Missing at idle. Been to 3 shops $4800 later...still no fix

[mtx1]

Ok guys and gals this is my first post here and i feel like im out of options. I know mopar man is the man so figured i would try here. I have spent over $4800 on this one problem and the Dodge dealer or local shops cannot figure out the problem. The truck has been like this for 3 years and im about to just part it out LOL. Here is the problem. The truck starts and runs fine when u first fire it up. It idles like it is supposed to until it gets to operating temps. Once it gets to normal temp it starts to "miss" at idle unless i keep the RPM at 1500 or higher. Once it misses the check engine light comes on and puts truck in limp mode. I can pull over, clear the codes with my OBDII programmer, start it back up and it will run fine for a few minutes and then the miss comes back. If i let the truck cool down and clear the codes, it runs normal until it gets up to temp again. If i let the truck cool down and dont clear the codes, the problem is there from a cold start. The code that comes up is 1690 cam position sensor does not agree with ecm.Ok so now on to what i have replaced :banghead:. First i replaced the VP44 with a brand new one from Gus at FBD. Same issue. So i replaced the cam position sensor. Then got 3 remanufactured ECMs and still had the same issue. I took it to Dodge and they replaced the VP44 with ANOTHER brand new one from Gus. Then a brand new ECM and Cam position sensor. After that it still had the same issue so they told me it was my Airdog not supplying enough fuel and i needed the "intank fuel pump" LOL. I was so sick of the stealership i paid them for everything and went to a local diesel shop and its been there since. I have a fuel pressure gauge and the thing never drops below 15 even when i had my Quadzilla on all the way. All this time the problem has been there, the chip has been off and i have left it off until the problem is fixed. So after taking to a local shop they told me it had to be something electrical and was possibly something with the wiring harness. So to save money i decided i would replace the engine wiring harness....well that didnt help at all and the problem is still the same as it was in the beginning. I have also replaced the Cam position sensor 3 times and even pulled a working one from a buddies truck and problem was still there.The truck is a 01 with 5 speed. I have Airdog 150 fuel pump, egt, boost and fuel p gauges, but everything else is stock. If anyone has ANY suggestion on what or where to bring this truck. I just want it running again and i have almost got half of what i paid for the truck just in trying to figure out this issue. Although i know i will have plenty extra parts if this thing ever gets back on the road. Thanks for any help guys

[jlwelding]

mtx1 you need to call me tomorrow around 10 central time. You have only spent 4800, try 9800 on the same symptoms you are describing.Mike and I narrowed it down to cracked piston or block, either way lots of bucks. I broke down and bought used motor and it's been smooth sailing ever sence. Oh, and lots of spare parts now

[mtx1]

Ok i tried to PM you but it said your inbox was full. I looked for your truck on youtube but couldnt seem to find it. Do you know what the title of the video is? Thanks for the help!

[Mopar1973Man]

I would highly suggest a compression test before doing anything else. One of JLWelding mistakes...

[mountaindan]

Think it may be a injector bad? Have you had them tested?

[jlwelding]

I looked and could not find it. Mike put it on you tube for me probably 3 years ago, I guess the stuff drops off after a while.

Mikes right on the compression test, the onlything about the test is do it cold then compare notes with eng hot,warm by the time you get into it, it should still be warm enough.

My truck would run and sound like the best eng you ever heard as long as you where idling in the drive way, go down the road 1/2 mile and the miss would start, just slight but you could tell it was there. Drive another 1/2 mile and it was a definite miss. My truck never went into limp mode, I didnt know it was even there.

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Ok i tried to PM you but it said your inbox was full. I looked for your truck on youtube but couldnt seem to find it. Do you know what the title of the video is? Thanks for the help!

I tried to empty with no luck, all I could do was delete 4

[mtx1]

Havent tested the injectors. Could an injector cause that code? I will go to the shop tomorrow and tell them to do a compression test cold and hot and see what they are. I will post results of them when i get em. On my truck the idle is the only issue. If i keep it above idle the code will never kick and it runs great. If i let it hit idle then the code kicks and goes into limp mode. When it hits limp mode the turbo takes forever to build boost but truck runs great all the way through RPM, its just at idle is where the miss is. If the code doesnt kick the truck runs like it did when i bought it, i just cant let it hit idle.

[Mopar1973Man]

As for the code here is the docs for it. http://articles.mopar1973man.com/2nd-generation-24v-dodge-cummins/59-obdii-error-codes/229-p1690-vp44-ckp-sensor-does-not-agree-with-ecm-ckp-sensor

[Wild and Free]

I would lean towards a wiring issue somewhere along the lines with all that has been done and from the description.My old 02 would run super when cold and once warmed up to operating temp would miss at idle and no load up to about 2k rpms, just a slight load even just the ac compessor running would smooth it out put it in gear and it would not miss.I swapped out my 150 hp aftermarket injectors with a different brand smaller 100 hp injectors and the miss disappeared.

