hey guys

 

bit of a long story here but I need some help. my truck started to run a bit rough and losing a bit of power so I checked the lift pump pressure it was at 4 and zero at wot. so I changed it out new  pump pressure 17psi, then it started to start hard in the morning and showing a 1693 code. Eventually it died on my way to work and wouldn't start so I changed the injector pump and before I even tried to start it threw a 1689 and a 1693. I got the truck running no problem cleared the codes and took it for a drive and it had low power and died 3 miles down the road and the codes were back. towed it home bleed the injectors and it started again runs and idles fine until I take it for a drive dies after I take my foot off the gas it dies and wont start. I checked the harness connections they looked good put some dielectric grease on them pin 7 on the fpcm has 12 volts, the ground for terminal 6 on the fpcm seems good, pin 2 on the fpcm to pin 13 on the ecm has 0 ohms resistance, pin 1 and 2  has no continuity to ground open I guess. I am going to do the W-T ground mod next. If that doesn't help is it maybe my ECM?

Could be a bad VP out of the box. It does happen. Who did you get the VP from? Have done the diagnostics for the 1689 code?

 

You could hot wire the pump to be sure. There is an article here on doing that and Blue chip diesel has a good trouble shooting guide for the VP.  I cant link them on my tablet.

 

Edited August 7, 20196 yr by dripley

I read that article and will try that. I thought it was a bad vp at first but it seems to be having the same problems as the old one. 

It is possible it is the ECM. Just hate see you spend money on another ECM and it be something else. Thems pricey parts your swapping. Of course you can send your ECM in and have it tested. The hotwire test is good one to rule out the VP.

I did get the truck running with the vp44 hotwired. But I had to bleed the injectors to get it running. It seems like I'm getting air in the system so I'm going to try a clear hose between then filter and the injector pump and check for air that way. I have to bleed the injectors every time I shut it off now.

On 8/6/2019 at 3:16 PM, jackpressure said:

I even tried to start it threw a 1689 and a 1693.

 

P1689 is no communication between the ECM and VP44. Read over this and check your wiring for damage.

 

I did do the testing for the DTC P1689: NO COMMUNICATION BETWEEN ECM & INJECTION PUMP MODULE (OBDII).

 

Everything checked out except for pin 1 and 2 on the fpcm plug have no connection to ground. Pin 2 is suppose to have more than 5 ohms resistance and pin 1 I'm confused with it says more than 5 ohms replace ECM,  less repair short to ground. As far as I can tell my data link wires are open circuit to ground,

 

Pin 2 to 13 has 0 ohms, pin 1 to 23 has 0 ohms. Pin 6 has good ground. pin 7 has 12 volts, 

 

 I did the w-t ground mod yesterday I'll finish that up today and see if it helped also putting a clear hose in between the fuel filter and the injection pump to see if I'm getting air in the fuel system. Might be why I have to bleed the injectors to start it.

 

 

 

 

Basically...

 

End to end it should ohm out ZERO ohms.

 

Then end to ground should show infinite ohm to make sure there is no shorts to ground. 

 

I would have to say send the VP44 back most likely a bad PSG on top. Who did you buy from for a replacement VP44?

I got the running running again. I think I had a couple problems at the same time.

 I did the ground mod and put a clear hose in there to check for air, and it was sucking air tank was over half full. So I put 30 liters in bleed the injectors now it runs good. Only code left is the 1693. I dont think the truck running out of fuel would cause a 1689 but it's gone now.  Doing the ground mod must have cleared that up.

 

I installed a aftermarket lift pump beside the fuel filter and left the old  in lift pump in the tank. I'll have to pull that one out to see why its sucking air with over half a tank and by pass the suction hose.  

 

I most likely didn't need a vp44 at all but I'm just glad it's running again thanks for your help! 

I’m having a 1689 issue. Could you possibly identify where the can bus wires to test are? Or is it the flat 3 pin can bus plug a tuner plugs into?

On 8/13/2019 at 3:08 PM, jackpressure said:

I got the running running again. I think I had a couple problems at the same time.

 I did the ground mod and put a clear hose in there to check for air, and it was sucking air tank was over half full. So I put 30 liters in bleed the injectors now it runs good. Only code left is the 1693. I dont think the truck running out of fuel would cause a 1689 but it's gone now.  Doing the ground mod must have cleared that up.

 

I installed a aftermarket lift pump beside the fuel filter and left the old  in lift pump in the tank. I'll have to pull that one out to see why its sucking air with over half a tank and by pass the suction hose.  

 

I most likely didn't need a vp44 at all but I'm just glad it's running again thanks for your help! 

Is the tank 1/2 full or is the gauge 1/2 full. My 3500 v8 left me stranded a few years ago with gauge saying 1/2 full, tank empty, sender faulty 

Mine failed and left me struggling for a fuel station at 3/8 of a tank. New float assembly and back to normal and reading correctly.