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P1689 Very hard to start after VP44 replacement and ECM reprogram
Thanks for the torque specs! I was pretty sure I got it to those on the install, but I will be double checking this time for sure. The studs also backed out and I noticed when I pulled the pump that the threads were not in the best of shape so I plan to replace the studs and nuts as part of the process. the good thing also is pulling the cover will allow me to check and tab the kdp while I’m at it.
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P1689 Very hard to start after VP44 replacement and ECM reprogram
Not what I expected either! Thank you everyone for your help in diagnosing these issues!
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P1689 Very hard to start after VP44 replacement and ECM reprogram
Thank you! That was what I was thinking could be the issue. Just was hoping for something else possibly. I pulled the pump yesterday and I think I figured out the issue. A while back I noticed that the vp mounting bolts loosened up, I tightened them and didn’t think much of it. However it looks like the key came loose when the mounting bolts did, so now I’m going hunting for the key in the timing cover or oil pan.
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P1689 Very hard to start after VP44 replacement and ECM reprogram
Thank you to everyone for your help on this. Sorry I had not responded back sooner, the end of the summer got away from me and I haven’t been able to work on the truck much. I completed the ground relocation but the issue has persisted. I have noticed that the lack of power and the throttle cutting off is much worse when the motor is cold, and cuts out at 1500-1700 rpm. Once it warms up the throttle responds mostly normally, unless you really hammer it to over 2500 rpm. A local shop took a look at it and they think it is a bad VP. Does anyone have any additional thoughts that I could try before removing the VP for warranty service?
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P1689 Very hard to start after VP44 replacement and ECM reprogram
Great, thank you! I had to go quite a few places to find the right parts but I have them all and will be performing to mod this afternoon.
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P1689 Very hard to start after VP44 replacement and ECM reprogram
Thank you! I worked through that diagnostic to find the resistance in the ground at the vp44. I started taking things apart for the W-T mod but thought I might ask first. Especially since I have very limited experience with vehicle electrical systems. does the W-T mod address the ecm ground by the starter?
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P1689 Very hard to start after VP44 replacement and ECM reprogram
Good morning, I bought what I thought was a good deal of a truck during the pandemic, a 1998.5 3500 auto dually. This forum has been very helpful thus far but I feel like I have hit a bit of a wall and was wondering if anyone had any suggestions before I go down too many rabbit holes. Currently my truck is showing a P1698 code, which can be cleared but immediately returns. It s very hard to start but will get going, rev and not throw the code when in park or neutral. As soon as it is in gear and a load is applied the code pops and the engine derates. After installing the new vp44 it was running and staring very well. P1689 started suddenly on my way home one day about 300 miles after installing the rebuilt vp44 and has progressively gotten worse. Repairs before P1689 issues started Rebuilt VP44 from thoroughbred diesel last summer, tested this spring with a breakout box Edge tuner removed replaced grid heater relay, can’t remember code but bad circuit code popped Repairs since P1689 started Had ECM rebuilt and is installed with no change Tested continuity between vp44 and ecm, all good but 14 ohms on ground Cleaned all grounds on top of the motor Thank you in advance!
skiracer0112
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