[diesel4life]

Have you ever tried resetting your apps through out this whole ordeal? I know it doesnt explain the code that keeps popping up, but it sounds alot like when my friends apps went south and his truck actually never even tripped a code. If he started his truck it would run fine when cold. As soon as the truck started to warm up, something in the apps sensor would start acting up. It was like clock work, his temps would hit about 160 and it was like hitting a light switch night and day difference. Its a real outside chance, but you could always try the reset and see if it makes a difference it wont cost you anything. Also, Im sure theyve already checked, but make sure your batteries are in good condition and all your grounds are clean.

[mtx1]

Hey thanks for the replys. Sorry but i forgot to add, i have tried 3 different APPS. One i bought used and i had the same issue. Another i pulled from my buddies 02 and even though that didnt work, i bought a Timbos APPS and still have the issue after that one. Dodge had told me to replace the batteries so i had them do it when it was there a year ago. I am going to bring the truck back home next week and i will test the batteries. I am waiting for them to do a compression test first.

[JAG1]

I can only add a couple of speculative items to check;Bad tank vent? When the trucks runs long enough the tank could be getting a vacuum built up. With a clogged vent could it be eventually be sucking air into a marginally connected fuel line somewhere?Symptom of a bad tank vent is after a run, you slowly remove the fuel cap and you hear a small hiss/ sucking sound with the tank expanding back to a normal size.For that matter a fuel line that allows air to suck in after the fuel gets warmer and warming the fuel lines?:shrug:Could it be an injector that is not torqued down enough?Fuell filter o ring not tight?When the trucks running cold pull the radiator cap off and let it warm till she runs rough again and see if there are air bubbles coming out the top of the antifreeze just down inside the cap.Please let everyone know what you find it helps us all too.

[jlwelding]

Is it a steady miss or does it hit random?

[CUMMINSDIESELPWR]

just a thought, have you checked how clean the voltage coming out of the alternator is? (cold vs hot) also did you check the grounds?the common thing here is, it starts acting up when it gets to temp, seems to be the trigger?

[Mopar1973Man]

MTX1 do you happen to have a video camera by chance and send us a youtube of what the truck is doing? Might help use all to hear it at least.

[mtx1]

Ok went and picked up truck from the shop today and brought it to a friends with a shop. Did a compression test got between 320 - 390 on all 6. I pulled out the injectors and am going to have them tested in the morning. If one of them is not within spec...im just going to replace them. My friend more describes it as not a miss but like the truck is getting too much fuel, revs for a sec, and then back to normal idle when the extra fuel is gone. Like a leaking injector or something. Now here is where i got some where today. If we wire the pump with the "Hot wire Test" from BlueChipDiesel, the truck runs PERFECT. If we plug it back it the harness and restart...the problem is back. So with the engine running like crap, i can pull it in the shop, Hot wire test it, and it purrs like a kitten. Now this would rule out a mechanical issue....injectors, injection pump etc right? Anyone know where to go from here? I mean i have even changed the engine wiring harness on this truck... :banghead:Thanks guys for any advice! Much appreciated!!!

[CUMMINSDIESELPWR]

bad ground to vp? bad hot lead to vp? both point to a harness issue i think.

[mtx1]

Got injectors tested...they were trash. 4 were 30-40 bar off and 2 were 50 bars off. He said those 2 were just "peeing" so i ordered some new ones and hopefully this will cure the problem. I wont have it until after Christmas so i guess that will be my Christmas present . Will post what i come up with but if anyone has anything else to try please reply. Thanks guys Merry Christmas!

[SLEDWRECKER]

Not sure if the injectors have anything to do with the code your getting for cmp. There is also a possibility that your cam shaft retainer is getting ate up a little and letting the cam walk forward, or it could have possibly came loose, either way if the cam walks fwd and the sensor cant see the tone ring then it will be confused at best. I know its a long shot but you've covered all the obvious bases already, its also not an easy thing to check. Not even sure if you could check it w/o removing the front cover?

[mtx1]

Got injectors tested before i put them in and all were good to go. So Sunday we put them in. We checked the valves. Put my new powder coated valve cover on....and we got the same problem. We pulled the cables off alternator, cleared codes, same issue. Put a volt meter on my new Timbos APPS sensor to see if the APPS changed when it misses, it does not change at all unless i push the pedal. So...looks like the front cover is coming off. I ordered the gasket set today. If anyone has any other ideas...Please let me know! :banghead: Thanks guys!