feels like my car is pulling back power

Spiced MSP

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2016 Peterbilt 579
(scratch)For some reason, when I am driving my car, as soon as my car sees boost it feels like it pulls back power. It drives fine during regular driving, but as soon as my boost gauge touches 0 or higher, it feels like the engine rocks and if I gradually give it more gas and get more boost, it will rock again and it feels like it is the car is losing power or something. The rocking thing with the engine is not huge, but I can feel a slight rocking motion as soon as the car sees boost. Of course the engine moves during gas on/gas off driving or shifting but this is not that. I gradually give it gas until the needle on the gauge reaches 0 and it pulls back. Any higher in boost and it feels like it pulls back more. any clue what it is? I don't want to blow my motor. I am ordering a split second air/fuel and timing controller and rear motor mount this week.
 
Running higher than stock boost can easily cause fuelcut but that usually more violent like hitting a wall. I would check your plugs first to see if they look healthy if they are looking a redish brown you are running lean and shiny specs on them would be from detonation. Could be bad coils they are a common failure or the wga could be bad causing you to run higher boost and run out of fuel.
 
Running higher than stock boost can easily cause fuelcut but that usually more violent like hitting a wall. I would check your plugs first to see if they look healthy if they are looking a redish brown you are running lean and shiny specs on them would be from detonation. Could be bad coils they are a common failure or the wga could be bad causing you to run higher boost and run out of fuel.

thanks for the info, I replaced my coils recently and I have experienced fuel cut before so I know it is not fuel cut. I will check my plugs and see how they look. It could be my wga but I tested the actuator recently and it was good. But, how could it be from running higher boost if it happens as soon as the needle on my boost gauge reaches zero. My car barely sees boost because I don't want to risk a blown motor.
 
Have you checked your intercooler piping to make sure you don't have a leak somewhere? Mine did that once when I forgot to tighten a coupler on the hot side.. I wondered why I wasn't able to boost at all yet I was still able to drive it.
 
Have you checked your intercooler piping to make sure you don't have a leak somewhere? Mine did that once when I forgot to tighten a coupler on the hot side.. I wondered why I wasn't able to boost at all yet I was still able to drive it.

no, I will check that and see how it drives
 
Same

no, I will check that and see how it drives

Before I upgraded to the SLS Hot Pipe....the stock plastic pipe had a nice tear/hole in it...still allowing me to drive, but basically 'bucking' the second it got to 0. Sure you can get it PAST 0, but most of the air is escaping I'm sure.

Anyway, it bucked around enough to break the intake vibra-mount thing, and obviously I couldn't boost...so...it was time to fix!! But yeh, didn't see hard pipes or anything on your mod list, but maybe I skipped over it...if you have the stock one still, it might be broken now....but even when I put on the SLS pipe, the couplers weren't tight enough initially so I still had leakage.
 
Before I upgraded to the SLS Hot Pipe....the stock plastic pipe had a nice tear/hole in it...still allowing me to drive, but basically 'bucking' the second it got to 0. Sure you can get it PAST 0, but most of the air is escaping I'm sure.

Anyway, it bucked around enough to break the intake vibra-mount thing, and obviously I couldn't boost...so...it was time to fix!! But yeh, didn't see hard pipes or anything on your mod list, but maybe I skipped over it...if you have the stock one still, it might be broken now....but even when I put on the SLS pipe, the couplers weren't tight enough initially so I still had leakage.

I have a FMIC, no plastic pipes anywhere. I will check all of my couplers and make sure they are tight. I just recently noticed it could be my BOV also. The piston may not be seating all the way.
 
sorry guys, I know it is hard to help. But, it is hard to actually explain what my car is doing. For instance, If I am driving at highway speeds(65+ mph), and I very slowly start giving the car more gas, the needle on my boost gauge starts to rise. As soon as the needle reaches zero, it feels like the engine rocks and the car loses a little bit of power. Someone on another forum mentioned that it could be my rear motor mount. I don't know. I am ordering the rear mount next week anyway. I already know how much of a b**** it is to replace it. But, I have access to some air powered tools and a lift at a garage here on Ft. Hood. Thanks for the info so far guys. I really appreciate it.
 
cool. i have both f and b awr i think i got 90. the car feel cool when they where installed. well good luck
 
yeah, I am going to order the rear mount next week, I am not looking forward to installing it though. lol

my rear mount is bad now but i really only feel it if I get snappy with my shifts. A bad mount isnt going to give you a decrease in power feeling though. Replacing the front and back though will give you a much tighter nicer feel. I replaced all mounts except for the rear.
 
my rear motor mount is going on soon the engine rocks allot if i roll over train tracks or shift fast
 
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