Help 24v idling rough.

[Dmann]

So I’ve been having this problem with my truck, it randomly started the other day, when the truck warms up at an idle it sounds likes it missing, when I am driving it and hold it at a steady rpm around 1500 it surges and then when you rev it up, or let off the throttle to while it is in gear it takes a while to idle back down. I already tried to clean the injectors and changed the fuel filter and the water separator. Don’t know what else to do. Anybody know what’s going on?

[Evan]

Giving you a bump.

 

I think a slow rev down might mean its starving for fuel.

Do you know what your fuel pressure is?

[Dmann]

My gauge is reading 16-17 psi, but I’m not sure at the vp. I was gonna go get an actual gauge here in a minute and test it. 

 

I was talking to a shop down here and he told me to reset my valve lash but I can’t really see how that would effect it this bad. But I am gonna try that also if I’m getting good pressure at the vp. 

[Bullet]

I don't know what year truck you have...but it sounds like it could be the TPS or APPS depending on what year truck you have...or a bad VP.  Have you checked for any codes?  That will usually tell you which way to look. 

[dripley]

8 hours ago, Dmann said:

My gauge is reading 16-17 psi, but I’m not sure at the vp. I was gonna go get an actual gauge here in a minute and test it. 

 

I was talking to a shop down here and he told me to reset my valve lash but I can’t really see how that would effect it this bad. But I am gonna try that also if I’m getting good pressure at the vp. 

I guess I am trying to understand your fuel pressure. You say your gauge is reading 16 to 17 psi but not sure at the VP. If your gauge is after your last filter thats the pressure the VP is seeing. Is your FP gauge not an actual pressure gauge? Not sure what that means.

 

Codes are important if you have any. If you you dont have a scanner most any auto parts store has them and will be happy to read them for you. Jot them down and post them up. It will help.

 

As far as the APPS vs TPS they are the same. The APPS mounts on the accelarator pedal and the TPS on our trucks mounts to the bellcrank assembly on the intake manifold. They both perform the same function. The APPS started on the 3rd gens I believe.

[dave110]

I always thought the 2nd gen had an APPS

51 minutes ago, dripley said:

As far as the APPS vs TPS they are the same. The APPS mounts on the accelarator pedal and the TPS on our trucks mounts to the bellcrank assembly on the intake manifold. They both perform the same function. The APPS started on the 3rd gens I believe.

I always thought the 2nd gen had an APPS?

[Dmann]

4 hours ago, Bullet said:

I don't know what year truck you have...but it sounds like it could be the TPS or APPS depending on what year truck you have...or a bad VP.  Have you checked for any codes?  That will usually tell you which way to look. 

The truck is a 2001 with a 6 speed don’t know if that matters. I am running the codes now to see what they say

1 hour ago, dripley said:

I guess I am trying to understand your fuel pressure. You say your gauge is reading 16 to 17 psi but not sure at the VP. If your gauge is after your last filter thats the pressure the VP is seeing. Is your FP gauge not an actual pressure gauge? Not sure what that means.

 

Codes are important if you have any. If you you dont have a scanner most any auto parts store has them and will be happy to read them for you. Jot them down and post them up. It will help.

 

As far as the APPS vs TPS they are the same. The APPS mounts on the accelarator pedal and the TPS on our trucks mounts to the bellcrank assembly on the intake manifold. They both perform the same function. The APPS started on the 3rd gens I believe.

What I meant by the fuel pressure was my pillar gauge reads 16-17 depending how hard I’m in it, but it’s hooked up to the air dog after the filters though. 

 

And i I have to codes coming up on the scanner and none in the key trick. 

[dripley]

10 minutes ago, dave110 said:

I always thought the 2nd gen had an APPS

How I see it.

APPS=acclerator pedal position sensor. 

TPS=throtle positioning sensor

 

APPS is on the the pedal, TPS is on the engine. That being said they both do the same thing, it is just location and how each individual sees it. They might be configured different for the location but do the same thing. 

 

After taking mine apart and really seeing it had no mechanical connection to the engine I was a bit surprised. Seems to me dodge was tring to fake us out like the fake oil pressure gauge in the 02's and later years.

