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low power and trouble rev'ing


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Hi guys,

Concerning my truck below in my signature.....When driving the truck in any Edge tune, the truck is hard to rev above 2000 rpms.  This is while driving normal and not hotrodding the truck.  If I floor the truck, sure it will rev up beyond 2000rpm, but during normal driving the truck accelerates nicely until 2000rpm then just falls on it's face while maintaining my pedal position.  This is even more noticable while towing a trailer.  It's hard to get my rpm's up to grab the next gear. 

 

I have experimented with all Edge tunes and doesn't seem to matter.  My boost appears to be fine.  EGT's are good.  BTW, i am only getting 16mpg highway or city. 

 

Time for injectors??

 

Thoughts?

 

Thanks.

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Thank you.  I'll check all the Edge connectors.  Then try removing it. 

 

Fuel pressure is a constant 15-16psi.  Fuel filters were just changed 3000 miles ago.  I really don't drive this truck that much (I have a company vehicle). 

 

Bad fuel:  this has been going on for a long time.  A year or so. 

 

I'll scan for codes tonight. 

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I didn't get a chance to scan for codes last night.  I did calibrate my pedal last time I had the batteries disconnected. 

 

I do NOT have a noise filter on the PCM.  Do you have a write up on this? 

 

APPS is a good thought.  I'll look up Michael's write up and test this weekend. 

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  • Owner

I didn't get a chance to scan for codes last night.  I did calibrate my pedal last time I had the batteries disconnected. 

 

I do NOT have a noise filter on the PCM.  Do you have a write up on this? 

 

APPS is a good thought.  I'll look up Michael's write up and test this weekend. 

 

No. Because you good the way your are without noise filter. Do NOT add extra grounds, tin foil or noise filters these are all band-aids to bigger issues and just cover up the problem but never fix it.

 

You can try the APPS sensor but I would check charging AC voltage too. Typically I don't start suggesting parts till some diagnostics are done.

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Oh okay good.  Thank you.  I thought it was something I needed.

 

I don't know if this is important or not, but after traveling for awhile, when I come to a red light, my truck will idle at 900rpm.  It take several seconds for it to idle down to 825 or so. 

 

Any recommendations or write up on checking the charging system?  Thanks for your patience.  Vehicle electrical is not my strong suit.

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 if you haven't already please check your ground wires and Terminal connections. IM not saying ADD grounds for no reason 'BUT" WIRES are just like us they don't last forever. They become chafed, cut, mangled and corroded . its good to visually inspected your grounds from time to time especially if you live in areas where road salt is used. i spray dialectic grease on mine every so often especially the ones on drivers side in front of battery,  and i do also battery terminals. I would only replace a ground wire if i found one bad or one that was questionable. Like Mike said, there is no sense add grounds only if one is bad

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No DTC were detected.  All terminals and positive and negative cables checked out good. 

I also reseated all the Edge connectors.  I test drove and no change.  I'll try to bypass the Edge tomorrow. 

 

Do I now check APPS voltage per Michael's write up "Stock APPS Sensor Voltage Adjustment test"?

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  • Owner

No don't do that. Stock APPS have been pre-set and don't have any value of voltage that you can really test for. But you can take a analog volt mater and pan the scale of the APPS sensor looking for a sudden drop or surge in voltage.

 

As for Grounds to worry about is the battery cables. That's it. The other body grounds are just secondary stuff. Lights, horn, etc. The ECM, PCM and VP44 are all ground to the battery directly and don't have any body ground connection.

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No don't do that. Stock APPS have been pre-set and don't have any value of voltage that you can really test for. But you can take a analog volt mater and pan the scale of the APPS sensor looking for a sudden drop or surge in voltage.

 

As for Grounds to worry about is the battery cables. That's it. The other body grounds are just secondary stuff. Lights, horn, etc. The ECM, PCM and VP44 are all ground to the battery directly and don't have any body ground connection.

 

I thought the ECM grounded through the motor block, and isn't there a ground wire behind the starter as i recall that jumpers to frame or maybe its the negative post on the starter :think:  :think:

and i think there is a GND on front bottom of engine that jumps over to the Frame

Edited by rburks
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  • Owner

No. ECM, PCM and VP44 have no body connection. Take a look at the wiring diagram. G115 is the actual battery cable on the passenger side. As for the block ground that is lift pump and fuel heater hidden behind the starter. Again a secondary system it will use body ground but primary system like all the computers they use the actual battery cable. Now take notice to the fuel pump relay in the upper right corner it uses a body ground G102 and it states its location (left side fender shield).

 

2002-Dodge-Wiring-pg3.jpg

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No. ECM, PCM and VP44 have no body connection. Take a look at the wiring diagram. G115 is the actual battery cable on the passenger side. As for the block ground that is lift pump and fuel heater hidden behind the starter. Again a secondary system it will use body ground but primary system like all the computers they use the actual battery cable. Now take notice to the fuel pump relay in the upper right corner it uses a body ground G102 and it states its location (left side fender shield).

 

 

:stuned:  :think: wait, i don't think so, look at your print above. bottom right;  see the black/tan G115 PRIMARY BATTERY BODY GROUND   WHICH "T's into black/tan Z12  GROUND CIRCUIT to ECM AND S168 GROUND CIRCUIT TO VP44 INJECTION PUMP.. What am i missing :shrug:

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there are several ground wires that run and connect via terminal lug ends, to the stud on inner fender in front of battery on drivers side and grounded thru battery by a wire off of - negative post. at least thats how my truck is, i have had to replace a few of the terminal ends in the past

 

VP, APPS, ECM, AND GRID HEATERS, all ground thru this

Edited by rburks
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G115 actually connects to the passenger side battery cable. Look at the passenger side cable there is a smaller cable off the post with a clip connector and it will run into the loom near the PCM. This is the main ground for those devices. Again it does not attach to body. Now the main cable does indeed attach to the block and the body.

 

Here is the G115 connector.

post-1-0-94580000-1433598273_thumb.jpg

 

Here is the path alone the orifice tube into the loom for G115.

post-1-0-35626000-1433598217_thumb.jpg

 

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G115 actually connects to the passenger side battery cable. Look at the passenger side cable there is a smaller cable off the post with a clip connector and it will run into the loom near the PCM. This is the main ground for those devices. Again it does not attach to body. Now the main cable does indeed attach to the block and the body.

 

Here is the G115 connector.

attachicon.gifDSCF3068.JPG

 

Here is the path alone the orifice tube into the loom for G115.

attachicon.gifDSCF3069.JPG

 

THERE ARE two only wires coming from the negative battery terminal on drivers side of my truck, one goes to the stud post on the inner fender in front of battery and the other goes to the frame. blk/tan wire come out of ecm harness and also bot to frame, so i GUESS you can say its connected to -Neg side of Battery just i connected thru frame :shrug:

  also main negitive battery cable on passenger side goes straight to engine block....and smaller one coming from  - terminal goes to side post on inner fender behind air filter

 

  I'm trying to get pictures posted if i can  

Edited by rburks
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