still no power under 4k :(

[laxmax327]

well ive been trying to fix the lack of power under 4k. i know you would think secondaries... duh. but no. i even unplug em to make sure. the car didnt even drive any different w/ them unpluged. the power just came on a bit smoother around 4k. but normally its a snail, until it hits 4k, then you can hear em open up and the tires break loose and the thing takes off like a rocket. plenty of power up there. every second from 4k to 7k it just keeps pulling harder. its very odd. i can floor it coming off a red light. tires wouldnt even squeell and you dont even get pushed back. i thought possibly the maf, so i cleaned that. made no difference. i know that shos shine in the high rpms, but i think this is just rediculous. what could cause it to run like the secondaries are open always even though their not. i know for a fact that they do function. so im lost here. the thing feels like it has a full out race cam or something. best way i can describe it.

edit: only other thing i can think of. i may have a vacum leak. sometimes i can slightly hear an odd air sound. but im pretty sure its just the intake. its really hard to hear over the exhaust and intake. and i cant hear the leaking when its just idling and im checking under the hood. it only when im driving and and engine is under some stress. but like i said, theres a good chance its just my intake. ive looked at every vacum line i could see and tried to find something leaking. any specific ones to double check that could be causing this?

 

[LeddZepp8687]

It may sound stupid, but your TPS is prolly bad. Same thing w/the MTX happened, Had absolutely no power under 4k. Then I put a 69mm throttle body on that was purchased used and included a new(ish) TPS, now the car has a good ammount of low end as well as superior top end.

I'd replace the TPS

 

[laxmax327]

sorry, its a 92 mtx. forget to say that. but thanks. even if it were bad it might not throw a code? ill try to pick another one up cheap to see if it helps.

 

[Mac]

Also, when was the last time you put in new plugs/wires? I had a similar problem that was solved with some maintenance.

 

[F-22 Raptor SHO]

Just to make sure we are all on the same page, you said its not the secondaries because you unplugged them and had no change. When you are under the hood revving the motor, do you see the secondaries open and close past 4k?

 

[laxmax327]

sorry raptor, but yes, im positive they were functioning. i watched them open and close at 4k, then i unpluged it, then they opened and stayed that way. then i went for a drive, but it didnt even feel any different as it normally did. it just got into its power smoother.

 

[SHOsFAST]

I think I'm lacking low end power too(first SHO I've owned so I don't really know), just doesn't seem as powerful as it should, but at 4 grand she opens right up. Any updates or fixes??

 

[seraphiem]

How's the condition of your plugs and wires?

How clean is the intake and you really REALLY sure the secondaries are properly closing?

My MTX was dead until 4k and you felt all that mysterious torque appear and hit you across the face. New plugs and wires really helped with that.

 

[laxmax327]

no clue about plugs and wires. will be replacing them soon though as it seems like it might be the cause. as far as i can see through the tb the intake looks really clean though. i can physically see each secondary thing move at 4k. im positive they're working. i think i might actually have a very slight miss down low too. didnt notice it before. but now thinking about the plugs it sometimes feels like it. so new plugs and wires it is. ill let you konw if it fixes it.