Lack of power...
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Joined: Apr 2003
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From: Cummins Technical Center, IN
If it was the air filter, you'd have black smoke and high EGT. It's definitely a fuel problem. You are getting plenty of air to burn the fuel. But you aren't getting enough fuel.
So think this through:
What conditions must be met for the computer to send fuel to the engine? What can prevent the fuel from actually getting there?
In order to send fuel to the engine, the computer must see 1) APPS signal telling it the pedal position asking for more fuel, 2) MAP sensor reading telling the ECM that there's enough air to burn the fuel, 3) IAT tells the ECM how dense the air is, so it can calculate max allowable fueling vs boost.
What can prevent the fuel requested from getting to the engine? 1) Clogged fuel filter (which you changed), 2) Obstructed fuel pickup in the tank, due to bad fuel or debris 3) a kinked or dented fuel line that restricts flow 4) a leak in the fuel circuit anwhere from tank pickup to injector.
Personally, I'd suspect the MAP sensor first, then possibly the APPS. MAP is cheaper, so replace it and go from there. Or at least TEST it. Voltages should be in the factory service manual, IIRC.
jmo
So think this through:
What conditions must be met for the computer to send fuel to the engine? What can prevent the fuel from actually getting there?
In order to send fuel to the engine, the computer must see 1) APPS signal telling it the pedal position asking for more fuel, 2) MAP sensor reading telling the ECM that there's enough air to burn the fuel, 3) IAT tells the ECM how dense the air is, so it can calculate max allowable fueling vs boost.
What can prevent the fuel requested from getting to the engine? 1) Clogged fuel filter (which you changed), 2) Obstructed fuel pickup in the tank, due to bad fuel or debris 3) a kinked or dented fuel line that restricts flow 4) a leak in the fuel circuit anwhere from tank pickup to injector.
Personally, I'd suspect the MAP sensor first, then possibly the APPS. MAP is cheaper, so replace it and go from there. Or at least TEST it. Voltages should be in the factory service manual, IIRC.
jmo
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From: New Meadows, Idaho
Hey Hohn...
Thanks a bunch... But could you look up those voltages and the pin out assignment for the MAP sensor. I've got no books for this beast... I rely on you guys here for my troubleshooting...
I'll go from there then... Check the MAP sensor as soon as I know the voltages and pin assignment...
Edited: While I'm at it... Does anyone know the Cummins Part number for the MAP sensor? I just found out the NAPA doesn't carry it at all... Dealer only item! I know better to ask here first!
Thanks a bunch... But could you look up those voltages and the pin out assignment for the MAP sensor. I've got no books for this beast... I rely on you guys here for my troubleshooting...
I'll go from there then... Check the MAP sensor as soon as I know the voltages and pin assignment...
Edited: While I'm at it... Does anyone know the Cummins Part number for the MAP sensor? I just found out the NAPA doesn't carry it at all... Dealer only item! I know better to ask here first!
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Joined: May 2005
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From: Missoula, Montana
numbers for 98.5 - 00
http://www.dodgeram.org/tech/dsl/Facts/98ISBspecs.html
numbers for 01 - 02
http://www.dodgeram.org/tech/dsl/Facts/01ISBspecs.html
Chart for IAT
http://www.dodgeram.org/tech/dsl/sensors/IAT/clean.htm
Not sure where one is for MAP
Randy
http://www.dodgeram.org/tech/dsl/Facts/98ISBspecs.html
numbers for 01 - 02
http://www.dodgeram.org/tech/dsl/Facts/01ISBspecs.html
Chart for IAT
http://www.dodgeram.org/tech/dsl/sensors/IAT/clean.htm
Not sure where one is for MAP
Randy
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From: New Meadows, Idaho
Originally Posted by newriverSpecon
numbers for 98.5 - 00
http://www.dodgeram.org/tech/dsl/Facts/98ISBspecs.html
numbers for 01 - 02
http://www.dodgeram.org/tech/dsl/Facts/01ISBspecs.html
Chart for IAT
http://www.dodgeram.org/tech/dsl/sensors/IAT/clean.htm
Not sure where one is for MAP
Randy
http://www.dodgeram.org/tech/dsl/Facts/98ISBspecs.html
numbers for 01 - 02
http://www.dodgeram.org/tech/dsl/Facts/01ISBspecs.html
Chart for IAT
http://www.dodgeram.org/tech/dsl/sensors/IAT/clean.htm
Not sure where one is for MAP
Randy
As for codes... None! I've got no codes...
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no way you can get any readings on that map? (scan tool?) Would be nice to see the ECM sees versus your boost gauge. They should be reading the same (except with the DRB you have to subtract the atmospheric reading from what you see on the scanner).
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From: New Meadows, Idaho
Originally Posted by J BODY
no way you can get any readings on that map? (scan tool?) Would be nice to see the ECM sees versus your boost gauge. They should be reading the same (except with the DRB you have to subtract the atmospheric reading from what you see on the scanner).
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From: New Meadows, Idaho
Originally Posted by J BODY
I thought I had a extra MAP sensor in my little drawer of tricks, but no go.
