Hello everyone. Needing some direction. I own a small 1 man auto repair shop here in Tennessee. I have a farmer with a 2001 F350 SuperDuty with a 7.3 broke down at his farm a few weeks ago. Asked me to come look at it. No start issue. I use the Matco Determinator in my shop, so I take it with me for starters,after running diagnostics I come up with p0340, p0344,& p1670. After googling these codes I make the determination idm is bad. Farmer agrees to let me try one, install a new BorgWarner unit from O'Reillys, and bam truck fires up. I reinstall inner liner clear codes and go about my way. Few days go by and farmer shows up again, truck run a few miles around farm,spits sputters, and dies again. Go run my checks and same thing. Farmer told me in nthe beginning he had CPS changed per the recall. I had idm replaced under warranty truck fires back up, so this time I drive it , and get bout 2 miles down road truck dies. Had to tow strap back to shop. Got a new cps from ford replaced truck fires up. Farmer takes truck drives for bout a week guess what truck gets towed back. 3 codes are back, along with a few others related to low voltage. This time I replaced idm for a 3rd time, truck fires up. Today I let it idle for 3 hours in lot, decided t test drive, got less than a mile down road, truck shudders chi engine light comes on and it wants to die but keeps running. I am able to get turned around but it dies before I can get back home. Run codes and get same 3. So can someone point me in the right direction? Thanks

 

Check to see if the fuel tank is venting as fuel is consumed. You might have something as simple as a clogged canister vent system. Next time it sputters, remove the fuel cap and see what happens.