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Help => Vehicle Help => Topic started by: workgoats on June 19, 2013, 10:29:36 PM

Title: No fire to plugs
Post by: workgoats on June 19, 2013, 10:29:36 PM
1988 Cherokee, 4.0 engine, auto tranny.
Has 12 volts to module and coil.
Has 5 volts +/- to distributor
Has voltage fluctuation with cranking at distributor
coil has right resistance
pulled ECU (pain in rear) and replaced with another used one
no change in problem
Test instructions from internet (which never lies) says to check continuity between module and terminal C16 on the ECU.  I cannot figure out how to find terminal C16.
I'm to the point that I think it is a harness issue and plan to install a new wire directly from the ECU to the module if I can figure where to start.

We do not have the diagnostic plug for the jeep and I can't figure out how to read the codes from the check engine light until I get a new bulb installed.

I need this jeep running again so I can get my Caliber back from my daughter...
Title: Re: No fire to plugs
Post by: crazzywolfie on June 19, 2013, 10:45:07 PM
i think this might be what you are looking for
(https://lh4.googleusercontent.com/-G5qN237pgd8/UcJ2lPEt_xI/AAAAAAAAFNI/YtIaSgDLCcY/s669/88.jpg)
Title: Re: No fire to plugs
Post by: workgoats on June 19, 2013, 10:56:56 PM
Hey CW thanks a bunch.  That is what I have been looking for. 

I have found some input on a jeep forum saying that they are having the same problem but traced it to the crank position sensor.  I suspect I should check it before I do a bunch of hard stuff.
Title: Re: No fire to plugs
Post by: SixGun on June 19, 2013, 11:44:59 PM
As always, Mat you're the man.  :)
Title: Re: No fire to plugs
Post by: crazzywolfie on June 20, 2013, 12:12:35 AM
thanks. i try to help out the best i can when i can.
Title: Re: No fire to plugs
Post by: rjtx667 on June 20, 2013, 10:50:37 AM
I can send the mt2500 back down your way if needed?