What is voltage to injector on '87 tb - JeepForum.com
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post #1 of 4 Old 04-06-2013, 03:27 PM Thread Starter
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1987 YJ Wrangler 
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What is voltage to injector on '87 tb

What voltage reading should I get at the injector connection on a 1987 2.5 w/TBI. My voltage reads 3.6v with ignition in "ON" position. I have heard it should be 5v by some and 12v by others. If voltage is 12v could I connect a 12v source with ignition "ON" and splice it into injector connection?

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post #2 of 4 Old 04-06-2013, 07:36 PM
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According to this diagram I found on a Russian website, you should have 12V on the orange wire, which is fed through your fuel pump relay (if you're keeping it stock). The ECU supplies the ground pulses on the Light Blue wire, pin #21 on your ECU.

Had to look through quite a few diagrams to find that...

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post #3 of 4 Old 04-07-2013, 07:48 AM Thread Starter
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Thanks Noltz, I'm gonna try a 12v splice and see what happens. Don't know what else to do
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post #4 of 4 Old 04-08-2013, 09:51 AM
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1989 YJ Wrangler 
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You should s need to splice anything. Here is a link to the field service manual:
Here is a link for the FSM. Follow the adjustments on all the sensors.

When you read it you need to read with one of your probes refrence to ground on the battery or the chasis. If you have a meter and you dont see the 12volts then check at the relay. The manual should help you out.
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