Rough idle when cold.

[Solohopper]

Installed the IAT and it seemed to get better at first. But now it is doing it all the time. Warm or cold.

Gonna try the PCV and map next? This is sooo frustrating.

 

[Solohopper]

I am still having this problem. I have ran cleaners through the engine and fuel tank, I have ran premium fuel and I have ran synthetic oil with no luck. I guess my last resort is to actually pull the intake and replace the MDS sensors. I am able to clear the codes and the truck will run good for a while. but it seems to always come back.

This sucks.

 

[Redtruck-VA]

Clearing the codes should not affect the actual running of the truck. This has been IMO a long term issue with this truck since you said the #1 plugs have been changed by the previous owner but not all the plugs. The click you hear that seems to change the running condition is no doubt a key. I don't know MDS, but this seems related with the code you got. There is a cold to warm cycle event going from open loop to closed loop and this may be activating the MDS, but again I don't know that system. Good luck..

 

[Solohopper]

Its been a while since I have updated this thread. I have not been driving the truck as much this summer. I got a company truck so the dodge was out of sight out of mind.

But I finally took off the intake manifold to get a better look at what was going on. Here is what I found.

All of the ports that lead to the valves are oily except the first one on the drivers side. I have added a couple of pictures so you can see what I am looking at. I honestly have no clue of which way it should look. But the code i was getting before said I was having a problem with cylinder #1. Now I can see it is different than the others. The first picture is Cylinder #1. The second picture is #3. Any suggestions, tips, or ideas?

 

[HolyRamBatman]

That is either a really clean running cylinder or it is not working at all.

I thought you had quit the forum. Good to see you back.

 

[Solohopper]

That is either a really clean running cylinder or it is not working at all.

I thought you had quit the forum. Good to see you back.

Yea, the oily ones don't look right to me, but the dry one looks too clean. What are they supposed to look like? Is the oily ones signifying i have a seal problem perhaps?

 

[HolyRamBatman]

How many mile are on it?

 

[Solohopper]

how many mile are on it?

130k

 

[chedched]

Looks like a bad injector leaking fuel down. Just a hunch...

 

[hemihustlin]

I dont know how much an injector costs but at worst switch the 1 and 3 to see if the misfire follows before buying the part?
What i dont understand is the click before it starts working.

 

[Solohopper]

I had two different mechanics rule out the injector, coil and spark plug. I'm willing to switch them out at this point since it's all taken apart and easy to do. And especially since the motor has so many miles and I am not sure if and when it has ever been done. But I still want to know if the oily cylinders are suppose to be that way or if that is adding to my issues. I am going to start another thread that is more specific to what I found now that I pulled off the intake.

 

[hemihustlin]

Because what you are seeing on cyl 1 is the intake port has been washed by a continual leaking/dripping of gas. This will also give you your misfire on startup there is likely an accumulation of gas from sitting the night/the sticky injector reliving the pressure in the line. is it longer to crank before fireing in the morning? it is normal for the ports to be dirty/oily. The oily residue come from recirculated crankcase vapors.

 

[Solohopper]

Ok. That all makes sense. And that is what the pattern on the soot looks like in cylinder one. As if the injector is dripping into it. The truck fires normally whether its cold or warm. It has always fired right up.

 

[Solohopper]

I was told If it was an injector, it would always give me issues. Maybe that is the click I hear? The injector unsticking after warm up? That is why I only get it on warm up?

 

[Redtruck-VA]

I wish I could be more help, but the only click I hear around the engine is the TB blade closing finding it's zero step on startup. I've been testing my injector's recently with the engine off and cannot hear them click. I have no idea what sounds the MDS makes if any. But it is obvious something is washing that one port. I would do as suggested and swap the injector's to see if the problem moves with the injector. Good luck.

 

[Solohopper]

Back to the drawing board!!!

I pulled the intake, cleaned it all up, replace all the spark plugs, replaced injector #1, put it all back together and the SAME thing continues to happen. AND IT GOT WORSE!!!!

Not to mention I got a red lighting bolt and loss of power!!!

I have code p0301 still showing up.

UGH SO FRUSTRATING!!

So here is what happened once I started it. It ran rough right of the bat. Threw a low fuel pressure code which cleared itself after I shut it down and started it back up. Initially, it ran rough and it smoothed out and ran great. Good throttle response and plenty of power.

So i let it sit overnight and started it the next afternoon. SAME THING HAPPENED. It started just fine and ran rough just like always. it Immediately threw the P0301 code. and just like always, once it got warmed up, it ran just fine. (I could feel it running a lot smoother now after it warms up, so that was a plus.)

But then something worse happened. I was driving along and the red lightning bolt started flashing and i had no power. If I stepped on the accelerator, it would just bog down. Erratic idle when stopped and even shut off on me. Once it shut off and I started it back on. the lightning bolt was gone and I made it home. I had this lightning bolt pop up before but only for a couple of seconds and then it went away.

So I am back at square one with more problems.

HELP!!!!!

 

[Solohopper]

I took the truck to the dealer. They told me the cam and lifters are probably the cause of my problem. Can someone explain to me why that would cause the problem on cold starts and then run great later?

$3800 is the estimate. How difficult is it to replace the cam and lifters if they are needed? Something I should tackle myself? I am pretty mechanical but don't have any special tools.

 

[Redtruck-VA]

I took the truck to the dealer. They told me the cam and lifters are probably the cause of my problem. Can someone explain to me why that would cause the problem on cold starts and then run great later?

$3800 is the estimate. How difficult is it to replace the cam and lifters if they are needed? Something I should tackle myself? I am pretty mechanical but don't have any special tools.

That's the question the Service Writer needs to answer.

 

[Solohopper]

I spoke with the tech. He explained that once the truck warms up, the computer takes over and probably just shuts cylinder #1 off. The fuel may still be sent into that cylinder and that is why the cylinder is so clean compared to the others. During warm up, the computer is in a different mode and therefor the truck runs like crap.


I have been reading up on parts and the process of replacing the lifters and cam. Doesn't seem to be to difficult of a job. Parts alone from the dealer are about $900 which is what I had originally budgeted for. So It looks like I'll be tackling this project after the new year when I have more time on my hands.

Any experience or help that you guys can kick down would be much appreciated.

 

[Redtruck-VA]

I spoke with the tech. He explained that once the truck warms up, the computer takes over and probably just shuts cylinder #1 off. The fuel may still be sent into that cylinder and that is why the cylinder is so clean compared to the others. During warm up, the computer is in a different mode and therefor the truck runs like crap.


I have been reading up on parts and the process of replacing the lifters and cam. Doesn't seem to be to difficult of a job. Parts alone from the dealer are about $900 which is what I had originally budgeted for. So It looks like I'll be tackling this project after the new year when I have more time on my hands.

Any experience or help that you guys can kick down would be much appreciated.

I don't have experience with the 4.7, but with the hemi the PCM has two modes. When the engine is cold it runs in "open loop", meaning the fuel/ignition (AFR) is controlled by a internal table and the O2s has no input. When the engine reaches operating temp the mode changes to "close loop" with the O2s providing input (trim) to maintain the AFR to reflect this internal table that is constantly adapting to atmospheric and component changes (wear) within limits. If it is unable to adapt, then most often will generate a DTC. IMO, you do not have a cam/lifter problem.