I have a five year old Texas Elite 34 that has been doing wild temperature swings lately.  The modification done to the grill are as follows:

Savannah Stoker V4.0 - added in the first year
Smoke Daddy 2 RPM auger motor - added in the first year
Smoke Daddy heat deflector - added maybe at year three

Smoke Daddy Ceramic Igniter - added a week ago
Smoke Daddy 9 hole burn pot - added a week ago
Smoke Daddy auger motor stabilizer bracket - added a week ago

I started seeing strange things like a flame out around Mother's Day while cooking a brisket at 240 F after wrapping.  The SSV4 has it's OutL set at 15%.  The burn pot only contained only ash after re-ignition failed and a shutdown ran automatically.  I had to drop my son off at a friends so I wasn't around to see it happen but was only gone for 30 minutes.

The recent modifications were made after brisket flame out.  My old 7 hole burn pot had seen better days so I replaced it along with the other two modifications.  I looked up the materials list for my Traeger and it now calls for a 9 hole burn pot.  After the modifications, I tried to set my OutL but started seeing pretty wild temperature swings at low manual feed rates.  At 15% it would rise to 230F and then fall to 180F it would repeat these swings over and over again.  I set the temperature to 225F and let it stabilize for an hour or so and did a re-calibration.  Well it flamed out several times this past weekend while smoking ribs at 190F.

I have pretty much always purchased Traeger pellets at Traeger Costco roadshows. The three bags I'm using now were purchased several month ago when Traeger started up the road shows again.  I am beginning to wonder if something changed in the pellet manufacturing process.  The other possibility is the auger may be binding occasionally.  Has anyone else seen this problem on older pellet grills?

To rule out the pellets, I am going to try some from a different manufacturer.  Lumber Jack used to be hard to find in my area but just saw that Dick's Sporting Goods now carries them.  They have a store a few miles from house and they are in stock.   
     

           

It may be the burn pot not allowing enough air into the fire.  I remember reading about issues with the wrong # of holes in the burn pot causing folks issues like you are describing.

My two cents on the pellets are that Traeger are probably one of the worst in the industry.

The Lumber Jack pellets performed better.  However, the SSV4 is still doing +30F -20F with the set point at 190F.  There was no white smoke or flame outs even with OutL set to 11%.  The other thing I need to check if the pit performs better when shaded.  Very clear skies and 90F plus temperatures are common here.

The burn pot holes are still in question.  I went from a 7 hole to a 9 hole.

 

I did a calibration run last night when it was around 65F outside.  My pit is still having issues with wide temperature swings so I can rule out high daytime temperature and direct sunlight. 

I started thinking about Bar-B-Lew's comment about air flow.  My fan stuck one time last winter I'm guessing from corrosion in damp weather.  I flicked one of the fan blades and it started to run.  It seems my pit is slower reacting to increased pellet loads than what I remember.  I have a spare fan so I'll give that a try tonight. 

 The fan sticking issue for me was lack of lubrication..It would be slow or stuck when cold.  The lack of lubricant is the cause.. I simply applied a low viscosity (thin) full synthetic oil, sparingly to the bushings

 using a needle oiler that disperses very small drops of oil. The best job is done by dismantling the fan motor for better access to the bushings and shaft.. Note:  The motor rotation can be changed by reversing

 the coil polarity therefore note the coil position prior to disassembling if you go that route..

 A properly lubricated motor should offer many years of trouble free service. Most of the new motors are marginally lubed with questionable lubricant.

 The FAN: If the fan is underperforming, turning slowly, damaged blades, or air flow to the fanis restricted, higher temperatures would be more affected than the lower ones.   The Traeger fans have one speed

 = fixed airflow..  The requirement for more air parallels the the combustion rate: more fuel requires more air.

Finally got to the bottom of this.  At set point 225F, the SSV4 could not converge on the set point.  The only thing I haven't changed out was the RTD. 

I setup my Fireboard with two environmental probes.  One probe was set in the middle of the chamber and the other tie wrapped to the RTD.  The center probe measured about 225F when the SSV4 measured 225F and the tier wrapped probe a few degrees lower.  Something interesting was observed after a significant amount of pellets were added after the RTD temperature dropped far below 225F.  The temperature crossed 225F and went to 245F as measured by the RTD.  However, the tie wrapped probe only measured 230F.  The RTD measurement was way off.  My theory is the erroneous high temperature reading prevented the SSV4 from adding more pellets soon enough to avoid a big undershoot.  The big undershoot resulted in a lot of pellets being added to get back to the set point resulting in an overshoot. It kind of explains the inability of the SSV4 to converge on the set point.

I had a new RTD in my parts box and installed it today.  The RTD and tie wrapped probe were within a few degrees of each other and the center probe a few degrees higher.  The setup with the new RTD converged on the 225F set point within in around 30 minutes and stayed around +/- 5F.



 

  BINGO ! Persistence pays off.   Now on with cooking.