Idle miss at stops

[cummins2k]

My truck ultimately runs great. It has good power. I recently replaced a crankshaft position sensor and noticed the plug will need to be replaced also. However replacing the sensor only, the check engine light has not illuminated again.However recently I have started to get a miss at idle after coming to a stop. Very slight, but noticeable. You can feel it in the truck. Not similar to the hard miss the crank shaft position sensor caused. The weird thing is my AirDog 150 has also started dropping pressure pretty bad. When new it was putting out 17psi nearly constantly, about a year later it was at 15psi. Then it kept dropping, much quicker after that. Now it is at 11-12psi idle. Though it still holds over 10psi WOT. I do have the typical draw straw issues at 1/4 tank.I purchased a new filter tonight (NAPA) and plan to install it tomorrow. If the pressure does not increase a significant amount I will add some washers to increase the pressure like I have seen done on here.It seems as though the AirDog is drawing air more often than it used to. At a 1/2 tank I can draw air. I did replace the sending unit recently so I am fairly sure it is not that. Besides I can run the truck to nearly empty and as long as I don't make a quick stop it is fine.You can hear the difference in the pump noise when it draws air. It is fairly significant. I am planning on installing a draw straw in the basket to remedy the 1/4 tank issue.It is just odd to me that this miss only occurs at stop lights regardless of the tank level. Once it has idled for a bit at the light it clears out. It never happens when the engine is cold it seems. Only when warmed up and after a stop. No elevated smoke levels at all.The truck is slightly harder to start in the cold lately. I plan to replace the battery cables and probably start looking at replacement batteries...these Walmart batteries didn't last nearly as long as the Duralast I had before. The truck also on occasion cranks for a long time when parked facing down hill.Any ideas?

[JLandry]

Are you sure your fuel pressure gauge is accurate? It's always a good idea to get a "second opinion" by checking the fuel pressure using a different (accurate) test gauge.For that miss, it couldn't hurt to disconnect and reconnect the VP44 and ECM connectors to clean the contacts.Good luck,John L.Sent from my iPad using Tapatalk HD

[Mopar1973Man]

Ok... Do you have the new quick connect AirDog? Did you trim the drawstraw during installation? If so how much did you trim off (gap to bottom of tank)? Did you cut the drawstraw at a angle or notch it? As for drawstraw I don't have such issues... I can run to the low fuel light (1/8 tank without much problems). http://articles.mopar1973man.com/2nd-generation-24v-dodge-cummins/25-fuel-system/30-how-to-install-a-airdog-150-fuel-system

[cummins2k]

Are you sure your fuel pressure gauge is accurate? It's always a good idea to get a "second opinion" by checking the fuel pressure using a different (accurate) test gauge.

For that miss, it couldn't hurt to disconnect and reconnect the VP44 and ECM connectors to clean the contacts.

The fuel pressure reading is provided by the Edge Attitude monitor and as of now I have no reason to not believe it is accurate. As for the contacts it wasn't long ago I cleaned them all out with electronics cleaner.

Ok...

Do you have the new quick connect AirDog?

Did you trim the drawstraw during installation? If so how much did you trim off (gap to bottom of tank)?

Did you cut the drawstraw at a angle or notch it?

As for drawstraw I don't have such issues... I can run to the low fuel light (1/8 tank without much problems).

I have one of the original AirDog 150's. It was purchased quite a while ago. I did trim the straw per the instructions. Honestly cant remember much of it. The truck will continue to run to the fuel light. However stopping quickly will cause it to draw air. The truck continues to run but you can audibly hear the pump noise change and the pressure will momentarily drop.

I did replace the filter today. No change in fuel pressure. Was sitting at 13psi when I started it with the new filter. Nothing I hadn't seen with the old filter.

[Mopar1973Man]

Check the check ball and see if the ball is jamed in the coils of the spring. If so just slightly crush the last coil enough so the ball can't wedge it way down into the coils again. Do this first before adding shims. You might find a huge increase...

[jlwelding]

The miss you are talking about sounds like the exact same miss I had in mine. I had people here logging off when they saw me posting:lmao:My eng. would set and idle great all day long as long as you didnt drive down the road 1/8 of a mile, then it would start with a slight miss.I replaced everything under the hood, some things three times, like the inj. pump I even put a rebuilt head:spend:two wiring harness, three ecm's I finally put a used eng. in and it's been fine since.I would try pulling the injectors and clean them, also put new crossover tubes in.

[dripley]

The miss you are talking about sounds like the exact same miss I had in mine. I had people here logging off when they saw me posting:lmao: My eng. would set and idle great all day long as long as you didnt drive down the road 1/8 of a mile, then it would start with a slight miss. I replaced everything under the hood, some things three times, like the inj. pump I even put a rebuilt head:spend:two wiring harness, three ecm's I finally put a used eng. in and it's been fine since. I would try pulling the injectors and clean them, also put new crossover tubes in.

JL, I joined up here in the middle of that and never got smart enough to run away. It was a saga to say the least.