Hey everyone just wondering if anyone has experienced this or has any info on what could be happening. I had my engine light on for #6 solenoid failure so my mds was not working had no issues I fixed the solenoid now while driving the rpms will bounce up a few hundred and then drop back off consistently. If I drive with tow haul on it doesn't do this any ideas

 

Also Rpm Not consitent at specific speeds with msd on sometime it will be 1600 at 55 mph sometimes it will be 2000 at 55mph but with tow haul on it is always 1500 -1600 at 55 mph

 

When MSD kicks in disabling 4 of the cylinders, the RPM's will change a little. Not sure if it increases or decreases as I rarely look at the RPM's when mine changes. I've got the information center up top and I'm usually watching it to display "Fuel Saver". It does sound like it increases when it activates. I'll try to watch it next time to verify. Once MSD kicks off due to a hill or increased pressure on the gas pedal, the RPM will change again. More than likely this is what you are seeing. As for it not doing this in tow/haul mode, MSD is disabled in tow/haul mode.

 

Hey thanks for the reply my adorn is the 07 so I don't have the fuel saver indicator and the Rom to slightly raise when the mds kicks in but this is different this is raising 300-500 rpms then dropping back down consistently

 

Hey thanks for the reply. My adown is an 07 so I don't have the fuel saver indicator and this is different when my mds kicks in my rpms raise slightly but this is a surge at cruising speed usually 300-500 then drops back down. And I was using the tow haul as an example that when it ison and mds can't kick in it is fine

 

I'm running to town later today and I'll monitor the rpm's to see if I can duplicate your issue. If it is toggling up and down consistently with no change in terrain or throttle, I do find that odd. Although it could be due to other items drawing on the motor like A/C or Alternator fluctuations. However, I wouldn't think those would be noticeable at driving speeds.

 

Okay, during my drive today I only noticed a 100 rpm rise when MSD kicked in. Since you are seeing 300-500, I'd say this is not what you are dealing with. That being said, the only other thing that I could think of that would show up enough for you to see while driving like that is a possible clutch pack slipping. Hopefully I am wrong on that one because that's not going to be cheap to repair. I highly recommend you take it to your local dealer and show it to him. Might even have to take him for a test run to duplicate.

 

thanks a lot for looking into it for me, what was your rpms at cruising speed and how fast were you going, it is just weird because it is only when the mds engages that it surges like that. if i manually get my engine light to come on and the mds wont engage it doesnt do it, i run 1600 at 60 mph all day no surge or anything. i would just leave my engine light on and forget about it but my automatic start will not work and it is starting to get cold here and i enjoy getting into a warm vehicle.

 

If I remember correctly, at 65 mph it was running 1800 without MDS and 1900 with MDS. So what you are getting at 60 sounds about right.

 

I feel like the rpms are right but its when they bounce up and down when mds is active that is my concern