2006 peterbilt 379 with acert motor having power issues

A dirt lot is not a very good place to be opening up the valve covers, the over head is adjusting the valves and injectors, has to be done periodically to keep it running correctly. Like I said earlier with your lack off confidence in the previous owners I would do both at the same time(overhead and harness), at least you would know what it is not. By your own admission you don't have much experience working on diesel engines, I would at the very least try to find a video on youtube or something so you can see what your getting into before you try anything. It's not exactly the same as adjusting the valves on a gas pick-up. GrapeApe is correct go ahead and get the parts now even if you don't need them now you will shortly, that is my reasoning behind doing the harness while your doing the overhead, your already there (labor-wise) might as well do it while your there, no point in doing it twice (or paying someone to do it twice).

 

X2 on that pressure sensor not cutting down on the power. You will get the check engine light, but no loss of power. I did remove sensor & change the o-ring in hopes to eliminate code flash. I also ran jumper wires over top of valve cover to that sensor from the ECM because the outer harness tends to get toasted also. I don't like buying replacement parts that I did not need.

 

Where in ND are you ? I run out of Newtown and if we are close I can help you.. I know my way around an Acert pretty well.I have had same issues ( code 95) in past. could be a number of things but it's an easy fix
all else fails there is a really good Cat shop in Tioga. PM me for shop info

 

It will derate your motor since the ecm needs to see it working for the IVa system to operate!!!

 

I have run with the pigtail disconnected, with the IVA disconnected under the valve cover, and my Acert has never lost power. I have run it with the pressure solenoid, the diverter valve, temp sensors etc all unplugged @ one time or another when chasing down electrical problem. The only time is acted all nutso was w/a code 72. Which, naturally the fuel was cutting out. Granted all setups are different. It will give a hiccup with the actuator unplugged @ lower speed, yes, but to say it won't pull as normal, not on my motor. I run that Cat w/ a failing harness and it just kept on going. It' a CAT. Would trade it only for another CAT.

 

How much boost did you have when you were unplugging all that stuff???

 

Around 15lbs on the flat, 35-40 climbing a normal 3-4% grade. It did give a hiccup type intermittent pause between 40-50 mph during the actuator disconnect. Chasing a code 92. The only thing that ever anchored her was that injector harness. Even then I drove it another 2100 miles to the house. I would suggest, if the OP is going to stay w the truck, go get a CAT Acert manual from CAT. It'll have MXS,NXS & BSX info. It has everything your going to need as far as schematics. Just get a decent volt meter.

 

It will still run in derate mode and you won't notice anything other than a lack of power and boost. When mine would derate from bad iva's and when that sensor went bad it went from 45+ lbs down to 30-35 in derate mode.

 

I have directly experienced this 3 times and it did not derate.