Possible resolution for P0340 and P1391 codes
My jeep screwed up on me the other day right before a big trip. I got P0340 and P1391 codes. P0340 is a code that deals with the Crankshaft position sensor and and/or the Camshaft position sensor. Which, in short, if the computer doesnt get a reading from these two sensors it cuts the fuel delivery. I replaced the crankshaft pos. sensor before my trip and i couldnt get the camshaft sensor so i just went on my trip. Jeep ran fine till i stopped to get gas and turned 'er off. It wouldnt start back up. If i did get it to start up it wouldnt accept any amount of fuel.
Ended up ordering the cam position sensor, put it on the next day and it would start up every other time or so but wouldnt stay idled after any amount of throttle. Had it towed to a nearby jeep dealership and it ended up being the "oil pump driveshaft gear" (the shaft the cam sensor sits on with distributorless jeeps.) They replaced it and it runs 10x better now.
Just thought i would share my experience with you all. And it was $302 parts/labor at the dealership.
Crank sensor $115 from federated auto
Cam sensor $55 from advance auto
'02 TJ Sport - 3.5" RE Springs/Mono-tubes; BFG A/T 33x12.50x15 on ProComp Black Steelies; JKS: BPE's, 1.25" BL, shock conversion, front Adj. TB's, quick discos, Extended Brake lines; FT 3-link rear; JCR 1-ton Steering; Warn 6" Flares; Olympic Slider Bumpers; OME SS; Taurus Electric Fan; 4.88 Gears; D30/D44 Detroit True-Trac Front/Rear;