[Flemster]

Having a really sporadic and wild issue with my Duramax as of recently. The truck has 204k with pretty great maintenance.

This issue has been pretty intermittent over the last 2500 miles or so. Below is a video of what is going on, this instance is about the worst it gets but when towing it is violent to say the least. First happened a month ago and while towing about 12k pounds. Happened a few times on the trip but never threw a code. Choked it up to be a fuel line pinching and decided to install a lift pump per recommendations from a shop I chatted with.

The truck basically falls on its face for a 1/4 second. Sometimes one quick one, sometimes 2 or 3 times, and when it's really bad the doors all lock.

3 weeks go by with a lift pump, no issue. Drive 500 miles up to Montana with almost no issues until the last 45 minutes. Exact thing shown in the video. A few minor ones after. Some going fast some stuff 10 mph on a dirt road.
On the way home, it happened about 10-15 times. Runs perfectly fine in between, maybe a bit low on power but I was in a headwind and babying it at this point.

Code thrown is po336 Crankshaft Position Sensor.

My thoughts are leaning towards the wiring issue instead of fuel or the Crankshaft position sensor actually being wrong. Along with this the doors sometimes lock and as of very recently, my blower motor is stuck in one speed and also does not turn off with the truck even with the key out of the ignition.

I already ordered a new blower motor resistor to see if that fixes that issue and will update on that shortly. Today I plan to give it the old ford shakedown test and let the truck idle and shake all my wiring to see if it gets anything to stutter or do weird things. Chase all the wiring especially to the CSP. I will update on that shortly too.

Also, had about 40 miles of range left, was doing this regardless of how much fuel I had so do not pay too much attention to the low fuel. Truck was getting around 17.5-19 mpg the whole trip with 1500 pound slide in camper on.

I have a straight pipe, AFE intake, Edge Juice with Attitude on the 1st tune "Milage". May also try unplugging the Juice as I have heard they can cause some wacky shit.

Any ideas appreciated.

Click to watch.

 

[ChevyTech77]

Fix the wiring issue that’s causing your blower fan to act up first. Resistor won’t fix it.

 

[Flemster]

Do you think it is related?

 

[Flemster]

Fix the wiring issue that’s causing your blower fan to act up first. Resistor won’t fix it.

Do you think the issue is related?

 

[ChevyTech77]

Do you think the issue is related?

Well, if it all showed up around the same time? Yes.

 

[d9er]

Yes without a doubt throw that EDGE WITH JUICE out the freaking window and be done with it. I had one when i first got my lbz EDGE would not stand behind it. All my problems went away you have to take it out of line not turn it to stock setting's

 

[Flemster]

Yes without a doubt throw that EDGE WITH JUICE out the freaking window and be done with it. I had one when i first got my lbz EDGE would not stand behind it. All my problems went away you have to take it out of line not turn it to stock setting's

I took it off tonight, checked all my wiring to no avail, and have a new resistor for the blower motor on the way. I'll update once all this is done. I have a 1,000-mile trip in early July so hopefully, it's not stuttering the whole way there and back. Scares me when pulling out into traffic, don't want it to fall on its face. Thankfully only pulling a 4k trailer for this one. Drove it around a bit tonight and performed totally normal but being it would sometimes happen every 10 minutes or after 2 hours I can't be sure yet.

 

[Ron Nielson]

Assuming you still have P0336, your problem could be the CKP sensor or its circuit. See attached.

 

[knotReally]

These guys know what they are talking about..
i'd recommend checking fuses. Its free easy and eliminates a potential DOH! put your multimeter to continuity test setting and probe away.

 

[Flemster]

Update.

I replaced my blower motor resistor and pulled/cleaned my blower motor. The blower motor was filled with dust and crap (used to have a vibration on highest setting) once cleaned and all hooked back up my blower motor issue was fixed. The new resistor fixed that issue and it also no longer vibrates now that it's cleaned (tested it before cleaning and it still vibrated).

