6.4 boost/mileage question

08Monster · Dec 11, 2014

I meant 44. Idling BP is 16.0

08Monster · Dec 11, 2014

Rechecked it, the last test was done with the truck locked in 2nd, must have been what caused the high number. In OD, boost and EBP are very close. Has never happened in the summer.

footlong70 · Dec 11, 2014

08Monster said:
Rechecked it, the last test was done with the truck locked in 2nd, must have been what caused the high number. In OD, boost and EBP are very close. Has never happened in the summer.

Then its a frozen tube. It might not always be frozen either so it might have been thawed when you tested it. I know its above freezing temps up here in Canada so I would think its fairly warm there too. But I guarantee it's your issue. You either have to ditch the tube or relocate the sensor to a warmer spot.
Personally I just removed the tube and put the sensor directly into the same spot on the egr catalyst pipe with a JIC collar IIRC. It has never froze since, even at -35c on the highway.

08Monster · Dec 19, 2014

Towing again, 210 tune, flat ground is 26psi of boost. EBP is 41.4. Frp is 12.7k

ckrueg · Dec 20, 2014

That seems really high, With the h&s my boost is usually 7psi ebp is about 11

footlong70 · Dec 20, 2014

08Monster said:
Towing again, 210 tune, flat ground is 26psi of boost. EBP is 41.4. Frp is 12.7k

Did the bp move much or stay fairly close to 41psi regardless of boost pressure during that trip. Either way boost is too high and it's a bp sensing issue.

08Monster · Dec 20, 2014

It moved with the boost footlong70

footlong70 · Dec 22, 2014

Still out of whack though. 26psi is too high flat ground, and your ebp should be within a couple psi unless your accelerating. Gotta change something....change the sensor, ditch the tube, or relocate the tube... Did you ever cycle the actuator arm by hand with the truck off?

nick01 · Dec 22, 2014

I just towed about 4k on hd300 mostly flat but some hills and never saw that kind of boost. Even when I accelerated pretty hard due to a dumb driver merging into me I only saw about 40 psi 3/4 throttle. I also was able to get 14.1 MPG and my computer is usually only .5 off unloaded.

Something is up with your truck. I am no expert so I have no clue what it may be. Just trying to give you something to compare with. Also I'm on 37 Trail Grapplers 6in Lift.

ckrueg · Dec 22, 2014

I agree, even towing it takes a big hill or hard acceleration to break 40 psi ebp

08Monster · Dec 22, 2014

Actuator arm moves fine. I'll try to clean the tube and change the sensor soon. It's not a frozen tube, I pulled yesterday above freezing and it still ran 25psi on the flat, 35+ on hills. Spartan 210. A dashdaq doesn't take out air pressure. So when it reads 40, its actually about 15-16psi less. That makes it a 1:1 actual ratio. Thats why I'm confused.

footlong70 · Dec 22, 2014

bad sensor then I would say. But yes clean the tube, remove the block off plate too in order to make sure its not full of water in the catalyst pipe. Changing the sensor wouldn't hurt either, other than your wallet.

08Monster · Dec 26, 2014

It's not a bad sensor. What next? VGTDC is 58 while cruising at 70. Fluctuates maybe 1%

footlong70 · Dec 27, 2014

Did you clean the tube? Or remove the block off plate? They've been known to fill up with water down there from condensation and exhaust over time.

08Monster · Dec 27, 2014

New tube, never checked the block off plate. The one that is right beside the sensor?

footlong70 · Dec 27, 2014

Your still having over boosting issues? With the truck off, whats ebp showing? Start the truck, then whats ebp? Go for a drive and get on it a couple times, stop and check ebp at idle again. Turn the truck off, check ebp reading.
Yes, right beside where the tube connects to the catalyst pipe. The block off plate where the egr cooler use to connect. Some have reported significant amounts of water trapped at the bottom of the pipe. Enough to to fill the bottom of the pipe. If that's clean and good to go then the last thing I believe it could be is something directly wrong with the VGT. The only way you can make 60 psi boost with stock turbos and fuel is the vgt is not opening. The vgt is only going to stay closed if the ebp sensor is telling it to or the vgt is malfunctioning/broken.

08Monster · Dec 29, 2014

14.2 with truck off, 17.4 idling, 20 idling at 5x WOT pulls, 17.5 with truck off after WOT pulls

08Monster · Dec 29, 2014

Is there anyway I can test the VGT? The fins are definitely not in the right position. @70mph, it's at 60% duty cycle. Floor it and it drops to 6.001.

08Monster · Dec 29, 2014

Also, its got no power up top. I just was empty, no trailer, and floored it going up a hill,it's pretty steep, normally it pulls like a freight train on crack up it, but boost shot up and I never gained any speed. 210 tune, I hit 51psi of boost and backed off the throttle with not much acceleration at all