Engine/Transmission (1998.5 - 2002) P0122 = new APPS??

[tmacc]

OK for the whole gory preamble to this thread, look here... .



https://www.turbodieselregister.com...8-5-2002/231612-hard-starting-p1693-code.html



So after installing the reman'd VP44, it appears to have been a waste of money. In hine sight, maybe the fact that the the truck ran fine once it started should have been a tip off. I now get a P0122 code, which I didn't get before. Does this mean I need to replace the APPS? I checked the connection again this morning. It was tight. I hate to just throw parts at this thing.



Now, what to do with the old VP44 which is probably fine, but I have a $400 core charge on. Augh!

 

[HHhuntitall]

First, do a test on your APPS. Read up here..... https://www.turbodieselregister.com...02/186808-dead-pedal-apps-tps-adjustment.html



Then it can tell you if that's the route you need... . Good luck!!

 

[hcole]

I would try a couple of things. First, lets try to eliminate air getting in the system. I think its OK but it can be checked by parking the truck front end lower than the back so the fuel has a harder time flowing back to the tank. The more radical angle the better. Next, I would disconnect the fuel pump from the ECM and power it from a relay. This accomplishes 2 things. One, it takes the current that the fuel pump uses off the ECM 's total current load ( I am told the fuel pump isn't even fused) as the voltage to the VP44 can be dragged down by the fuel pump and bad connections. Second, by putting in a relay, you can tell when the pump is on by watching the relay operate. The relay coil is hooked up to the wire that went to the fuel pump originally and the normally open contact on the relay can now come from the battery and thru the contact to the pump. Now, you should have FULL voltage to the ECM at all times. Its cheap to try.

 

[tmacc]

I'm pretty discussed at this point. We're heading out for a week on the river. I'll be in a better frame of mind when we get back.
Thanks for the tips. I'll check them out next week.

 

[98whitelightnin]

There are alot of people out there that would give $400 for a good pump if their's is dead. I went through the same thing a few years back and ended up getting one of Timbo's apps and its been running great ever since.