My truck intermittently went into idle while driving and I could not figure out the problem to save my life. I checked the fuel filter and it looked fine. I was about to go after the HPOP and ICP but a buddy said he would check the fuel filter again. I went ahead and replaced it and it started right up and has been running great since. I turned out that a sludge that was the same color as the filter pleats had built up and I couldn't tell it was clogged by raising it up a little out of the canister. Hope this helps anyone else with the same issue.

 

Good to hear you got it fixed. I'm dealing with a 1211 now too. My fuel filter was not the problem though. I know it can be fuel related, so I'm putting electric fuel in and upgrading the hpop again. I hate that flippin 1211 code.

 

Learn something new everyday, it thought it was only a oil problem. The mule's fuel pressure stays at 70psi at WOT.

 

Edit - disregard; wrong thread.

 

I should note that I plugged the fuel restriction sensor because it was leaking, so i didn't know the filter was clogged. I think I'll be getting a new one.

 

Update:

Truck ran well for 5 days, no 1211, and then it started up again. I got a cheap fuel pressure gauge from Harbor Freight just to rule it out and it read 20 PSI at idle. I'm thinking this has to be it. Nope. Gauge was bad. So after spending $100 and a couple of hours on a new fuel pump, I'm right back where I started. I'm thinking this has to be oil. I don't want to throw parts in it anymore, so I might just take it in to have it diagnosed with a full scanner.

 

A lot of us have had 1211's, its tough one to solve. If it was me I would spent the money on a up graded HPOP before giving your money away to someone else. JMO