Ignition timing setting tutorial
#1
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Year: 1996
Model: Cherokee
Engine: 4.0 Lt HO
Ignition timing setting tutorial
Hi,
i just found my dads ignition timing gun. Its pretty vintage. But im just curious how to use it. Is there any tutorial for how to use it on a cherokee? And maybe how to do the proper firing timing adjustment.
Cheers
i just found my dads ignition timing gun. Its pretty vintage. But im just curious how to use it. Is there any tutorial for how to use it on a cherokee? And maybe how to do the proper firing timing adjustment.
Cheers
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Year: 1999
Model: Cherokee
Engine: 4.0
Actually, I read somewhere that a dude used one of these timing lights to check his ignition wires/plugs. With the light pickup attached to a plug wire and the motor running, he shined the light on a piece of white paper and watched the strobe intensity and checked for consistant flashing. He did this with each plug wire.
It may be useful trying to chase down a misfire at idle(?).
I have a timing light left over from 'the old days'. Don't know if this works or not but I'm curious enough to see how it does.
It may be useful trying to chase down a misfire at idle(?).
I have a timing light left over from 'the old days'. Don't know if this works or not but I'm curious enough to see how it does.
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Year: 1995
Model: Grand Cherokee
Engine: 4.0 with all of the noise and clatter
Actually, I read somewhere that a dude used one of these timing lights to check his ignition wires/plugs. With the light pickup attached to a plug wire and the motor running, he shined the light on a piece of white paper and watched the strobe intensity and checked for consistant flashing. He did this with each plug wire. It may be useful trying to chase down a misfire at idle(?). I have a timing light left over from 'the old days'. Don't know if this works or not but I'm curious enough to see how it does.
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#8
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Year: 1996
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#9
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Year: 1985
Model: Cherokee
Engine: 2.5L
I have been using a timing light a lot lately, since my 85 2.5l has adjustable timing. Experimenting with taking it up to 18degrees advance. Probably back it off a little to see if that helps the mileage on this winter blend gas though.
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Red and black go to the battery.
Green goes to ignition coil (-) for checking dwell (back when ignitions used "points"- basically a switch to fire the coil), don't need to connect that one to use the timing light.
Pull the trigger and point the light at the harmonic balancer on the front of the motor. You should see the mark on the balancer appearing to stand still- that indicates your timing advance against a a marked tab attached to the block.
As mentioned, you can't adjust the timing- the computer does it for you. But you can look.
Last edited by Radi; 03-03-2014 at 01:16 AM.
#11
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Year: 1990
Model: Comanche
Engine: 4.0
If you want to try it out, the inductive clip goes over the #1 sparkplug wire. There should be an arrow on the clip that points towards the sparkplug.
Red and black go to the battery.
Green goes to ignition coil (-) for checking dwell (back when ignitions used "points"- basically a switch to fire the coil), don't need to connect that one to use the timing light.
Pull the trigger and point the light at the harmonic balancer on the front of the motor. You should see the mark on the balancer appearing to stand still- that indicates your timing advance against a a marked tab attached to the block.
As mentioned, you can't adjust the timing- the computer does it for you. But you can look.
Red and black go to the battery.
Green goes to ignition coil (-) for checking dwell (back when ignitions used "points"- basically a switch to fire the coil), don't need to connect that one to use the timing light.
Pull the trigger and point the light at the harmonic balancer on the front of the motor. You should see the mark on the balancer appearing to stand still- that indicates your timing advance against a a marked tab attached to the block.
As mentioned, you can't adjust the timing- the computer does it for you. But you can look.
Also, might not need mentioning, but you do need to hook the red and black to the battery + and - respectively. Since it is a dwell-tach, if it were a Renix system, you could connect the green clip to a pin inserted in the #1 connection in the smallest diagnostic socket to be able to read the engine RPM while you're under the hood. The small switch below the meter would be pushed to the right and read the RPMs on the lower part of the upper scale for your six cylinder.
I don't know anything about '91 and newer, so don't know if there's anywhere you can connect for RPM on your '96.
Last edited by Bobolink; 03-03-2014 at 09:07 AM.
#12
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Year: 1997
Model: Cherokee
Engine: 4.0L
I've had an intermittent misfire at idle for a long time. I'm going to try this trick to see if it's electrical or maybe a dirty fuel injector. I wonder if the pickup would sense the injectors firing if connected to their wires. Once again, thanks.
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