Engine/Transmission (1998.5 - 2002) 2001 Dies when put in reverse or drive

[DonFitzwater]

2001, reman vp-44, new lift pump (in tank mopar setup), low pressure fuel warning. 94000 miles, Stock truck, automatic. Truck wouldn't start periodically and had multiple pump failure codes. Put in new pump and lift pump, fired right up. One day after installation of fuel pumps (and fuel filter) engine runs great with the exception of dying when put into reverse or forward gear at times, not all the time. The engine does tend to surge a little bit occasionally but runs great other wise. Fuel pressure is 10-11 psi at idle and 8-9 on a hard pull. No codes, lights or any other indication of issues except dying out. Any thoughts of where to look? I hope I didn't get a bad VP-44 from reman.

 

[JLandry]

I'm wondering if you don't have an intermittent transmission problem.



What are the idle speeds in neutral and when stopped in gear?



Where did the reman VP44 come from?



John L.

 

[DonFitzwater]

The pump is a stock reman from Industrial injection. The lift pump is a factory kit. The engine runs great other than the dying.



Rpm's in gear are approx 675-700. It doesn't die all the time. If you start and drop into reverse and then immediately go into drive it will die. It doesn't die under normal driving conditions, only when you select drive or neutral about 50 percent of the time. Is there any apps adjustment I need to do? I didn't mess with the apps when I replaced the pump. Just moved it out of the way.

 

[DonFitzwater]

Idle in neutral is approx 700.

 

[JLandry]

OK... it seems like the engine idle speed on your truck is too low. Idle speed with the transmission in Park or Neutral should be approx. 800 rpm (check your engine data label to verify). The idle speed on my truck when stopped and in gear, even with a low-stall torque convertor which really loads the engine, is approx. 750 rpm. When the ECM gets an "idle-on" signal from the APPS, the idle speed is controlled solely by the Fuel Pump Control Module (injection pump computer) and not by the ECM or APPS. In other words, the ECM tells the VP44 to "go to idle" and let's the VP44 do its job. I'm not sure if the VP44 normally uses any external references for controlling engine idle rpm.



You can verify the idle rpm isn't being influenced by anything outside the fuel injection pump by simply disconnecting the VP44 wiring harness then hot wiring it per instructions you can find here on the forum (do a search). Start the engine and if the idle speed is the same with the VP44 hot wired, then you know the problem must be internal to the VP44. If the idle speed increases significantly with the VP44 hot wired, then something external to it must be causing it to be lower when connected... like possibly a bad sensor.



If you are able to narrow down the problem as being internal to the VP44 and it's still under warranty, you may want to give Industrial Injection a call.



Please keep us posted,



John L.

 

[DonFitzwater]

Will do, thank you!

 

[JR2]

There is a TSB about this problem as well... . something about cold weather flash. . My truck does the same thing but I blame it on the tight torque converter and big injectors.

 

[DonFitzwater]

For the last two weeks I have been keeping any eye on this thing and it hasn't died for had any running issues. No explanation other than surging stopped and now the truck is running well.

 

[DonFitzwater]

I know this is an old thread but resolution has finally come about. The oil pressure sender was grounding the 5 volt circuit. Replaced the oil pressure sender and the years of dying out has stopped.

 

[tgee43]

my 98 vp44 has similar deal, when cold, I put in gear, it stalls. It will start right right up after. If I let it warm up awhile, it wont do it. It's done this with the previous vp44, and still does with the Blue Chip I have now. Seems to have gotten worse with age. Seems like ECM is slow to compensate for load,or torque converter putting too much load on engine at idle.