Cranks but no start, CEL light and reduced power light

[OMGTB]

Greetings,
I’m new to this so bear with me.... So, I’m working on my friends TB it’s a 2003 4.2 4x4. She was driving and stopped to talk to her friend and now it won’t start. Some Ahole shop said it was fuel pump and would be $800 to replace. I told her that’s BS and did the job for $100. Of course after replacing that, the fuel filter and the fuel regulator still nothin. Now I would have just plugged in my scanner to see WTF but when I did that, nothin. It only has 4 pins in it too. Looks like someone was geek’n on the wiring harness at some point.... I checked the fuses and found that fuse 13 (cigar) blows the fuse as soon as I try to put a new one in. Checked the fuse box under the rear seat and it’s all good. No blown fuses and connections and tight and clean. I got fuel up to the regulator for sure. I been so used to a OBD2 reader that I completely neglected the old school ways of check for spark,fuel, and compression. Gonna do all that tomorrow and see if the plugs are wet after cranking, see if they are sparking, and do compression test if I have both of those.... just seems so weird that it was running just fine and then after pulling over for 15 minutes, the damn thing won’t start. Sometimes it sounds like it wants to but doesn’t. Anyway, any info is good info. Unless your informing me of what an ass I am cuz I don’t know my ass from a hole in the ground with this forum shit. Your right, I don’t... but ya gotta start somewhere. Thanks to all for your help!

 

[Mooseman]

For the fuse blowing, disconnect and check each lighter plug. I had one of the two front ones that was shorted internally and damaged the wiring. Even after being disconnected, the power wire at the OBD port was shorted to ground so I had to cut it from the aux power circuit. Since I also made the aux power switched, I connected the OBD power wire to another battery source. That fuse blowing should not affect the engine running.

Good plan on checking the basics. Does the pump prime for a couple of seconds when you turn the key to RUN? When checking/tracing the wiring, use the schematics available in the downloadable manuals in my signature.

I do remember some fuel pump kits come with either an adapter or a pigtail when replacing the original pump due to a change in connector type so it could have already been replaced once before.

Edit: Just saw your title again and noted the REP light. This would mean an issue with the throttle control system. Once you get the OBD port working again, this will provide needed codes to diagnose.

 

[mrrsm]

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[gmcman]

Did she accidentally use E85 or diesel?

If the truck just quit then won't restart, I would leave the compression test for last.

Check the throttle body harness for any damage to the wires, or loose connection.