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Low Boost Pressure

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Hitman

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I have a 2022 Ram 2500 6.7 Cummins, It has been deleted with no HP increase above stock. The engine runs great when unloaded, if I accelerate quickly the turbo boost will go to the 12-14 range with no issues. The engine performs perfectly when using the exhaust brake. When towing my 13,000 pound camper it runs great and pulls like a train until I go up a steep hill. The engine will stop pulling for maybe a second and then resume pulling with reduced power. I finally monitored the boost pressure while pulling the camper, the engine pulls great, but when the boost gets to about 22psi or so is when the engine stops pulling for a second or so and then resumes pulling at reduced power and the max boost I see is 8-9psi. When I stop and turn the engine off and restart it to resume my trip the engine runs great again with the boost able to go back to 22psi at which point it goes thru the boost pressure failure again. If I drive the truck with the camper pulling up a steep hill and keep the boost pressure below 20-21, it runs perfect. Is the computer limiting the boost to 22psi to protect the engine? What is the max boost from a stock turbo with no HP increase? What is the max safe boost for this engine? Could my delete tune be what is killing the boost? What mechanical issue could cause this problem?
Thanks for any info, Hitman
 
Max boost stock is upper 20’s on a SO. It could be the tune or turbo actuator. Have you talked to the tuner?
 
I have not contacted the tuner, I would like to hear if other Ram owners who has possibly seen this issue on their trucks.
 
Tune could be de-fueling due to EGT when hooked up.

Most of these delete tunes are hot garbage. Emphasis on hot.
 
I have seen 32 psi on my stock 22’ SO 2500.
Have you tried dropping a gear to raise rpms and reduce egt’s ?
 
OLEJOE said:
I have seen 32 psi on my stock 22’ SO 2500.
Have you tried dropping a gear to raise rpms and reduce egt’s ?
Click to expand...
I have not tried that but read about doing that when I started looking for the reason for my problem. Makes sense. Thanks
 
@Hitman - I think @AH64ID is likely on the right track when he suspected the turbo actuator.
Seems to be a very common issue on these trucks for some reason.
I think you would have gotten an under boost CEL, so not sure.
 
johnnyroastbeef said:
@Hitman - I think @AH64ID is likely on the right track when he suspected the turbo actuator.
Seems to be a very common issue on these trucks for some reason.
I think you would have gotten an under boost CEL, so not sure.
Click to expand...
The truck has not showed an error code. It has failed on me 5-6 times with no codes. I finally watched the turbo boost screen while pulling my camper, that's when I saw that when it got to about 22 psi boost that the engine will shudder and then I can't get above 9 psi until I stop the engine and restart it. After restart the boost works like normal until it gets to 22psi again. I finally drove it and kept the boost below 22 psi and it ran with no failures. It never fails when driving the truck without the 13,000 lb camper, of course the engine doesn't need 22 psi of boost just to pull a small trailer or no load at all. Thanks
 
Hitman said:
I have a 2022 Ram 2500 6.7 Cummins, It has been deleted with no HP increase above stock. The engine runs great when unloaded, if I accelerate quickly the turbo boost will go to the 12-14 range with no issues. The engine performs perfectly when using the exhaust brake. When towing my 13,000 pound camper it runs great and pulls like a train until I go up a steep hill. The engine will stop pulling for maybe a second and then resume pulling with reduced power. I finally monitored the boost pressure while pulling the camper, the engine pulls great, but when the boost gets to about 22psi or so is when the engine stops pulling for a second or so and then resumes pulling at reduced power and the max boost I see is 8-9psi. When I stop and turn the engine off and restart it to resume my trip the engine runs great again with the boost able to go back to 22psi at which point it goes thru the boost pressure failure again. If I drive the truck with the camper pulling up a steep hill and keep the boost pressure below 20-21, it runs perfect. Is the computer limiting the boost to 22psi to protect the engine? What is the max boost from a stock turbo with no HP increase? What is the max safe boost for this engine? Could my delete tune be what is killing the boost? What mechanical issue could cause this problem?
Thanks for any info, Hitman
Click to expand...
I had the exact same symptoms after a stock emissions off tune on my 2022. You need to change your map sensor and possibly plug your throttle valve back in afterwards depending how it reacts with the new map sensor. Open a support ticket with your tuner and they will tell you the same thing I suspect. They will also send you the sensor but I'll attach a photo of the one required.
 

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saltfarmer said:
I had the exact same symptoms after a stock emissions off tune on my 2022. You need to change your map sensor and possibly plug your throttle valve back in afterwards depending how it reacts with the new map sensor. Open a support ticket with your tuner and they will tell you the same thing I suspect. They will also send you the sensor but I'll attach a photo of the one required.
Click to expand...
Thanks for your response, I'll check on the sensor. I have another question, does the truck have a sensor to monitor exhaust gas temp? Could the engine cut the boost to protect itself from high EGT? Would a 5" exhaust lower EGT better than my 4" exhaust?
 
Hitman said:
Thanks for your response, I'll check on the sensor. I have another question, does the truck have a sensor to monitor exhaust gas temp? Could the engine cut the boost to protect itself from high EGT? Would a 5" exhaust lower EGT better than my 4" exhaust?
Click to expand...
I’m far from an expert with minute details of modern diesel tuning, but any good tune that’s close to a “stock” power level should have no issue with you holding it to the boards with a stock exhaust.
 
Hitman said:
Thanks for your response, I'll check on the sensor. I have another question, does the truck have a sensor to monitor exhaust gas temp? Could the engine cut the boost to protect itself from high EGT? Would a 5" exhaust lower EGT better than my 4" exhaust?
Click to expand...
I'm not an expert with EGTs but from my personal experience I've never seen high temps with a stock tune and exhaust. I believe your issue is the MAP sensor located on the intake horn.
 
@Hitman did you figure out what was going on with your truck? What was the final fix?
I'm experiencing the same thing
 
I have not corrected the problem as of yet. I hate to start buying parts without knowing if they will fix the problem. Salt farmer had the same issue, he replaced the MAP sensor. Is there a test procedure for the MAP sensor?
 
Hitman said:
I have not corrected the problem as of yet. I hate to start buying parts without knowing if they will fix the problem. Salt farmer had the same issue, he replaced the MAP sensor. Is there a test procedure for the MAP sensor?
Click to expand...
The part # he gave you is for an 18 model. I read tis somewhere else also about getting a map sensor for a 13-18. I just did mine the same as you and also pull a 12,000 lb fifth wheel. Have not towed with it yet though.
 
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