[carfreak614]

Need some opinions and I'll try to keep it short,

Truck: 1999 Dodge Ram 3500 5.9l turbo Auto 2WD. Truck hasn't ran since I bought it

Lift pump was bad so I replaced it with another stock unit (Didn't realize I shoulda upgraded but here we are).
Added a fuse/relay to the pump that uses the signal from the ECM to activate.
Re-terminated the battery cables and grounds going to both batteries with military style connectors due to voltage issues and poor fitment.
Went through any grounds under the hood that I could get easy access too and cleaned/greased em (still need to check passenger side motor and driver side ground by starter)
Pulled ECM out to clean contacts to motor and re-installed

I'm currently pulling both p1688 and p1689 codes ( and p0230 but that's the lift pump wiring), so from what I've gathered the VP44 is toast. But the weird part is how the truck is acting. If I have the relay for both the injection pump and lift pump installed, the lift pump will not run. If I remove the relay for the injection pump, the lift pump functions as it should (short bump on ignition and runs for 25ish seconds if starter is bumped). I get good signal voltage to the injection pump relay either way, but the signal for the lift pump goes from 12V to around 8ishV if the injection relay is installed. My first thought is a short or ground issue somewhere in the wiring but I'm starting to wonder if the dead VP44 might be causing this, or possibly a ECM issue.

Anybody else experienced this or have any thoughts?

 

[bigfish95971]

Welcome Have you tried bleeding the VP correctly. I would put the wiring back to stock and make sure lift pump is dong the bump 25 second run and putting out at least 10 lb pressure. Charge batteries to full charge.
Loosen the fittings on the head on injector lines 1, 3, and 4 cylinders.
Chrank the engine over for 10-15 second intervals with 1-3 minutes rest breaks to cool starter, Do this for 10-20 sessions or until it starts t o SPRAY oiut around the fittings. When it sprays start closing the fittings and it should start to fire and run if VP is good. If not try "hot wiring VP" if you think it is not getting juice. When cranking dribble or bubbles in not spraying as needed. Try that and get back.

 

[bigfish95971]

Does Wait tto start light come on every time you turn the key to ON and stay on for several seconds if under 60 degrees there? At least a second if warmer.

 

[afterburn549]

Have you done the VP 44 hot wire test?
Next, there is nothing wrong with the pump on the side of the engine, as long as you run a Fuel p gauge as you should with all the electric junk.

 

[carfreak614]

Sorry for the delay, been helping the MIL move. To add some clarity though:

The lift pump is the stock style mounted to the driver side block. Originally I swapped the pump out and was getting the same results with the stock wiring. I installed the fuse/relay due to the fact that I may need to run the signal wire to an ignition source if the ECM is suspected to be the issue. If I jump the relay the pump runs fine.

When you turn the ignition on, sometimes you get the initial bump (but not always) and I get the wait to start light that goes out shortly. But I don't get the 25 second run if you bump the starter. Due to this I haven't tried the VP hot wire test yet.

Edit: I also wanted to add that I tested at the stock connector for the lift pump and get a good test light for the ground side but not for the positive side (yl/wt) wire. I am showing 8ish volts from the positive side, which is odd that the circuit wont light.

During the troubleshooting of this, is when I discovered that the lift pump functions fine if the VP 44 relay is unplugged. This has led me to suspect the ECM since it seems like I only have trouble if the ECM is powering both or that I have a wire issue somewhere. I was told that the 2nd gens should have a limp mode that prevents the truck from running, so a bad 44 may cause the ECM to not send a good signal to the lift pump, but from what I've gathered I don't know if there's any truth in that statement.

 

[bigfish95971]

I do not believe there is any truth to this statement at all." I was told that the 2nd gens should have a limp mode that prevents the truck from running, so a bad 44 may cause the ECM to not send a good signal to the lift pump, but from what I've gathered I don't know if there's any truth in that statement." No "limp mode".

Check WTS light closely some more, Come on EVERY time to ON instantly? Stay on for grid heaters if cold? Go right off if warm, 60*? Any codes ECM related?

 

[afterburn549]

But if a Hotwire test is done, the ECM gets no signal from it.
I have done this and the pump must have run.

 

[carfreak614]

I do not believe there is any truth to this statement at all." I was told that the 2nd gens should have a limp mode that prevents the truck from running, so a bad 44 may cause the ECM to not send a good signal to the lift pump, but from what I've gathered I don't know if there's any truth in that statement." No "limp mode".

Check WTS light closely some more, Come on EVERY time to ON instantly? Stay on for grid heaters if cold? Go right off if warm, 60*? Any codes ECM related?

WTS seems to be working properly. Comes on for about 6 seconds when cold, then goes off after plenum warms up. Goes off if already warm (in OH though so I wont see above 60 for a couple days). Just ran out to get codes and got the same ones:

P1688 Internal Injection Pump Failure
P1689 No Communication Between ECM and Injection Pump
P0230 Transfer Pump Circuit out of Range

I need to run down and get a fuse holder but I may try to jump the lift pump long enough to try the vp44 hot wire test today

 

[bigfish95971]

You are most likely going to find the 1688 code to be accurate. the 1689 is due to the 1688 failure. Need VP44.

 

[afterburn549]

Did this ever pass the Hot wire test?

 

[carfreak614]

So I finally got out yesterday to do some more tests. I tested the lift pump wiring before the factory plug and checked both lines (even cut out the factory splice just to be sure) and I'm getting the same results. Made my jumper for the VP44 and cracked fuel lines 1,3, and 4 until I was getting fuel. Still won't fire even with the jumper.

P-Pump conversion isn't in the cards financially at the moment. What companies does everybody suggest for a replacement? Some were recommending thoroughbred diesel but I've seen some worrying reviews on here. I'm leaning towards Blue Chip Diesel or DAP.

 

[bigfish95971]

That is odd, 6 seconds for ECM. Cold should be about 30 seconds or more or just one second for when over 60*. Can you post a video of the injector fittings squirting fuel? If they are squirting enough fuel at high pressure it should fire when you close the fittings.

 

[carfreak614]

Got rained out today, I'll try to get out tomorrow and get a video

 

[carfreak614]

Got a chance to mess around with the truck today. The video below shows line 3. I had videos for the other 2 lines with terrible lighting, but the results were pretty similar. This was with the jumpers connected from the VP44 to the battery (with a fuse of course).

http://imgur.com/zTwCfxw

With it being around 54° today I got some different results. The Wait To Start light only stayed on for about 3 seconds when I first turned the ignition on, which seems pretty short. I bled all three lines til they had fuel coming out and tried to start the motor but still couldn't get it to fire after 4 attempts (had to wait on the battery to charge a little more). I also had a whine come from the driver side of the motor today when I kicked the ignition on the 2nd or third time. Was too short for me to be able to pinpoint but it was definitely in the VP, ECM, Lift Pump area. Couldn't get the truck to replicate it after numerous tries.

I should also mention that I came across another thread mentioning a similar issue where the ECM was putting out weird voltage to the lift pump (around 8V) and the remedy appeared to be a crankshaft sensor. The truck is not throwing a code for that though.

 

[bigfish95971]

Sorry to say it but that is just a dribble, likely bad VP44.

 

[afterburn549]

It sure looks that way to me too ..
If she will not start up hot-wired and idle normally, that condemns the VP44.
You have to bleed it in the normal fashion first . ( Just have the nuts slightly loose on the fittings as above)
Enough to let the air and fuel squeeze out, but not let air back in. You do not even have to do them all, just the 3 most EZ ones

 

[carfreak614]

Alright thanks for the help. I'll post an update after I get the new VP44 in.