87 Ignition Power Module Wierd No Start

87 4.0 AW4 NP231 D30/D44 108k

Hi Guys,

So today I change my oil, put some rags around the oil filter to catch the drips. Finish and she cranks, but no start.

I went back to the IPM, and checked the two connectors. I had previously cleaned them per Cruiser54 about two weeks ago. I jiggled the
wires and she restarted fine. Jiggled a wire and it shut down like a light switch was turned off.

Looking down on the module and connectors from the passenger side,
the right hand connector has 3 wires. The right wire(green/white) runs
about 4 inches to a spliced connector and a white wire comes out. I have had the jeep since 87 so this must be factory. According to my fuel injection manual schematic, this wire runs to the tach.

When the jeep was running again, I wiggled the splice(green white) and it shut down immediately. I tightened the crimps, and all seems ok.

Question: Why would this one faulty splice to the tach shut the engine off. Am I missing something!

Thank you!

Greg

You're not missing anything. That splice goes off to the diagnostic connector # D1-1.

See what happens. Sure the wiggling of that splice wasn't doing anything with the black ground wire coincidentally

Thanks cruiser, will check the ohm reading on the black ground wire.