This thread is where I will post updates of my modifications, issues i've had, and potential upgrades I'm considering.  

 

This page is dedicated to @TFaoro, because without him my truck would be bone stock still....

 

To start off, today my VP died.  It took me by surprise, as it gave no indication there was an issue.  But, it threw Death Code P1691, and that's that.  Good thing it died before I bought tires.

 

Is DAP everyone's first choice for a new VP?

 

Edited March 15, 20178 yr by trreed

5 hours ago, dripley said:

That's exactly why i did not ask. Very purdy but wallet unfriendly.

It's 6k for me to p pump and compound mine lmao 

6 minutes ago, trreed said:

I have fallen victim to a bad VP rebuild.  Tonight, with only 500 miles on the new pump, it quit on me, with the same P1691 code as before.  What are the chances of two PSG failures?  Also, there is something mechanically wrong with this pump, as I could hear the rotor turning in the pump as I was driving.....  So, a warranty claim will be started, and I will be putting the infamous "cold rod" pump on the truck for the time being, courtesy of @TFaoro...

Hmm I remember saying you should check AC noise "cough cough"

...maybe....  Though I should definitely check it now that I've had two PSG's die...  Any recommendations for reliable testers? Not gonna go with the Harbor Freight Special on this one.

9 minutes ago, trreed said:

...maybe....  Though I should definitely check it now that I've had two PSG's die...  Any recommendations for reliable testers? Not gonna go with the Harbor Freight Special on this one.

Fluke. They aren't cheap, but they last forever and are accurate 

The infamous Cold Rod VP44 has been swapped into my truck to allow me to start a warranty claim on the new SO pump. I do have a miss at idle, though it is not as bad as Tyler's was. The truck idles around 875 rpm.....

At least the transmission and differential don't leak anymore....

Borrow a meter. I will second fluke but I do not own one. lol

I'll be coming up to castle Rock Friday afternoon to help a guy out.  I can't check for you if you head down

That'd be great!  i'll text you closer to and figure out a time and whatnot

Ok guys humor me some.  I have had three different VP's in my truck over the past two weeks and every one has done the same thing.  Every now and then, I'll go to push the clutch in, the truck will rev up to 2000 rpms and die.  Every time I will get codes P1691, P0121, and P1693.  I have been having APPS issues as well, specifically the 5 second dead pedal.

 

Since i have had three pumps do this, is it possible that the APPS is causing these issues?  

Let me read into what 1691 is supposed to mean.  I am starting to think you might have some sort of short in the cnabus wiring region.  Something to make messages not make it through. 

Everywhere I've read says P1691 is an internal fueling control failure.  Though that doesn't make much sense to me.  When the truck quits, you can crank it and it will act like a dead VP.  But if you let it sit for 1-3 minutes, it'll fire right up like nothing happened.  So maybe not a physical short?

Edited April 3, 20178 yr by trreed

Have you tested for AC noise from the alternator? 

 

Most likely the PSG on the VP44 has taken on damage from AC noise. 

 

Quote

Fuel injection pump controller calibration is monitored with ignition on engine off and with engine running and no CAN BUS errors reported. DTC may be set when PCM fuel injector pump controller and ECM RPM are mismatched or fuel commanded does not equal amount fueled.

 

 

I think the PCM part is a typo. I think it's suppose to be PSG.

Ha, gonna post this before Tyler says anything, but I have yet to test for AC noise.  Might be meeting with @Me78569 this Friday to check it.  However, I would think that if the AC noise was bad enough to damage a PSG in 500 miles, it should've affected the ECM by now

 

Not always. Just depends on which device is weakest to the frequency and voltage levels. Typically the VP44 is the weakest between the ECM and VP44. Being you are a manual transmission you may or may not get surging cruise control issues. 

Hmmm.  Will definitely be testing that sooner rather than later. And maybe taking the car tomorrow

 

2 hours ago, Mopar1973Man said:

Not always. Just depends on which device is weakest to the frequency and voltage levels. Typically the VP44 is the weakest between the ECM and VP44. Being you are a manual transmission you may or may not get surging cruise control issues. 

I HIGHLY doubt that at 500 miles on a new pump and 20 miles from the pump that I pulled would cause it that quickly. 

 

First place I would start (before you meet Nick) is fix the GARBAGE battery cable ends, clean all grounds, remove all electrical connectors and clean / fill with dielectric grease, and open the wiring to make sure you don't have a chaffed wire between the ECM and VP. 

Edited April 4, 20178 yr by TFaoro

I agree with Tyler.  Dielectric grease is your friend.

I just finished installing a Timbo APPS to fix my intermittent dead pedal issues.  Installation went smoothly.  Now i'm just waiting on the mailman to show up with my egt probe and stuff to fix my angry, leaking turbo......  He did bring a package for a project I'm starting to gather parts for (pic below is relevant).... more on that later...

I'm pretty certain I've figured out my VP issue!  I tried switching the horn and VP relays under the hood, and the problem has yet to return.  However, when I went to use my horn the other day, it stumbled and finally sounded about a second after I hit the button...

Oh isn't that a kick in the........

That would take some of the mystery out of the pump failures as far as the Quad is concerned.