[MonsterJL]

Anyone have any clue why I'm suddenly making no boost, I was getting 2 errors on the dash both which were P2122 and P2127 which have something to do with accelerator pedal sensor, switched it out and still getting no boost while full throttle, odd thing was that it randomly started giving boost for 1 full day. Parked the car overnight and suddenly back to no boost on throttle. Very confusing no clue where to start from on trouble shooting.

Thank you for any help

 

[MonsterJL]

I should specify I am not stock, have a couple bolt ons and tune including:
E85 Tune, 180 termo, Catback Exhaust, Headers, 2.85" pulley, ATI Harmonic Damper 10% over drink w/ pinned crank shat, 1300cc injectors and upgraded spark plugs

 

[Philth]

Have you tried a relearn of the throttle position? What tuning device do you use? If it's HP, you should be able to log TPS voltage and input to verify.

 

[Double G]

Wondering if your boost bypass is not closing as this would prevent boost from building. It is a small electric throttle body from a 4cyl Mopar vehicle that the drive motor could fail and the supercharger would be in bypass mode all the time hence not making any boost.

It works just like your main throttle body but I do not know what parameter you would data log to record the bypass valve closing percentage to see if it is working or not.

 

[Philth]

Wondering if your boost bypass is not closing as this would prevent boost from building. It is a small electric throttle body from a 4cyl Mopar vehicle that the drive motor could fail and the supercharger would be in bypass mode all the time hence not making any boost.

It works just like your main throttle body but I do not know what parameter you would data log to record the bypass valve closing percentage to see if it is working or not.

I'm at work right now so I cant access my HP Tuners but I was just researching this. I'll get back later on tonight with the answer, but there's a voltage table to reference. It's something like 4.5 volts open then you are looking for a drop during WOT. More to come later on with the name and values.

 

[MonsterJL]

thank you guys, really appreciate it. we are still trouble shooting here

 

[MonsterJL]

So there is some suspension of it being the clutch of the upper pulley not engaging or something along those lines. What are your guys thoughts

 

[30birdy99]

I would definitely recommend removing and inspecting the blower internals, upper pulley clutch and blower rotors. I also read your crank was pinned, so no chance the lower pulley is spinning on the crank? Bypass valve stuck open?

 

[Lil Hemi]

Pull the blower belt off and spin it by hand. I would think you’d be able to feel it if there was a clutch issue. I’m running a grip tech upper so there is no “clutch”

 

[Double G]

Agree, pull the supercharger belt and spin the pulley by hand, you can tell by spinning the pulley if it is turning the rotors or not.

Under throttle do you still hear the whine of the supercharger when driving?

 

[MonsterJL]

Agree, pull the supercharger belt and spin the pulley by hand, you can tell by spinning the pulley if it is turning the rotors or not.

Under throttle do you still hear the whine of the supercharger when driving?

nope no whine of SC while throtlle its completely disengaged

 

[Philth]

Sorry, I've been super busy. Haven't been able to get to my HP tuners (just got to work and saw this thread as a reminder) Were you able to log anything for the bypass valve?

If you haven't already, pull the belt like mentioned and see if you can feel resistance while spinning the pulley. If you rock the pulley back and forth clockwise to counterclockwise, you should feel the lash from the SC gears. Worst case...pull the lid off and you can see the rotors move then.