New throttle, losing power

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YBLEGAL

Regular Member w/ Cheese
Hello all. I just put a new throttle body and map sensor on my B16 SiR-II. The throttle is 70mm, and my old one is 60mm. Now when i'm pressing the gas to full throttle, i lose power, like the engine can't do that. Could this be because my intake manifold is still small (60mm i'm guessing) and the map sensor is reading wrong then. Or could the map sensor be faulty. I had to order a new map sensor, so this one i'm using is from ebay. JDM to USDM throttle conversion... Aside from that, i installed 4-1 headers in the same job, but i'm really doubting that's the problem, but worth mentioning. Thanks for the advice!!
 
unless you have an aftermarket intake mani or have yours port matched with the head and TB .. its not gonna do much..
 
i do have an intake, which is that size, it's just that the intake manifold is small still, so that's y i cant press the gas that hard eh? that's all i'm wondering,
 
I know it's not going to do much, that's not what i'm worried about. It's the fact that now under full throttle the engine doesnt go, "full throttle" is about 1/4 distance from the floor. So what i'm trying to figure out is, if the MAP sensor is bad quick enough that i can send it back for a new one. The map sensor was Ebay'd. Used. I know the preformance isnt gonna go up much. But is that little intake mani the cause of my problem?

and then either way, that intake mani is gonna go soon enough. But what would you recommend:

1. Keep stock mani and have it bored out?
2. Buy an ITR mani and have it bored out?

which has better performance? I heard the ITR does cuz of shorter runners....but i'm not the richest, so i wanna make sure.
 
well.. put it this way... Skunk2 bases their design off of the ITR manifold.. you wouldnt need to have it port matched.. but it would help.. and to really notice those 2 modifications, you're gonna have upgrade your valve train and let you motor breathe easier
 
i've fixed the problem with WOT. had to adjust the tps sensor. but there's still a problem. .50v made the car run very very very raw as in you cant maintain a steady speed. you have to accelerate. if you try, it drops off, and then kicks in again, drops off, etc. very very irritating. also when set to this low a voltage, i get an intermediate rev point at 1500rpm. if i hit the gas harder it will pass that, but it's hard to drive slow. so if i set it above .80v it makes the ride much smoother. i dont have the 1500rpm problem either, i just cant floor it.

and i also think i'm throwin codes but, i dont know how to c it. you c, my mechanic that did the engine swap didnt hook up the check engine light... so i guess, can i wire an led off the wiring harness at some point? any ideas there? i'm pretty sure i'm throwin a code cuz occasionally it wont rev past 3500rpm. and i have to pull over and reset the ecu, then it works.

so any ideas?

thanks!! :D
 
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