at the ballast resistor, what is the fix for this? This is normal, now get someone to hold the ignition switch in the start position after you are ready to read the voltage going to the + side of the coil when the starter is wroking let us know that voltage Did you check the voltage on both sides of the ballast resistor with the ignition switch on? If not do that, one side should read around 12.+volts and the other side should read less than 8.0 Volts if you check it before it warms up and creates more resistance which will read less voltage like you have seen.
|
|
|
|
|
