Wierd Power Problem

[tragicwagon]

It's been going on for about 30k miles and Ive kinda gotten use to it,but some days the truck runs good,some days it dont,when it runs good it gets between 18 & 20 mpg, when it dont it gets 15 & 16 mpg. dosent seem to be weather related,and Ive checked it on repeated trips and fueling at the same place. sometimes I can shutdown and 20 minutes later fire it up and go down the road and notice a change in power,dont know if turning the switch off or on is resetting something or what,even the wife notices it,so Im not imagining it. I pulled the IAT,it looked fine,clean and no soot. I would like to get 18 & 20 mpg all the time (hwy),not to mention constant power. anybody have any advice? Ive read everything I can find on low power problems,but nobody else has mentioned a change from good to bad like this.



hope someone can help!

PS,been to the dealer twice,they dont have a clue.

 

[DavidD]

Super strange, I would consider the ECM or the Banks kit. I dont know anything about he Banks but maybe there is a lose connection there and it working sometimes and sometimes not? It does sound like it would be electrical and not mechanical in nature though. What happens when you turn the banks off? try to do the process of elimination. Dave

 

[tragicwagon]

sorry should have been more informative









The problem existed before the banks,although with the ottomind does seem to enhance the symptom. probably should have fixed the problem before adding power enhancers,but the local dealer couldnt find anything wrong . The closest cummins shop is about 200mi away,do the cummins shops work on the electrical on these trucks or just mechanical?

 

[Tom G]

Good Days and Bad Days

My truck does the same thing.



I can start the truck up and hear a difference in the sound it makes. My truck has also been to the dealer three times and they could never find anything wrong... i. e. no codes, loose boost hoses, filters, fuel pressure, (I replaces IAT sensor - no help), flashed and re-flashed the ECM, etc. I have tried the old on-off-on-off-on key trick and never observe any codes. It will do it when cold or when hot, with Texaco fuel or Pilot truck stop fuel. It does it at night and in the daytime. It happens about 20% of the time.



On a good day the truck runs great. Shut the key off, go pick up some Rotella at Wally World and then re-start the truck and it seem like I've lost 50 h. p. . Shut it down and re-start it and it's better. What can you expect for only $29,950 :-(



Sort of learned to live with it or maybe given up trying to find a solution. Maybe one of the diesel experts here on TDR will have some ideas. I keep reading and hoping...

 

[Silver Bullet Ram]

When my fuel mileage went south i took it to the dealer, they couldn't find anything, took it to a diesel mechanic, they couldn't find anything. I talked to a guy at work who had the same truck as me, he said go out and flip the lever up on the side of fuel filter. If something came out as soon as i flipped it, i had water in my fuel. Truck ran better after that. When the truck runs like crap and the fuel mileage decreases i flip the lever and the problem is solved. Good fuel is hard to get these days. That might help you and it might not.



Gary

 

[Tom G]

Thank You For the Imput

Hi Gary and Thank You For The Input:



Have lifted the lever a couple of times and never get anything other than diesel fuel.



Just changed the fuel filter after 15,000 miles and it looked almost like new. Looked down in the cartridge holder/canister after removing the filter and all I could see was one drop of water. The Water In Fuel (WIF) sensor was also very clean but cleaned it anyway before putting in a new Fleetguard fuel filter.



Oh almost forgot; cut the plastic ends off the Mopar/Fleetguard filter and spread the filter folds open and let it dry for a couple of days. The filter was the color of diesel fuel but only one or two small specks of dirt could be found. At this rate 30,000 miles could easily be driven on the filter. Have been lucky so far I guess and have been getting very good fuel here in Lake Havasu and local desert service stations/truck stops.



Thank you again

Tom G.

 

[Mojo293]

And I thought it was just me. My truck does the same thing. One day it's floor it and go, the next time floor it and go, just a little sluggish. I also have a friend with a 2002 who complained about the same thing just the other day. I had never mentioned it to him, he just noticed it on his own truck too. I can't explain it and have no idea why these trucks would do this. But doesn't it have to be computer related?

 

[Tom G]

Computer Related?

