What would cause a car to make vacuum at WOT?
 

I was tuning a car last night, and all was fine until we went above 5k. As soon as it got above 5k, the tracker would start going into vacuum columns. The car felt as if it not been at wot and were just holding the throttle down about half way and not accelerating anymore.

Its a stock f22a, h23 IM and TB, header and intake. Nothing special or impressive about it. Using a p28 with crome pro.

The afr's DID go lean, I tried richening the ---- out of the map with no luck.

We thought maybe it had something to do with the AEM rail and fpr, so we switched back to stock and same scenario, although it did idle a bit smoother.

I'm out of ideas for now. :S

Re: What would cause a car to make vacuum at WOT?
 

check the throttle cable.. make sure it's pulling the butterfly open properly at WOT.
check the TPS voltage at 0% and then 100% throttle.

does it idle good? if all are fine, just tell him to quit messing with cars ;D

Re: What would cause a car to make vacuum at WOT?
 

Clean the air filter O0

Re: What would cause a car to make vacuum at WOT?
 

Actually, I don't think he's running an air filter.

TPS reads 0% closed and only 94% WOT, according to crome. I'll test it via DMM when I get a chance. The throttle is opening all the way, we checked for that last night too.

Re: What would cause a car to make vacuum at WOT?
 

Are you at high altitude? How is your map sensor hooked to the engine?

Re: What would cause a car to make vacuum at WOT?
 

I'm in Orlando, so negative on the high altitude.

Map sensor is hooked up on the IM. nothing T'd off of it.

Re: What would cause a car to make vacuum at WOT?
 

High altitude won't make the engine draw vacuum at higher rpms.

The few times I've seen that it's on a built 2.1 liter with a stock 60mm TB that can't support 230+ whp worth of engine. AFRs were controllable, however, so you need to suspect either multiple problems or something ------- wierd.

My only constructive comment: IABs opening?

Re: What would cause a car to make vacuum at WOT?
 

IAB's deleted. He has a gutted IAB plate. JB welded the holes where the rod went through.

Re: What would cause a car to make vacuum at WOT?
 

i thinks thats the problem

jbweld is maybe too ghetto for that ;-)

weld the holes and call it a day

cause it sounds for me like a leak somewhere

i had a similar prob after a fenris bite the hose to my vacgauge ::)

Re: What would cause a car to make vacuum at WOT?
 

A boost leak downstream of the MAP would not cause the map to read vacuum. Just a boost drop.

Re: What would cause a car to make vacuum at WOT?
 

I dont think this car is boosted...

Hes runin IHE

Re: What would cause a car to make vacuum at WOT?
 

less than ideal ground effecting sensor readings.

Effecting the TPS and MAP

Re: What would cause a car to make vacuum at WOT?
 

Reading owns me.

Vacuum leak still wouldnt cause his problem.

Re: What would cause a car to make vacuum at WOT?
 

could quite possibly be it. He has a gay ass wire tuck(taped everything instead of soldering) and relocated battery to the trunk. I'll check existing and add some grounds this weekend.

Re: What would cause a car to make vacuum at WOT?
 

What?

---- that, tell him to fix his ignorant ----. There is no way to tune that crap with the wiring quality varying in direct proportion to humidity, temperature, and vibration. :l

Re: What would cause a car to make vacuum at WOT?
 

Re: What would cause a car to make vacuum at WOT?
 

But hey, it LOOKs good. Who cares if it runs liek horseshit running uphill? :1

Man I've trained MONKEYS to solder. Speaking of that monkey, you getting any better at that, Davis??

Re: What would cause a car to make vacuum at WOT?
 

My LS does it also. the larger TB helped. You think it was due to the cam's though.

Re: What would cause a car to make vacuum at WOT?
 

It's due to something in the intake tract; if anything the cams are doing a great job as the engine is breathing enough to pull a vacuum at WOT.

Re: What would cause a car to make vacuum at WOT?
 

Solved it, just a little unsure as to what exactly it was.

He had a 3" intake that went right behind his headlight, then it went to 2.5" to right behind his bumper lights.

I'm thinking there was some sort of restriction and the engine wasn't breathing enough up top. That, or 3" and that long piping is too much for a stock f22? I don't know, but problem solved and it's running like a healthy stock f22. lol

Re: What would cause a car to make vacuum at WOT?
 

Intake turbulence perhaps? weird.


I soldier airbag harnesses. Your life is in my hands >:D

Re: What would cause a car to make vacuum at WOT?
 

You know that bottom skid shield that goes under your fender? I guess his piping was touching it and I guess after 5k the engine was sucking enough to suck the plastic so the plastic was now blocking air.

That's the answer that makes the most sense right now. That part of the skid plate is pretty flimsy on accords, so yeah.