Frustrating.
#1
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Frustrating.
Hi guys. After changing the LP and the fuel filter I have now driven the truck for about 5 consecutive days with no problems. The truck seems to run fine. Though, I have never owned a diesel so I have nothing to compare it to. Well tonight on the way home I start up a pretty long hill ( not steep just long) and I press the pedal and it does nothing. I lift completely off the pedal and go, back down and it runs fine. This happened about 4 different times tonight. I stopped by Autozone after it did this and NO CODES. What's up?????
#4
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You cannot check output pressure of the VP44 (injection pump), however you can check the lift pump pressure. The lift pump is the pump that sucks fuel from the tank to feed the VP44. Ideal output of the LP is 14 PSI. Since you did change the fuel filter and were able to prime and restart the system, this indicates that you have adequate pressure (or just enough). But, you still could have a failing lift pump (these pump are notorious for dying slowly, losing pressure and output over time, and eventually taking out the VP44 too from fuel starvation). I strongly reccomend getting a fuel pressure guage to be absolutely sure on this though.
Your problem may not even be fuel related. What you described sounds a lot like the infamous "dead pedal". Your APPS (accelerator pedal position sensor) may have a dead spot, or just need to be ce calibrated/reset.
APPS reset procedure here.
Be forewarned though, this could also be a sign of impending injection pump failure. Several people have had that happen before thier injection pump failed. Normally a code will come up though, P0216 (injection pump timing control failure, aka "VP44 death code")
Let us know what you find out.
Your problem may not even be fuel related. What you described sounds a lot like the infamous "dead pedal". Your APPS (accelerator pedal position sensor) may have a dead spot, or just need to be ce calibrated/reset.
APPS reset procedure here.
Be forewarned though, this could also be a sign of impending injection pump failure. Several people have had that happen before thier injection pump failed. Normally a code will come up though, P0216 (injection pump timing control failure, aka "VP44 death code")
Let us know what you find out.
#5
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You cannot check the VP44 output pressure. The fuel injection pressure is really high, around 4,000 PSI or so. The pressure isn't simply lost, rather the VP44 returns to idle condition, either from a dead pedal (APPS sensor), or a failing control circuit on the VP44.
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Mine is a 98.5 24v. Will it still have the APPS. Also, fuel pressure is about 13psi (idle) and 10psi (WOT). I just replaced the LP a week or so ago.
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#8
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My problem is a bit different -- trouble starting when hot and sometimes when cold too. I recently installed a fuel pressure gauge and usual reading is 15 psi when I bump before start, 13 psi at idle, 10 psi at regular driving and 5 psi wot. Ny mistery is when I start cranking, the psi drops from about 15 to nearly nothing and the gauge justs flutters a bit near the botttom. Is it normal for the pressure to drop like that when cranking or is that my starting problem? Yesterday when it was not starting, I put a jumper on it and it took right off even though both of my batteries are at about 13.8 v when I turn the key on. If I crank long, the in dash voltmeter drops to about 9.
Thanks for any help you can give me. Bud
Thanks for any help you can give me. Bud
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Bud, when it does start...do you get white smoke? Hard starts when warm and white smoke are classic signs of a dead Injector Pump (VP-44).
You might want to have the truck scanned for codes and measure fuel pressure at the test port on the VP-44.
You might want to have the truck scanned for codes and measure fuel pressure at the test port on the VP-44.
#10
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Yep that's what mine did on a new vp44 fresh from dodge. No codes or white smoke, just occasional hard start when hot. I finally convinced Dodge to try a new injection pump and that took care of it. Good Luck!
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Bud, sounds like you have a voltage drop while cranking that temporarily pulls from the lift pump supply. You could have 1) bad batteries 2) loose connection 3) worn contact tips in your starter that is causing a high AMP draw. Check all the above and you should have ample voltage supply to the pump. Not saying it will cause the truck to start any easier it will just keep your LP voltage (fuel pressure ) from falling off so much.
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Bud, sounds like you have a voltage drop while cranking that temporarily pulls from the lift pump supply. You could have 1) bad batteries 2) loose connection 3) worn contact tips in your starter that is causing a high AMP draw. Check all the above and you should have ample voltage supply to the pump. Not saying it will cause the truck to start any easier it will just keep your LP voltage (fuel pressure ) from falling off so much.
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Thanks guys! I have no codes and i don't think I have white smoke. In fact, when it is going it runs like a charm, no dead pedal etc. I'll try to find the contact tips in the starter and I will see if I can figure out how to measure the voltage with a pigtail while running-my vom has pretty short leads. Thanks again! Bud