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Fuel Injection Problems

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Old 07-18-2017, 11:53 PM
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Hcl
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Default Fuel Injection Problems

Hello All,

I am having trouble with my 99 Cherokee sport, the check engine light came on (codes P0201 & P0301) and was running rough after taking it up a trail. I later found that it was a broken wire to fuel injector #1. see previous post:https://www.cherokeeforum.com/f2/che...e-help-237333/

I tried wiring on a new connector but it didn't fix the problem. I rented a set of noid lights and I am not getting a pulse on the that injector connector. I tested the connector with a multimeter and got 12-13 volts. All other connectors got a pulse but did not read voltage (but i don't know if I just couldn't get solid contact between the probes and the connector). Should the connectors read voltage when running? Any thoughts?

Cheers!
Old 07-19-2017, 05:18 PM
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Hcl
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Could it be the computer? I'm just puzzled because the connector was clearly broken and it's been fixed and has voltage.
Old 07-24-2017, 08:20 PM
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I still have not been able to resolve this issue. But after doing some test with a test light it appears that the problem is in the PCM. Is it possible that the circuit connection shorted out the PCM or is there a way to reset that now that the circuit has been fixed?
Old 07-24-2017, 09:23 PM
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If the wires were broken, and shorted together, it's possible that it damaged the part of the PCM circuitry the controls that injector. If that is what happened, then a new PCM is the only cure.
Old 07-26-2017, 06:31 AM
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Is there a ground on that plug?
Old 07-26-2017, 08:14 AM
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The ground for the plug goes through the PCM. I unplugged the connector at the PCM and used a test light in the connector. The light worked so I'm thinking all the wiring up to the PCM is fine.
Old 07-26-2017, 09:41 AM
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theres a great video on this in another thread. ill try to get a link.
Old 07-26-2017, 09:47 AM
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check this.
Old 08-18-2017, 12:38 PM
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Follow up:
I got the new computer and changed it out. The new one worked fine, fixed my misfiring cylinder, but only for one day...

The following day my checked engine light came on again. I stopped and had the code read. P0443: EVAP control valve circuit malfunction. No other codes.

Did they send me a poorly refurbished computer that only lasted one day or is it possible that the code is accurate and worth looking into? Also my blinkers stopped working around the same time. Any thoughts or input?

Thanks!

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