Hello all, I'm new to the forum and in need of serious help. I have a 92 explorer in which i love dearly. She has 350,000 miles on her original engine and had a tranny put in her in 96. This truck has been nothing short of amazing, only has had minor electrical problems.
Today, while driving it, it began to act weird. The engine kept reving up and down and the oil light came on (changed the oil two days ago). Then it shut off.
I replaced the fuel filter, but that didn't help.
Rab the computer and it said the octane pin was open.
What is this?? I can't find any info online at all!
Any help would be so greatly appreciated!!

 

KOEO 341 usually indicates an open in the octane adjust pin circuit (pin 44 at the PCM according to my wiring diagram). I believe the shorting bar is located under the hood, passenger side, near the self-test connector. Some service procedures will remove the bar, and there should be a sticker indicating if this has been done according to procedure. If there's a loose connection in the circuit, it would cause your timing to be a little erratic.

 

Thank you mrshorty!
We found the adjust pin and it had been removed, so we tried to jump it and the truck still wouldn't turn on.
We then checked the spark plugs and they were fine. The truck tries to start every now and then, so we've ruled out starter/alternator.
It also seems to be getting fuel.
The truck simply wont start at this point, therefor we can't run a running check on the computer.
Since we are at a complete loss, we are having it towed to a mechanic today. This will be a first, we have done all work ever needed to it. This is actually the first time I have ever taken any car to a mechanic, my dad worked as a mechanic for years and is a mechinist at the railroad. Anyway, I am realy anxious, so wish us luck and thanks again!

 

Maybe timing chain/belt?

 

Are you getting spark at the plugs? Also, you can pull codes with the engine off.

 

Thanks for all your suggestions. The truck is still at the mechanics and they weren't able to get to it today.
In the meantime.. On the news last night they announced that there has been an outbreak of bad gas in the area, and guess what, the tank had just been filled. My dad thought it was a fuel problem, hence the changing of the fuel filter.
Anyway the mechanics wont let me come up there and drain the gas and refuel my truck in their parking lot and since it wont start, I'm kinda stuck. So lame!!
Thanks again for all of your help, I'll keep ya'll posted.