Recent content by Fantabox

Everything is still working as intended, and have not had any issues since the last update. Thank you again, to everyone, for offering thoughts and opinions.

Since the fuel system was an open-loop, and only clean fuel was being used to flush the system, the fuel filter was fine. The old fuel pump clogged up and was unable to even prime the fuel system, and I suspect none of the old fuel was even able to exit the tank.

FINAL FOLLOWUP.....HOPEFULLY: After reading some feedback I was able to discern that the black substance was really old fuel. The old fuel had essentially congealed in the fuel lines and fuel rail, which was not checked prior to the first fuel pump swap. Thanks to everyone that offered their...

I don't have a perfect answer, or the "ah-ha" moment, with this issue, but my best guess is the bad injector(s) were allowing oil to enter the fuel rail, and then into the fuel return line. I am attaching JPG photos to this post.

UPDATE: POSSIBLY SOLVED I didn't want to leave everyone hanging without a followup, so here it is (with photos). Today I pulled the old fuel injectors, dropped the tank, and found the issue (or I hope I did). Two of the injectors for cylinders 3 & 4 (rear two) had oil inside the injectors, as...

I plan on working on this issue starting on Wednesday. The strategy will be to get the new pump hooked up, but inside a clean bucket with new fuel, and the return line will dispense into another clean bucket. That way I know new fuel is going into the lines, and I can separate any tainted fuel...

The Jeep is always in our garage/ shop and I am the only person out there. This entire issue is perplexing, and I am not 100% certain what caused the issue.

The tank was fully cleaned out nearly two weeks before being re-installed. It was bone dry.

Thank you for the replies thus far. I will keep this post updated as I venture out into the unknown with this issue. NEVER seen this, even when I was a mechanic, and I was hoping someone had a known fix.

I thought about this too, but it seemed TOO FAR STRETCHED even for my imagination. Glad someone else is pondering these types of possibilities.

I was tossing around some fairly irregular theories in my head. Including a vacuum line from the differential, EGR port, injector was allowing oil bypass into the fuel return line, etc etc etc. Nothing makes sense on this, and my only course of action is to clean out the tank...again...and see...

I was hoping the issue would have been caused by me, but I never removed any vacuum lines, I am the only key-holder, used new fuel from a new container, and when it was running there was zero blue smoke from the tail. I'm at a complete loss on this issue, and have NEVER experienced this ever.

Hello Everyone, My name is Patrick. I live in Snohomish, Washington (pronounced Snow-Home-Ish). I have owned this Jeep before I even had a license. My grandfather bought it new. The Basics: 1993 YJ 2.5L with 95K miles My Actions Prior To The Issue: - Changed the oil & filter - Cleaned the...