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From: spokane/N. ID
Are you running a comp? I occasionally get lame acceleration and if I kill the comp it comes back to life. It might pay to check the map and IAT connections, Ya know there was a bunch of guys unpluggung the MAP but they were all running boxes,
How does it rev with no load? flat ground? just fishing but if you have fuel and air it must be a haywire signal or signal loss somewhere....how is the battery ground cable connections? wierd stuff happens on these from bum connections why can't they be obvious like a flat tire!!!!!
How does it rev with no load? flat ground? just fishing but if you have fuel and air it must be a haywire signal or signal loss somewhere....how is the battery ground cable connections? wierd stuff happens on these from bum connections why can't they be obvious like a flat tire!!!!!
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From: Mission Viejo, CA
Mike,
I don't know if this will help but I had a similar problem today.
Cruising down the freeway, doing about 72, and the truck began to slow down. I applied more fuel and got nothing. She levelled out at 65 and wouldn't go any faster. The more I slowed down, the lower top speed would be. It was as if there was a governer on the engine. I threw the P0122-TPS low voltage code.
I threw this same code a few weeks ago, but was able to reset the TPS voltage to its correct setting, 0.526 volts. I checked it out this evening and noticed a slight drop in voltage, 0.51, but not as much as I expected. When it went the last time, it had dropped to 0.49.
You may want to check the voltage of your TPS. The correct voltage is printed on a label that is attached to the TPS itself, each one is different. The instructions are on DTT's websit. I hope this helps!
I'll be correcting mine tomorrow, in hopes that it will work, so let me know if you need some pics, etc.
I don't know if this will help but I had a similar problem today.
Cruising down the freeway, doing about 72, and the truck began to slow down. I applied more fuel and got nothing. She levelled out at 65 and wouldn't go any faster. The more I slowed down, the lower top speed would be. It was as if there was a governer on the engine. I threw the P0122-TPS low voltage code.
I threw this same code a few weeks ago, but was able to reset the TPS voltage to its correct setting, 0.526 volts. I checked it out this evening and noticed a slight drop in voltage, 0.51, but not as much as I expected. When it went the last time, it had dropped to 0.49.
You may want to check the voltage of your TPS. The correct voltage is printed on a label that is attached to the TPS itself, each one is different. The instructions are on DTT's websit. I hope this helps!
I'll be correcting mine tomorrow, in hopes that it will work, so let me know if you need some pics, etc.
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From: New Meadows, Idaho
Originally Posted by high country
Are you running a comp? I occasionally get lame acceleration and if I kill the comp it comes back to life. It might pay to check the map and IAT connections, Ya know there was a bunch of guys unpluggung the MAP but they were all running boxes,
How does it rev with no load? flat ground? just fishing but if you have fuel and air it must be a haywire signal or signal loss somewhere....how is the battery ground cable connections? wierd stuff happens on these from bum connections why can't they be obvious like a flat tire!!!!!
How does it rev with no load? flat ground? just fishing but if you have fuel and air it must be a haywire signal or signal loss somewhere....how is the battery ground cable connections? wierd stuff happens on these from bum connections why can't they be obvious like a flat tire!!!!!
Rev in neutral is good and flat ground is fair... I will be heading for my girl friends place this T-Day so it will give me a shot at the grade again to find out we are doing...
I'm starting to think the LP is not getting enough fuel to it under load. I'm looking for a pusher pump kit...
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From: New Meadows, Idaho
Originally Posted by piperca
Mike,
I don't know if this will help but I had a similar problem today.
Cruising down the freeway, doing about 72, and the truck began to slow down. I applied more fuel and got nothing. She levelled out at 65 and wouldn't go any faster. The more I slowed down, the lower top speed would be. It was as if there was a governer on the engine. I threw the P0122-TPS low voltage code.
I threw this same code a few weeks ago, but was able to reset the TPS voltage to its correct setting, 0.526 volts. I checked it out this evening and noticed a slight drop in voltage, 0.51, but not as much as I expected. When it went the last time, it had dropped to 0.49.
You may want to check the voltage of your TPS. The correct voltage is printed on a label that is attached to the TPS itself, each one is different. The instructions are on DTT's websit. I hope this helps!
I'll be correcting mine tomorrow, in hopes that it will work, so let me know if you need some pics, etc.
I don't know if this will help but I had a similar problem today.
Cruising down the freeway, doing about 72, and the truck began to slow down. I applied more fuel and got nothing. She levelled out at 65 and wouldn't go any faster. The more I slowed down, the lower top speed would be. It was as if there was a governer on the engine. I threw the P0122-TPS low voltage code.
I threw this same code a few weeks ago, but was able to reset the TPS voltage to its correct setting, 0.526 volts. I checked it out this evening and noticed a slight drop in voltage, 0.51, but not as much as I expected. When it went the last time, it had dropped to 0.49.
You may want to check the voltage of your TPS. The correct voltage is printed on a label that is attached to the TPS itself, each one is different. The instructions are on DTT's websit. I hope this helps!
I'll be correcting mine tomorrow, in hopes that it will work, so let me know if you need some pics, etc.
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From: Mission Viejo, CA
Thread Starter
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From: New Meadows, Idaho
Originally Posted by piperca