Engine runs rough

Tiny
MATTHEW0811
  • MEMBER
  • 1999 DODGE RAM
  • 125,000 MILES
I have a 99 dodge ram 2500 v10 4wd I have changed idle air sensor. Complete tune up coils wires and plugs I changed drive o2 sensor cause light was on but truck still runs rough like it has a misfire on a cylinder. Here's what it does when at idle it kinda pops in the exhaust like it has a miss or loading up on fuel you can rev motor a couple of times and it clears up when u rev motor u can smell a hint of fuel. If I sit at a red light and go to take off it starts to sputter with very low power if u ride it out and listen u can hear it popping in the exhaust like a backfire but when it clears you get massive power quick and then its fine till next red light. If you drive truck on interstate your fine no problems hits passing gear fine. Im stumped can anyone help please
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Wednesday, August 15th, 2012 AT 1:38 AM

44 Replies

Tiny
ASEMASTER6371
  • EXPERT
Start with a compression test. Once that is done, make sure you have the wires on correctly. It is easy to cross them.

What was the codes? When did this start?

Roy
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Wednesday, August 15th, 2012 AT 2:32 AM
Tiny
MATTHEW0811
  • MEMBER
I have done compression. All cyclindrs r over 100 wires aren't crossed I've double checked myself thing so
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Wednesday, August 15th, 2012 AT 4:31 AM
Tiny
MATTHEW0811
  • MEMBER
Code was lean o2 bank 1 sensor 1 And been doing this for about a month just started out of nowhere
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Wednesday, August 15th, 2012 AT 4:33 AM
Tiny
MATTHEW0811
  • MEMBER
02 sensor was extremely black when replaced truck started smoking black when o2 sensor light came on so replaced 02 and stopped smoking now just acts like a misfire. Only would smoke under heAvy throttle or towing
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Wednesday, August 15th, 2012 AT 4:35 AM
Tiny
ASEMASTER6371
  • EXPERT
Do you have access to a scan tool?? you need to monitor the long term trims on the o2 sensors to see what is happening.

This guide can help

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

Roy
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Wednesday, August 15th, 2012 AT 12:29 PM
Tiny
MATTHEW0811
  • MEMBER
No I do not have access to a scan tool
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Wednesday, August 15th, 2012 AT 12:33 PM
Tiny
MATTHEW0811
  • MEMBER
What about a injector problem not allowing injector or injectors to fully close and loading up on fuel? Just a thought.
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Thursday, August 16th, 2012 AT 2:34 AM
Tiny
LAWNGUY0321
  • MEMBER
Did you figure out the problem I have a 98 that does the exact same thing please let me know thx
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Saturday, September 29th, 2012 AT 2:45 AM
Tiny
CRAZYCHICK
  • MEMBER
I had this problem it has the #3 fuel injector has bad allowing fuel into the engine got a new one for $76.00 all fixed FYI
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Monday, October 8th, 2018 AT 10:53 AM
Tiny
PATTERSON4127
  • MEMBER
  • 1999 DODGE RAM
Electrical problem
1999 Dodge Ram V8 Four Wheel Drive Automatic alot miles

I put a 2000 or 2001 motor in my 99 ram1500. I had to change out the injecter plugs because the injecters on the new motor had different plugs. It would start but it ran rough. I ran a scan and it said that the timing was 3 deg. Off, so I fixed that and now it will start and idle fine but when you put it in gear and try to drive it it starts popping and missing and running rough. I have ran several more scans but they dont show anything or give me any codes.
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Monday, October 8th, 2018 AT 10:54 AM (Merged)
Tiny
JACOBANDNICKOLAS
  • EXPERT
We always recommend staying with a direct replacement because this always seems to happen. The only thing I can add is to make sure the sensors are all correct and hooked up. Also, make sure there are no vacuum leaks.

Let me know what you find.
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Monday, October 8th, 2018 AT 10:54 AM (Merged)
Tiny
JP3966
  • MEMBER
  • 1999 DODGE RAM
  • V8
  • 4WD
  • AUTOMATIC
  • 35,000 MILES
I have a 1999 dodge ram 2500 that starts to run rough when it gets up to temp. It runs fine on short trips and before it gets up to temp. Just did a tune up with no help any sugestions?
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Monday, October 8th, 2018 AT 10:54 AM (Merged)
Tiny
JACOBANDNICKOLAS
  • EXPERT
Hi:
Is the check engine light on? Even if it's off, I would take the truck to a nationally recognized parts store and have them scannt he computer for codes. It's usually free to have done and it may point us in the right direction.

Also, does the truck seem to run rich or any other things you can tell me?

