correct plugs and wires for points type distributor on 140 engine

Chevyls6

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I think ive finally gotten my fuel/vacuum leak issues sorted. Now i'm having trouble with the ignition.

Are these old points distributors supposed to have resistor plug wires?

What is the interchange for the ac delco cr44N plugs that my manual calls for?

Currently my setup has ac delco mr43t plugs with aftermarket resistor plug wires.

Another issue i noticed is the positive side of the distributor is getting full battery voltage with the key in the run position. Where is the ballast resistor on these engines?

Would it be worth throwing all this stuff in the trash and going electronic ignition ?
 

achris

More fish than mountain goat
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May 19, 2004
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I think ive finally gotten my fuel/vacuum leak issues sorted. Now i'm having trouble with the ignition.

Are these old points distributors supposed to have resistor plug wires?

What is the interchange for the ac delco cr44N plugs that my manual calls for?

Currently my setup has ac delco mr43t plugs with aftermarket resistor plug wires.

Another issue i noticed is the positive side of the distributor is getting full battery voltage with the key in the run position. Where is the ballast resistor on these engines?

Would it be worth throwing all this stuff in the trash and going electronic ignition ?
Engine model, year and serial number?
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
Staff member
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Jul 23, 2011
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50,360
I think ive finally gotten my fuel/vacuum leak issues sorted. Now i'm having trouble with the ignition.

Are these old points distributors supposed to have resistor plug wires?

What is the interchange for the ac delco cr44N plugs that my manual calls for?

Currently my setup has ac delco mr43t plugs with aftermarket resistor plug wires.

Another issue i noticed is the positive side of the distributor is getting full battery voltage with the key in the run position. Where is the ballast resistor on these engines?

Would it be worth throwing all this stuff in the trash and going electronic ignition ?
only you can answer if spending $400 for a new Delco Voyager EST ignition is worth it. to me, 5 minutes every spring to run a file thru them and using the dwell meter to set the dwell was just the extra step in spring time commissioning

your harness has the resistor wire in it (assuming your harness has not been butchered)
 

dubs283

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5,333
Now i'm having trouble with the ignition.
What kind of trouble/issues?
Another issue i noticed is the positive side of the distributor is getting full battery voltage with the key in the run position. Where is the ballast resistor on these engines?
As stated the resistor for the coil primary (+) is a resistor wire in the factory harness, no external resistor. If you are seeing battery voltage at the (+) side of the coil with key on engine not running or cranking there is a chance either the resistor wire has failed or someone abated it. Generally speaking one likes to see roughly 2-3 volts less than battery voltage static/running at the coil primary on a conventional (points) ignition
 

achris

More fish than mountain goat
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Another issue i noticed is the positive side of the distributor is getting full battery voltage with the key in the run position.
If the points are open when you measure the voltage then you will see full voltage, even if there were 10 ballast resistors in the line... Measure the voltage with the points closed and you'll get about 7v.

Chris ..
 

Bt Doctur

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Aug 29, 2004
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unless the coil is rated for the full 12v and does not say on its side "use ballast resistor" it used full 12v because the coil is internally ballasted
 

Chevyls6

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only you can answer if spending $400 for a new Delco Voyager EST ignition is worth it. to me, 5 minutes every spring to run a file thru them and using the dwell meter to set the dwell was just the extra step in spring time commissioning

your harness has the resistor wire in it (assuming your harness has not been butchered)
I was more considering the pertronix electronic trigger kit for around $80.
 

Scott Danforth

Grumpy Vintage Moderator still playing with boats
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I was more considering the pertronix electronic trigger kit for around $80.
good luck, I tried pertronix twice and went back to points when they failed. a few others on this site had same issue.
 

Chevyls6

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What kind of trouble/issues?

As stated the resistor for the coil primary (+) is a resistor wire in the factory harness, no external resistor. If you are seeing battery voltage at the (+) side of the coil with key on engine not running or cranking there is a chance either the resistor wire has failed or someone abated it. Generally speaking one likes to see roughly 2-3 volts less than battery voltage static/running at the coil primary on a conventional (points) ignition

I've got a misfire at idle and backfiring when i rev it up. What tipped me off that it may be ignition related is when i put my inductive tach on the number 1 plug wire it reads some ridiculous value like 50rpm but the other cylinders read 800.

If i check the coil positive when disconnected its 12.60v but connect im only getting 5v.
 

Chevyls6

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If the points are open when you measure the voltage then you will see full voltage, even if there were 10 ballast resistors in the line... Measure the voltage with the points closed and you'll get about 7v.

Chris ..
I'm getting battery voltage when the circuit is open and 5v when its closed
 

Chevyls6

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Does anyone know what the correct spark plug wire resistance should be? These wire came in a cheap ebay tune up kit so they may be bad.
 

achris

More fish than mountain goat
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Does anyone know what the correct spark plug wire resistance should be? These wire came in a cheap ebay tune up kit so they may be bad.
With plug wires a adopt a 'if in doubt, throw it out' policy.

Local car shop, 8mm silicone wires, you can't go wrong.

Chris......
 

Chevyls6

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I think i may have found the issue. The contacts inside the distributor cap were so loose that they rotated enough that one of them seems to have touched the rotor.

Never again with the cheap tune up kits.
 

achris

More fish than mountain goat
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I think i may have found the issue. The contacts inside the distributor cap were so loose that they rotated enough that one of them seems to have touched the rotor.

Never again with the cheap tune up kits.
Ah yes, the old 'it's cheap, let's save money'....

Old Chinese proverb. "Cheap no good, good no cheap".
 
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