Replaced my resistor with this one as per a recommendation on a youtube video. https://www.amazon.com/dp/B078J3B4S8?psc=1&ref=ppx_yo2_dt_b_product_details

It does require some simple cut and splice of 3 wires but super easy to do, took me 20 minutes.

I have driven about 50 miles and no stutters or surges without the Edge hooked up. I also took the time to tape up and clean up any of the old wiring looms that had become brittle and fell off. This may have helped, but makes the engine bay look cleaner non-the-less.

I will update again after I put more miles on it and can say for sure if it's gone. Bummed to lose all the monitoring the Edge provides but have a Scan Guage II on the way and may install some pillar gauges for EGT and Boost Pressure.

If anyone wants an old Edge Juice with Attitude I'll be selling one here soon if my problems sorted!

 

[Jack skellington]

Just get you the plain edge cst 3 if you want to monitor i love mine and then get with a good tune company and tune it

 

[darmah59]

Having a really sporadic and wild issue with my Duramax as of recently. The truck has 204k with pretty great maintenance.

This issue has been pretty intermittent over the last 2500 miles or so. Below is a video of what is going on, this instance is about the worst it gets but when towing it is violent to say the least. First happened a month ago and while towing about 12k pounds. Happened a few times on the trip but never threw a code. Choked it up to be a fuel line pinching and decided to install a lift pump per recommendations from a shop I chatted with.

The truck basically falls on its face for a 1/4 second. Sometimes one quick one, sometimes 2 or 3 times, and when it's really bad the doors all lock.

3 weeks go by with a lift pump, no issue. Drive 500 miles up to Montana with almost no issues until the last 45 minutes. Exact thing shown in the video. A few minor ones after. Some going fast some stuff 10 mph on a dirt road.
On the way home, it happened about 10-15 times. Runs perfectly fine in between, maybe a bit low on power but I was in a headwind and babying it at this point.

Code thrown is po336 Crankshaft Position Sensor.

My thoughts are leaning towards the wiring issue instead of fuel or the Crankshaft position sensor actually being wrong. Along with this the doors sometimes lock and as of very recently, my blower motor is stuck in one speed and also does not turn off with the truck even with the key out of the ignition.

I already ordered a new blower motor resistor to see if that fixes that issue and will update on that shortly. Today I plan to give it the old ford shakedown test and let the truck idle and shake all my wiring to see if it gets anything to stutter or do weird things. Chase all the wiring especially to the CSP. I will update on that shortly too.

Also, had about 40 miles of range left, was doing this regardless of how much fuel I had so do not pay too much attention to the low fuel. Truck was getting around 17.5-19 mpg the whole trip with 1500 pound slide in camper on.

I have a straight pipe, AFE intake, Edge Juice with Attitude on the 1st tune "Milage". May also try unplugging the Juice as I have heard they can cause some wacky shit.

Any ideas appreciated.

Click to watch.

Electrical issues are the worse. The blower operating when ignition off is a big one, must be a short someplace need to track that down. Also there is a common earth on the frame just under the driver door that tends to get corroded and cause all sorts of weird things.

 

[Flemster]

So far, a new resistor for the blower motor and unplugging the tuner have been the trick. I have a new fuel filter to swap in but haven't yet as its only got like 4,000 miles on it with a lift pump as well so it's now a secondary filter.

I trailered a 4k pound deck over all weekend moving stuff back and forth between my old and new house. Probably 150 miles total since pulling stuff apart no problems so far.

 

[Bsimster]

Glad to read it was fairly simple fix! Keep us updated

 

[Flemster]

I have done about 3,000 miles since and 1500 of those miles grossing about 20k. Happy to report the shuttering is gone. I would put it all on the Edge Juice. I will say without the tune the truck does run a good bit hotter towing heavy so I'll probably be looking into getting a good tune on the truck again in the future.

 

[Flemster]

Here's a picture of the rig because people like pictures.

.