Volvo penta aq131a spark problem

Benjamin1979

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Mar 6, 2016
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I've got no spark from plugs so I tested coil wire got nothing tested coil ive got constant hot going in i should have a constant hot coming out of the coil to the coil wire and I dont im pretty sure ive got a bad coil but I thought I would check with you guys to make sure im not missing something.
 

dennis461

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Aug 11, 2011
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You need to check many more things, do you know how to check gap in points with #1 cylinder at top dead center?
 

Bondo

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Ayuh,..... Welcome Aboard,.... The points ground out the coil, causin' it to Spark,.....

They're probably glazed over with corrosion,.....
 

jerryjerry05

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May 7, 2008
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18,147
The coil operates on 9v.
There is a voltage regulator or resistor in the system.
It takes 12v from the battery and breaks it down to 9v.
You should get 9v through the coil while turning over.
It will read 9v then go way down then 9v again as the points fire the plugs.

No spark usually means the points need filing/ sanding.
Sometimes they can't be saved and need to be replaced???
THe condenser can also go bad(not often)but can happen.
 

Bondo

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I filed off points still no spark

Ayuh,.... Is there power at the points,..??

Power from the coil's (-) terminal goes to one side of the points, 'n the other side has to have a good ground,....

When ya wiggle the points, with the key On, there oughta be tiny sparks at the point faces,....
 

bruceb58

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Mar 5, 2006
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You need to check many more things, do you know how to check gap in points with #1 cylinder at top dead center?
You don't need the engine at TDC to check the points gap. The point just have to be at the high point of the distributor cam lobe.

Buy a dwell meter and set the points that way.


I would do this set of tests.

1) with the points open and ignition on, measure the voltage at the + side of the coil to ground. Should be 12V.
2) rotate the engine until the points are closed. Measure the voltage form the + side of the coil to ground. Should be between 7V and 9V.

I would buy a new set of points and condensor and set the dwell using a dwell meter after first setting the gap to get close with a feeler gauge.
 

dennis461

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Aug 11, 2011
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516
You don't need the engine at TDC to check the points gap. The point just have to be at the high point of the distributor cam lobe.

Buy a dwell meter and set the points that way.


I would do this set of tests.

1) with the points open and ignition on, measure the voltage at the + side of the coil to ground. Should be 12V.
2) rotate the engine until the points are closed. Measure the voltage form the + side of the coil to ground. Should be between 7V and 9V.

I would buy a new set of points and condensor and set the dwell using a dwell meter after first setting the gap to get close with a feeler gauge.


I posted that question to the OP and got the answer, he has no clue (his words), So he will most likely not know what a dwell meter is or how to use it.
(and it wont do him any good if the engine is not running?
 

bruceb58

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I posted that question to the OP and got the answer, he has no clue (his words), So he will most likely not know what a dwell meter is or how to use it.
(and it wont do him any good if the engine is not running?
You can crank the engine and get a dwell reading that is very close even if the engine doesn't start. Still way better than setting it with just a gap.

Another thing that using a dwell meter tells you(even while just cranking) is that all the wiring between the coil to the distributor and points and then to ground is ok.

You do agree that you don't need to check the gap at #1 TDC right?
 
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