Joe
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Monday, October 8th, 2018 AT 10:54 AM (Merged)
Tiny
VINCARTHUR
  • MEMBER
  • 1999 DODGE RAM
  • V8
  • 2WD
  • AUTOMATIC
  • 189,000 MILES
My dodge sudenly stopped after giving no indication of a problem. After I got it home, I checked all sensors and ran a diagnostic with a scan tool--nothing! I checked timing, spark, and fuel pressure all OK. After changing plugs, they were fouled with black soot, the motor ran good for a moment and then died. I removed some fuel from at injector fuel rail and noticed that it looked yellowish. It looks alot like old fuel that you see in a lawn mower thats been sitting for several years. I have never experianced bad gas before and am not sure if it is. I filled up at the station and drove almost half a tank out before my engine quit. Could this be bad fuel or something else?
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Monday, October 8th, 2018 AT 10:54 AM (Merged)
Tiny
JACOBANDNICKOLAS
  • EXPERT
Does the fuel have a strange odor to it?
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Monday, October 8th, 2018 AT 10:54 AM (Merged)
Tiny
VINCARTHUR
  • MEMBER
After rechecking the fuel, It looks like it may be ok. The yellow color was coming from contamination in the hoes I was using. One thing I have noticed is the fuel pressure bounces around erratically, between 35-50 psi, when the motor is turning over and also when it finally does idol for a little while. I am thinking it may be the fuel pressure regulator or maybe EGR valve--not real sure.
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Monday, October 8th, 2018 AT 10:54 AM (Merged)
Tiny
JACOBANDNICKOLAS
  • EXPERT
When you checked the pressure, did you disconnect the regulator to see what happened? If so, how did the pressure react? Based on what you are saying, it does sound like a bad regulator.

Here is a HOW TO for checking fuel pressure and the regulator. Try it and let me know what you find with the regulator.

http://www.2carpros.com/how_to/how_to_check_fuel_pressure.htm

Let me know what you find.
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Monday, October 8th, 2018 AT 10:54 AM (Merged)
Tiny
VINCARTHUR
  • MEMBER
I watched the video on testing the regulator but the regulator on this vehicle is a "returnless" fuel system, according to the Hanes manual. The regulator is mounted on top of the fuel pump sending unit at the tank. I am not sure how to test this one. Another tid-bit of info, yesterday when I finally got the engine to run, roughly however, my engine suddenly smoothed out and idled correctly, I was able to give a little throttle without stalling the motor out; during this time I watched my pressure gauge and noticed that it was holding a steady pressure and not bouncing around. This only lasted for about 60 seconds and then went back to rough idle and pressure gauge bouncing around erratically.
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Monday, October 8th, 2018 AT 10:54 AM (Merged)
Tiny
JACOBANDNICKOLAS
  • EXPERT
I'm sorry!!! you are correct. THis has the regulator mounted at the top of the fuel tank. It's a combination filter and pressure regulator. The regulator is a mechanical device not controlled by the PCM or engine vacuum. It's calibrated to maintain a pressure a pressure of about 49 psi at the fuel injectors. The unit contains a diaphragm, calibrated springs and a return valve.

Chances are that is the problem. Here are the directions to replace it:

REMOVAL & INSTALLATION

Disconnect the negative battery cable.
Remove the fuel tank filler cap.
Properly relieve the fuel system pressure.
Raise and safely support the vehicle.
Remove the fuel tank assembly.
The fuel pressure filter/regulator assembly is located on the top of the fuel pump assembly. It is not necessary to remove the fuel pump to remove the pressure filter/regulator assembly. Matchmark the direction the hose fitting points. Unit must be reinstalled pointing in the same direction.
Twist the filter/regulator assembly out of its grommet on the fuel pump.
Remove the snap ring that retains the convoluted tube to the filter/regulator. Slide the tube down the plastic fuel tube to access the fuel tube clamp.
Gently cut the old fuel tube clamp off, taking care NOT to damage the fuel tube or drop the clamp inside the tank.
Remove the fuel tube from the filter/regulator assembly by gently pulling downward.
Remove the filter/regulator assembly from the fuel pump module.

To install:

Install a new clamp over the plastic fuel tube.
Install the filter/regulator assembly to the fuel tube. Rotate the filter/regulator until it is pointed to line up with the matchmark previously made.
Tighten the clamp to fuel line using Hose Clamp Pliers C-4124 or equivalent.
Slide the convoluted plastic tube up to the bottom of the filter/regulator and install the snap ring.
Press the filter/regulator assembly into the rubber grommet making sure it is pointed in the 10 o'clock position.
Install the fuel tank.
Lower the vehicle.
Connect the negative battery cable.
Install the fuel filler cap.

Here is a picture of the regulator:


http://www.2carpros.com/forum/automotive_pictures/249084_pressure_regulator_1.jpg



According to what I have read, the regulator isn't serviceable. The pump should be regulated to aprox 49 PSI. If it is more than that, chances are the regulator is bad and the pump is good. If it is droping below that, both should be replaced.

Let me know what you find. If I recall, you were droping into the 30PSI range. If you remove the tank, replace both with the filter too.

Joe

LEt me know if this helps.
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Monday, October 8th, 2018 AT 10:54 AM (Merged)
Tiny
BIKERBOYS21
  • MEMBER
  • 1999 DODGE RAM
  • V8
  • 2WD
  • AUTOMATIC
  • 106,000 MILES
I have a Dodge Ram 1500 5.2L V8. Recently my check engine light has come on but the vehicle has been running fine until about a week ago and suddenly when I get into high gears the dashboard will start shaking and the vehicle will start reducing speed. When I take the overdrive off it doesn't run as rough but is still not working properly, what is wrong?
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Monday, October 8th, 2018 AT 10:54 AM (Merged)

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