99 Ram 2500 4x4 auto 5.9 24V  bought it with 89K on it now has 116K.  The Issue I have is intermittently when it starts it has a ideal lope for about 5 to 10 seconds then ideals normally which around 740 -750 rpm... occasionally 800 rpm...  The problem is/was magnified when I installed 75HP injectors... bigger lope like it had a big cam in or something... but again it would ideal normal after 5-10 seconds on it own or if gave it some pedal... it would also like to stall when putting it in reverse with the 75hp injectors sometimes... the problem is only at start up truck runs fine other then that... I put the stock injectors back in and still does it just at a smaller lope...(problem has not worsened with time)  I really would like to run the 75hp injectors but the loping is like a pulling truck and the stalling is annoying... any ideas?

thx guys

So I'm running 100hp injectors now. This issue started with my RV275 injectors changed them out to 75hp still an issue then went to DAP 100hp sticks with no change. The one unique thing I have noticed is that if I let the truck run for a few seconds then put it into gear everything is fine. If I jump in fire it up and throw it into reverse real quick it will lurch or lope. Fuel pressure always monitored from mechanical gauge readings haven't changed much from 17 psi at idle to 15.5 wot.

So this doesn't matter of the engine temp or runtime, hot or cold outside. I can make this happen on command anytime I start my truck.

Sounds like mine... I can do the same thing clears up on it own or if I throttle past idel a little bit it will be fine.  I think my truck had a remanufactured VP... Is your original or remanufactured? did you watch my video is you like that?

It has to be fuel related right? So does it take a minute for fuel to pressurize the lines?  

I'm on my 3rd VP in 200k miles and yeah mine acts the same as yours does in the videos.

What is it? I got the Timbo APPS all fine tuned...same deal. Cold start, put it in gear (drive or reverse) and she nearly stalls out, once down the road and warmed the rpms fluctuate when shifting put not close to stalling.

Sluggish   governor  when cold?  *meaning  engine  still ambient*    I had  more than one  mechanical injected tractors that would  burp burp burp  at idle,  worse  when   rolling.  (loose cab mounts and solid rod  throttle control)  but  got  better when warmed..        All the posters  in this thread  with  killed, or near  stalled engines   when shifting to R  makes me wonder if the  2 maybe  connected..

VP's are  electronic governed right?

 

I wonder if  next time you EXPECT it to lope at start up,    open the hood,  and  have someone  grab the throttle linkage and  keep it  tight against the  idle stop... as you  fire it up.    You may have   a little  wiggling  in the engine mounts  and  throwing it in reverse REALLY torques it over and   kills it??? hmmmm,  a  sheathed pull cable  usually doesn't  cause these kind of  problems..  solid one sure would!

 

Why  would  reverse  'hit' the engine  so much harder than  D?  not modulated as much??

Rancherman...The throttle is all electronic controlled, stop and all.

Chris

Rancherman...The throttle is all electronic controlled, stop and all.

Chris

I would've sworn there was a  pull cable to the  VP...  what the heck  did I  remove and replace  when I changed out my vp??

All I was  trying to say was..  sometimes  when a  engine surges,  it'll  'pull'  against the throttle.  which either  slows it down or speed it up..  just a tad.  once it  gets to 'bouncing'    it's  hard to stop...    but as  I said,  a   sheathed  cable  doesn't  respond  like a  solid rod.. because it  moves  with the engine..  

The cable goes to an electronic sensor thats mounted abouve the VP44. From there its all electric.

If the motor mounts were toast I don't think the cable would move enough to change anything.

Its a pretty sturdy setup .

Chris

Thought so!  ha~ 

   I agree too,  since the  cable  moves  'with' the engine.

  I was just throwing out  'stupid dumb' type  things  I've  discovered over the years..  Stuff that  at first glance  would never be  an issue..    I've learned  to never assume the worst..  until  all else has been  eliminated!

 

Ya know,   immediately after startup...   the  voltage  in the  system  has to be  haywire..   the  battery just got done  spinning the engine over,  the alternator  is  just  coming on-line..  and   maybe   the grid heaters  are  still  going  nuts  (hopefully not this time of year)...  It's amazing  the  electronically controlled    IP  works  at all!

I'm on my 3rd VP in 200k miles and yeah mine acts the same as yours does in the videos.

Did the idle loping stop after installing a new VP?

 

what injuector are you running?

I know you did the APPS sensor voltage. Just remember one thing idle as long as the OE APPS sensor is BELOW the tag voltage then the ECM will IGNORE the APPS voltage and use internal ECM software for Idling.

With the cable subject brought up, sometimes, they fray internally & can hang up. I doubt that is the issue, but just an idea.

 

Ed

I know you did the APPS sensor voltage. Just remember one thing idle as long as the OE APPS sensor is BELOW the tag voltage then the ECM will IGNORE the APPS voltage and use internal ECM software for Idling.

It's an OE and I am below the tag voltage... So the ECM should be commanding the correct idle info to the VP... so I am wondering that the 750rpm and not 800rpm that I should have along with the lope are somehow related.... is it possible that the VP is not processing the the idle commands / rpm properly because some component in the VP is breaking down? 

I know you did the APPS sensor voltage. Just remember one thing idle as long as the OE APPS sensor is BELOW the tag voltage then the ECM will IGNORE the APPS voltage and use internal ECM software for Idling.

Yep,  I  always  believed that too..  " Ecm  manages  idle "         I wonder if  there is  some  'fighting'  between the  psg and  ecm  during  initial  spin-up..   until the voltages  stabilize? 

Would  a   stiff  turbo  (as in  cold  and  slow to spin up)   have any influence here?    

I realize   even a  'stuck'  turbo  will still allow  gasses to pass,  not as   well of course...    

Try doing the fuel pump priming procedure. Rock the key with no start.  Then start it and see what it does. Just sounds like air in the fuel at start??

Try doing the fuel pump priming procedure. Rock the key with no start.  Then start it and see what it does. Just sounds like air in the fuel at start??

I have done that in the past.  no change... I'll try it again who knows... thx

It's an OE and I am below the tag voltage... So the ECM should be commanding the correct idle info to the VP... so I am wondering that the 750rpm and not 800rpm that I should have along with the lope are somehow related.... is it possible that the VP is not processing the the idle commands / rpm properly because some component in the VP is breaking down? 

 

How far below the tag voltage?

 

Idle speed is based on Engine Coolant Temperature so the colder the engine the higher the idle will be. So if the sensor is off and showing higher temperature than normal then the idle speed is reduced. Also if the pop pressure is excessive high then the timing will be retarded on the injectors so then the idle speed is lower.

 

Very rare a VP44 can't make idle. But it more common to see injector issues creating weird issues.

Has anyone resolved the big cam lope.

I have noticed it a time or 2 with mine.only lasts a couple seconds but makes me nervous.

Regards Chris

I have not been able to figure out what is causing the issue yet.

I'm having similar issues. This weekend, I'm swapping out my 60s (I think 6 hole) for 100s (7 hole) and new connector tube o-rings. I'll report back...