Well it just came back again, but took a lot longer this time. At least it's ruled out now. Time to check more of those things...

 

could have been multiple problems, and now youve solved one... but i suspect the CKP was related. i wouldnt rule out wiring or ecu, or some sort of connection issue somewhere along the line....

keep us posted!

 

Some codes are two drive cycles or more before they pop back up.

 

This one has always popped up immediately. I could clear it, drive around the block, and it's back. However, it might have something to do with test driving from a cold start. Even though it does seem smoother, maybe that's why it took longer this time. I cleared it after the truck was already warmed up, then drove around for half an hour never seeing a code and so declared it a success. So maybe it's misfiring more when it's cold.

 

What was the code?

What do the signals from the IAT and the coolant temp sensor show?

 

P1313 P1314. Same buggers.

Temps look normal to me. Engine is ambient when cold and warms up to thermostat temp (180) and hovers around there. Intake is ambient and warms up as the engine way warms.

 

So the ECU thinks that more than 15% of your combustion events result in a misfire, but you feel it is smooth running.

 

Eric, you said earlier you were losing FP... did you measure the loss rate?

There are three questions for you here sir...... What is your fuel pressure at the rail when engine is idling, then when off but key in pos II (pump on), and how long does it take to lose pressure...down to 20 or 10 lbs once the pump is off?

how old is the pump assembly? (that makes four questions)

 

i'm following this pretty closely as i've had a 1316 that keeps popping up even after the rebuild so i can rule out sticking exhaust valves.. Not the same code persay but still misfire related

 

Finished test with real tester, instead of tire gauge.

Ignition on, engine off: 37 PSI
Idle: 31.5 PSI
Engine off, key out: Slowly raised to 36 PSI over two minutes?, then dropped to 20 PSI after 25 minutes, then dropped to 10 PSI after 25 minutes more.