Archived Fuel gremlin?

[mstephenson]

Everybody, I need help. My truck is stumbling/decelerating at RPM's 2000ish. Between speeds of 55-70 I would say. It feels like I let off the pedal, but I don't. It starts out slight and builds up intensity and is obvious. I have changed the fuel filter. FP guage says 12. 5-13#. I read a thread about the APPS and so I disconnected the batteries +1hr, reconnected, and pressed the pedal slowly, but only once. That seemed to work for a few days, but now it's back. Also, I don't know if this matters, but my cruise will turn on, but not engage. I have a RR4 and watch the fuel rate (gph) drop when this is happening. The RPM's drop too (~100) and sometimes the speed (1 MPH). I also read a thread somewhere the fuel rate at idle should be . 5 gph. RR4 is telling me . 09-. 16 gph. I have not checked/cleaned the IAT, MAP, or speed sensor. I don't know how to check the volts/ohms. I don't have a scan tool. If that needs to be done give directions and my brother can show me how. This is nerve wracking to say the least and I know it will eventually leave me somewhere with no help.



Any suggestions?



If it's the...

APPS - new ($440 at stealership) or used

VP44 dying out - new, used, or rebuilt

ECM - do I have a choice



Thanks, Michele, Brenham, TX



I can't get my profile to read so here it is:



99QC 4x4 5-sp, +160K, BD-brake, RR4

 

[2-ND TIME]

Fuel gremilins

Sounds like a defueling problem to me. For this is what mine is also doing . By chance what is your Month, Day , Hour MDH in the bottom of your sticker on the door panal? Does it sound tinny when it is doing this If you are able to remove the APPS and measure the resistance of it it would tell if it is a problem part. Have the spects if you wish. Are you able to monitor the boost when it is doing this cummins makes a three wire to moniitor this price here is $130. 00 . do you have boost at all? If you don't have a multimeter thay are reasonably cheep to buy and can tell you how to use it. I suspect ths APPS .

 

[mstephenson]

i don't know exactly when manufactured (01-99) since i ordered it at Christmas and got it first thing in feb.



haven't measured anything. would like the specs though. thanks. can i measure APPS with a voltometer thing?



my bro also suspects the APPS. if so then i'm going to try to buy used if cummins doesn't have this part. they're always cheaper than the stealership ($440).



i have boost, but i don't know if it's enough. ~14. 8. it is being measured by the RR4 so i don't know how accurate that is since everything is being read from the ECM. it's hard to watch the road, watch the tach and watch the RR4 w/o running over everything in my path. will also check that this week.



also, i have no smoke when i get on it. don't know if that matters.



thanks 2-ND TIME