Hi Mojo293:



I would agree that it might be computer related But how do you hook up an instrument(s) to monitor the computers functions? Ever try and get a copy of a computer program from a dealer or Cummins and figure out how to diagnose it with a laptop? Wouldn't it be nice if we could get an instrument from our dealer(s) which would continously record engine performance over a period of time followed by an analysis of the data? Be a cold day in h... before that ever happens.



I am SURE someday we will find out why this happens. Yesterday was thinking just maybe someone should put together a letter to Cummins and ask them to specifically state what the differences are between an engine headed for a 2500 and 3500 are. It doesn't take a genius to review this website and see that 3500's get significantly LESS mpg than 2500's do and I just don't buy the fact that it all due to bigger springs, wheels, tires and fenders. There is more to this than meets the eye.



Tom G.

 

[IdaH.O.Train]

I posted about this a few days ago. Funny thing is, my '00 V-10 did the same thing, except with that one, it usually happened when the fuel gauge got to about 1/4 full, then it would have the throttle response I expected. With my '01, there is no rhyme or reason; sometimes it is snappy, sometimes it's not.

 

[Marco]

MAP sensor

That's most likely the MAP sensor.

Been there done that. New sensor fixed that problem.

Consider two things. The OEM sensor is designed for pressures up to 20-25 Psi. When you BOMB the engine where does your boost numbers go? Waaaay too high for the stocker.

With stock boost levels, well sh** happens...



Marco

 

[Tom G]

Marco Is Here

Hi Marco:



Thank you for reviewing this thread and commenting on our changing performance issures. It's very nice to have you out there and commenting when you have the time



I will go to the dealer and order a new MAP Sensor this week and see if that fixes the problem. I did replace the IAT (Intake Air Temperature) sensor and compared the old sensor to the new sensor and your readings. The old sensors resistance reading was 1. 96% BELOW your data point at 64 degrees F. Since it was fairly close to the orginal and your readings I didn't check the new one at different temperatures. Saved the old sensor just in case. Don't know if it's just my wishfull thinking but I think the engine sounds slightly quietier.



How much of a resistance change would it take to have an affect on the timing?



Thank you again for sharing your knowledge.



Tom Garven

Lake Havasu City, AZ USA

 

[tragicwagon]

I Thank all of you for the replys,dont mean to wish anyone bad luck but Im glad to see that Im not the only one with this problem. MARCO thanks for the insight,I dont know any thing about sensors or electrical,but now we have something to try . TOM G,good luck with the sensor swap,hope youll post the results. called my dealer today they told me that the cummins didnt have a map sensor so I said "you know the thingy behind the fuel filter,in front of the IAT,the one that measures the boost" they said its called a boost pressure sensor,anyway they dont keep it in stock,they could have it in 10 days for 132. 52 :--). hope your steeler is better than mine.

 

[obert]

MY TWO CENTS

Ive had a few electronic demons posess my truck, but this one hasnt shone up yet. A recent updat of the ECM curred evrything-- at least so far



To Tom G: If any of you have deepr pocets than I, get a palm pilot. The last time I was at the Cummins shop (getting parts for work... . ), there was a mat on the parts counter that described a cartrage or disk of some sort that could be plugged int the palm pilot, then an adapter harness went to the data port on the engine. I think it was like $250. What do palm pilots go for? Also, Im not in the automotive field, but i belive the "on-off" deal with Chry. vehicles went when they finaly adopted OBD2 onboard diagnostics. (all you gotta do is hold a button down on a Bobcat)



:--) TRAGICWAGON!!!-- I repalced my broken boost sensor from Cummins for about $45+ tax

 

[Tom G]

To Tragicwagon and Obert

Thank you gentlemen for all the help. Planning on going to the stealer tomorrow and will be checking out the price for the Boost Sensor (BS).



Got a real kick out of your conversations with the dealer regarding 'no MAP (BS) on the Dodge'. My parts counter guys are pretty good really. They have a computer terminal sitting where they can turn it around and show you a picture of the part and other information including its cost. Most of the time they give customers who have purchased their trucks at the dealership a break on the parts but we shall see.



I would be happy to post the results of BS change out after it has been installed. This weekend will be dedicated to drilling and tapping for the installation of my pyro and boost gages (boost gage is in route via UPS). Painted the pillar a color matched tan today.



Oh yes, a Palm would be sweet - lets see, how many days till Christmas



Tom G.