Air bubbles in Davco 382 - hard starting series 60

What about the first start after sitting when its cold

 

Did you ever replace the O-ring under the threaded hex nut, I had a hard start issue and I finally traced it to the O-ring under the hex nut, it gets dried up and shrinks, causing it to suck air.

 

Ok it still misses when its cold check for air in fuel

 

When it runs cold it misses an blue gray smoke an you smell the fuel also when its real cold if you pull the pipe exhaust pipe you will see it wet with fuel

 

You said they checked the relief valve on the back of the head. Tell them to just change it. I think they are like $15.

I've had guys call me with the same issues and it's always been the valve. Their wrench also told them that wasn't the problem but must be magic cause it fixed it. Do the cheap stuff first. Truck should pull better too after it's changed.

If it doesn't fix it you spent $15 on a part that needed changed anyway if you've never changed it.

 

they are like 200 bucks for a 14liter

 

I'm talking about the fuel pressure relief valve. Maybe what you are calling a check valve. I don't work on Detroit's but do know on a Columbia with a S60 it's on the back of the head and a pain to change.

On a cat they are around $25 and I know a friends was around $15 for his S60. Sounds like your loosing fuel pressure when sitting. That's one of the jobs of this valve. I can tell when mine is getting week from the fuel pressure gauge when driving before it becomes a hard start issue.