I'm having issues with my PSD, would a misfire on cylinder 4 cause underboost condition?

 

I moved this down to the 6.0 forum. They should be able to help.

Welcome to FTE. Give them a little time to respond.

 

A single missfire will not noticeably affect boost.
PO272 and 304 are related to the missfire.
Po299 is related to turbo performance which is your problem. You have a sticking dirty turbo or vgt valve or bad/plugged ebp sensor.
PO672 is a #2 glow plug problem.
Find and fix your turbo problem will take care of the underboost.

 

Thank you dannyboy, I'm going to buy an injector or two, some glow plugs. The I will have to take apart the turbo to inspect/clean it. Other than that the truck runs good low end performance is terible right now as well as fuel mileage..


How much boost should I be seeing on a stock PSD 6.0 and at what RPM
RIght now I am seeing 18 to 20psi on factory gauge around 2200rpm or so and higher than that it sounds like engine is on all motor

 

Before you start spending money there is a plug opposite the vgt solenoid that you can unscrew and observe the movement of the vgt rocker assembly that turns the unison ring. A slow jerky movement thru it's range can indicate a dirty turbo or a sticking vgt.

An injector missfire can be caused by bad connection or corrosion of the wires to that cylinder from the ficm or just stiction in that injector.
Check/test before spending is my motto.

 

Check for wiring harness chafing on the #4 cylinder and harness. Double check the connector is seated correctly.

The P0299 has a host of issues that can cause that particular code, some of which have nothing to do with the turbo like low ICP.

Digital gauges would pinpoint the P0299.

Josh

 

That's a good idea. Tomorrow is a holiday so I'll take some time to troubleshoot. Does anyone have a wiring diagram or fsm

 

OK got a chance to mess with the truck à bit. While cold I removed the injector plugs and checked for chaffing and shorts with a multimeter. Didn't see anything odd. Checked the resistance on injector 2 and 4 got 0.8ohm on closed coil and open coil on each injector while cold.

Then I let it do the ignition on buzz. You can actually feel the injector plugs ticking away but on number 2 all its doing is intermittent ticks , like for instance inj 2 goes tick tick tick tick tick tick tick inj 4 goes tick..............tick. ........ tick

Second thing I did was take plug 2 and put on injector 4 same result intermittent or slower ticks than the others.

Also measured the voltage going to injectors engine off truck hadnt been started since Friday. Recorded 36v

 

Your next step should be to check the ficm voltage. 36v at the injector is 12v to low.

 

Yeah, thats what I was thinking, this isnt good. Don't want this ting to die on me.

 

That was a good idea to manually check the spools. Nice job!

Josh

 

Looks like I'm going to need a ficm, injector and glow plugs on the driver side just to give peace of mind.

 

OK people I've replaced number 4 injector and the truck is running like a charm. However I have that code P0672 to deal with that's not really a big issue for me. P0299 is the one that I'm weary about. I've looked for leaks with no obvious leaks spotted.
Don't want to take turbo off and find I need parts unison ring etc is it a good idea to get another turbo then rebuild mine that way I'm not down for more than a few hrs