2014 ram idle cam swap issues

[[email protected]]

hi, I have a 2014 ram with the 5.7 hemi and it had cam and lifter failure. I replaced cam with mds cam replacement with non mds lifters. I have mds turned off. after replacing it I have been fighting a cylinder 6 misfire only code is p0306. It idled rough and would die when coming to a stop. I have checked ,swapped and replaced spark plugs, coils, injectors and have replaced the pcm and vvt and cam sensor the map sensor and throttle body as well. I checked for vaccum leaks and non were found. compression test was good it was 180 along with the rest of the cylinders on that bank. Pushrods were not bent and were fully seated in the lifer and no bent valves or broken springs. i took it back apart to check lifter and they are in good shape not collapsed and looks like the have oil going to them along with the cam that looks good as well. I dont know what else to check and any ideas on where to look next would be a big help.

[malikib]

You can’t have mds camshaft with non mds lifters , you need to change the camshaft or the car will never run right

[[email protected]]

Ok, my thought processes was that if the truck had mds lifters and cam but mds turned off then it wouldn't matter if non mds lifters on mds cam because the lifters would still still roll over the cam as if mds was turned off. So your saying regardless if mds is off it has to be non mds camshaft with non mds lifters?

[PurpleRam]

You can?t have mds camshaft with non mds lifters , you need to change the camshaft or the car will never run right

Yes you can, It?s not optimal, the mds lobes are shorter duration, by 4* @.050, if it was the mds cam causing the issue it misfire on all 4 mds cylinders.

Nick I don’t have an answer except, check wiring , if it is throwing the code after swapping in different coil packs and injectors, and lifters are good, process of elimination, did you swap lifters with another cylinder? Last thing to test is valve springs on #6,I know you said you?re working on a 14, but 2011-2013 had some spring issues, a lot of springs installed that wouldn?t meet QC requirements made in to production??.

Ran all 6 of my old company’s 2013 trucks that way from 2016 to 2019, 70k mile per truck, never a code throw

[[email protected]]

I did swap lifters with cylinder 8 and problem p0306 is still there. I visually inspected the springs and non are broken. I checked wiring for coil and injector and I couldn't find any issues. No broken or shorted wires. Has continuity through the wires. I'm really just stumped.

[PurpleRam]

If it were me , I would Try bringing the idle rpm’s up 150-200 over stock , give it 10* of spark in the idle area of the pt table, clear the code, let it idle for a while, checking ve and fuel trims, add/subtract if needed.

If the ecu was crapping out, I would think there would be more codes being thrown

[PurpleRam]

I’m assuming it does this with NN on or off?

[[email protected]]

Yes it doesn't matter if nn is on or off. I tried raising rpm to 750 and it will misfire less than it would around 600 but would still misfire and when coming to a stop it would still die. Then I raised idle to 800 and wouldn't misfire at all but when coming to a stop it would start to misfire on multiple cylinders but more misfire counts on 6 and would die. Mind you with the rpm changed to 750 and 800 it still felt like a misfire and idle rough but the scan tool didn't pickup any misfire counts with those idle rpms being high. If it was fuel pump of maf sensor wouldn't it effect more than one cylinder at idle?

[PurpleRam]

Yes it doesn't matter if nn is on or off. I tried raising rpm to 750 and it will misfire less than it would around 600 but would still misfire and when coming to a stop it would still die. Then I raised idle to 800 and wouldn't misfire at all but when coming to a stop it would start to misfire on multiple cylinders but more misfire counts on 6 and would die. Mind you with the rpm changed to 750 and 800 it still felt like a misfire and idle rough but the scan tool didn't pickup any misfire counts with those idle rpms being high. If it was fuel pump of maf sensor wouldn't it effect more than one cylinder at idle?

you would think so(MAF and Fuel pump) ,

Timing being off a tooth should affect every cylinder, so I doubt it's that.......An oddball thought is tone wheel might of been damaged , but I doubt it..., have you tried a cam sensor ? , I would think that would also affect all 8.

[[email protected]]

I did try cam sensor and that didn't help. The thing is it doesn't misfire or have any issues while drive or under load its just at idle and coming to a stop. I cleaned out the fuel rail to make sure there wasn't a blockage and took air filter off to make sure it wasn't being restricted air flow wise but still does it. The only things I have replaced yet is the crank sensor(doubt it's that but worth a try) and maf. Other than that this while thing just doesn't at up because before cam and lifters failure it was running fine no indication of any issues but after the new cam lifters I have these issues with a different bank. And timing was triple checked and all the marks lined up after the tensioner was put on.

[LilSick]

The /misfire for no reason wiring harnesses/ did not come around until later, correct?

[Spray-Cam Hell-Ram]

check the gap of the spark plug for number 6

[Spray-Cam Hell-Ram]

And I see where you said you checked the wiring for the number 6 coil and injector, ect...But have you checked to see if the coil pack for number 6, itself, has gone bad?

[[email protected]]

The gap on the plugs are correct and I checked the coil itself and it ohm checked it and the coil was fine and I even swapped coils to a different cylinder and the misfire stayed on cylinder 6. Even if mds is turned off could it be a broken wire or a shorted wire on mds harness that could cause the misfire?

[Spray-Cam Hell-Ram]

From what I can tell, the mds harness is only responsible for oil control of the mds cylinders. I can't see where a short in the mds harness would cause a miss in a single cylinder or really any cylinder for that matter. Purple Ram will probably know for sure, but I feel somewhat certain that the mds harness wouldn't be the cause here.

[Spray-Cam Hell-Ram]

Being that there is no miss while under load and this only happens at idle.... it's really hard to believe that the issue here would be mechanical. How is it exactly that you know that it only misfires at idle and never underload?

[Spray-Cam Hell-Ram]

Do you have headers installed? Wondering if it's possible that something got lodged in your number 6 intake or exhaust port? I had one of the little dowel pins that you set your head on when installing break off, causing a bunch of problems on cylinder #1 once before...

[[email protected]]

I have a scan tool that can monitor misfire counts for all 8 cylinders and it acts like a dead miss just keeps going up and then I drove it and the misfire count stops. But for the mds harness doesn't the computer disable spark and fuel to the cylinder when mds is in use? I know it makes no sense since it's disabled. And I do have headers but the valves are seated all the way and they are not bent. When I took the heads off to swap lifters to see if it was lifters I pulled the springs off to see if there was any damage or stuck material in the valves and its all good.

[Spray-Cam Hell-Ram]

It does cut fuel and spark, but I would think this would ultimately be done through the main harness at the injector and coil pack connectors. Have you tried replacing your oil control valve? And when you installed the new camshaft and were hooking everything back up to the engine harness, did you remove the mds solenoids and replace them with mds plugs? And if you did plug up the holes where the mds solenoids used to be, you should have been left with your mds harness with no solenoids left to plug that mds harness into... and if so, did make sure to plug up, the oil control valve? Being that it's at the "end of the line" so-to-speak of the mds harness and the power supply and everything runs through that harness so even though the solenoid portion of the harness just lays there unused, the last connector of that harness still needs to be plugged up to the OCV. Im not trying to insult your intelligence or anything here.... Just trying to think of any other possibilities that haven't yet been mentioned.

[[email protected]]

Your all good man I'm just trying to fix this and get it running lol. But yes the mds solenoids are replaced with plugs but I left the solenoids plugged in so the connectors wouldn't get corroded. And isn't the solenoid at the end of the mds harness that goes to the back of cam phaser/gear the vvt solenoid ? And that solenoid was replaced on the end of the mds harness.