Zadouw

Just wanted to make a quick comment to let you guys know I haven't ghosted. The weather has kinda gone to crap and I don't have a lot of available daylight during the week, but I will be hitting a bunch of this stuff this weekend and update you guys with the progress. Thank you to all who have chimed in!

No change with fuel added into the throttle body :/

Ok, how much fuel would you say to put in? I can give it a shot.

I put a fuel guage on the schrader valve on the rail and was getting 40psi when cranking and after it died, seemed to be holding the pressure fairly well. The ignition cylinder was drilled out (the lot I got it from got it at auction from I believe a mechanics lean) could that have caused something to be out of wack? I tried holding it in the start position to see if it was a problem with the run circuit to no avail. But I'll didn't see anything about how to check the alignment of it at that link, but I'll do some searching. The ground clean up stuff seems interesting and I will have to give that a go. Would be good to do even if it's not the issue. I've been trying to eagle eye any connections and wiring, especially anything tied to ignition/fuel. But I honestly don't know what all redundancies are built into it that may be causing it to shut its self off. Throttle position sensor may be my next goto though sense 0/10/20/50/100% throttle doesn't seem to make any difference at all with the rpms it fires off at.

I have not. Wouldn't that just potentially flood it? Most of my mechanical experience is with HD diesel engines, and some fairly new gas engines (like 2000+ at the earliest)

Yes, the second part of my first response to this was supposed to say 12v directly to the resistor and the wire directly after it to give the pump direct power. I miss typed it, sorry about that. I also have the resistor bypassed with a paperclip at the moment just to make sure.

Brand new battery, but I did check that too. Voltage isn't dipping below about 11, maybe 10.5 volts. Never worked on a renix system, but I've never tun into that issue unless it drops below 9 while cranking. But good thought!

Relay is the one that came withe the truck(generic 5 pin relay). But I did jump it from the 30 pin straight to the power pin for the pump and tried to start it with the jumper in place and the pump running full bore, no change.

Also, not exactly scientific, but I used the pump to drain the old gas out. (Put bucket under the fuel line with old fuel filter dangling down and jumped the relay to pump It all out) it seemed to be making good flow. But again, not exactly a scientific process. 😅

Yeah, I did it 2 ways. I jumped the relay, then I replaced the relay and put power directly to the power wire coming off the relay to the pump its self.

No change at all with gas pedal to the floor

Like the key was turned off, if I jold it in the start position it will start and die repeatedly with the starter engaged.

All checked out good, D1_6 goes hot only when fuel pump is priming with key in ON position

First time post, I have scoured most of the site and tried anything related I could find. 1989 mj, 4.0, 4wd, automatic. I got the rig recently as a project swap from a random car lot. They were able to get it to run momentarily using ether to show that the engine its self was in decent shape. 👌. Now that I have it home it will fire up perfectly fine, but then immediately shut its self off like the key was turned off. Things I have done so far: Replaced distributor cap and rotor. Replaced all plugs and wires (verified gap on new plugs). Replaced/repaired any vacuum hoses I could find. Replaced crank position sensor. Replaced fuel filter. Verified power to the fuel pump. Verified 40 psi in fuel rail. Jumped the balast resistor. I even tried starting it with the pump wired straight to power constant (via the relay and at the resistor out). I am at a loss for what could be preventing it from staying running at this point. I can't seem to check any codes as the "maintenance" light does not illuminate (swapped in a known good bulb). Any advice, or ideas would be greatly appreciated. Thanks in advance!