44 minutes ago, Dmann said:

 

What I meant by the fuel pressure was my pillar gauge reads 16-17 depending how hard I’m in it, but it’s hooked up to the air dog after the filters though. 

 

And i I have to codes coming up on the scanner and none in the key trick. 

I have an AD also and it shoul be giving you accurate pressure as long as the gauge is good.

 

What codes are you seeing?

[Dmann]

7 hours ago, dripley said:

How I see it.

APPS=acclerator pedal position sensor. 

TPS=throtle positioning sensor

 

APPS is on the the pedal, TPS is on the engine. That being said they both do the same thing, it is just location and how each individual sees it. They might be configured different for the location but do the same thing. 

 

After taking mine apart and really seeing it had no mechanical connection to the engine I was a bit surprised. Seems to me dodge was tring to fake us out like the fake oil pressure gauge in the 02's and later years.

I have an AD also and it shoul be giving you accurate pressure as long as the gauge is good.

 

What codes are you seeing?

I’m not getting any codes what so ever. On the scanner or the key trick. The last post I made when it said “I have to” must have got autocorrected because I meant to put “I have no” sorry should of double checked before I posted. 

Edited September 5, 2019 by Dmann

[Dmann]

I just found out that I have a fuel leak but it’s on the return line on the sending unit. Would that cause my problems? In my mind I don’t see it because the supply still have the pressure it needs. But what do y’all think?

[dripley]

Not sure what you mean by the return line on the sending unit.

[Dmann]

1 hour ago, dripley said:

Not sure what you mean by the return line on the sending unit.

The fuel return line that come from the back of the block and goes to the pump in the tank with a quick disconnect is leaking. 

[KATOOM]

It sounds like the APPS.  Check its voltage or replace it.

[dave110]

1 hour ago, Dmann said:

The fuel return line that come from the back of the block and goes to the pump in the tank with a quick disconnect is leaking. 

The one on the back of the head. It has 2 rubberized banjo bolt washers that can be bought from Geno's Garage among other places. It is not terribly hard to replace them. Gotta lay down on the valve cover and act like you're hugging the engine. A mirror would help you to see, but you can feel your way around. Takes a 17mm wrench IIRC. and only like 17 ft lbs. Don't over tighten. I would do like said above though and check/ replace the APPS, the one on the engine . Get a Timbo if you do. A lot less money and more reliable. We sell them in the forum store but I see we are stocked out at the moment.

[dripley]

A leaky return line us not the problem. 

[JAG1]

Like Dave110 says, you need to get the Timbo if you are wanting to keep and build a good truck. It's less than half the cost of the OEM and more reliable.

Do you still have the intank pump hooked up down in the tank with the AirDog pulling fuel thru it? Even screens in the tank can clog slow down the flow.

[Mopar1973Man]

 

On 9/2/2019 at 7:46 PM, Dmann said:

it randomly started the other day, when the truck warms up at an idle it sounds likes it missing,

 

Sign of wore out injectors. How many miles on the truck?

Edited September 6, 2019 by Mopar1973Man

[Dmann]

23 minutes ago, Mopar1973Man said:

 

 

Sign of wore out injectors. How many miles on the truck?

The truck has 303xxx but I rebuilt the motor at 300770 with new injectors. 

[Mopar1973Man]

Still it could be the pop pressure is too low. @pepsi71ocean only had 28k miles on his injectors and they dropped to 260 bar and the minimum is 293 bar. I've had a set barely last 7k miles and had a injector that drop pop pressure and created a miss too. It's possibly. You could pull them out and send them to DAP and they will test them for you. 

[KATOOM]

On 9/2/2019 at 6:46 PM, Dmann said:

So I’ve been having this problem with my truck, it randomly started the other day, when the truck warms up at an idle it sounds likes it missing, when I am driving it and hold it at a steady rpm around 1500 it surges and then when you rev it up, or let off the throttle to while it is in gear it takes a while to idle back down. I already tried to clean the injectors and changed the fuel filter and the water separator. Don’t know what else to do. Anybody know what’s going on?

 

This is not what injectors sound like...^

 

I'd check the APPS way before tearing the injectors out and having them pop tested.