What would cause a car to make vacuum at WOT?
Thread Starter
0.0 BAR
Joined: Jun 2005
Posts: 0
From: WA
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.
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.
1.5 BAR
Joined: Dec 2006
Posts: 1,049
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
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
Thread Starter
0.0 BAR
Joined: Jun 2005
Posts: 0
From: WA
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.
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.
0.0 BAR
Joined: Feb 2003
Posts: 0
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?
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?
0.5 BAR
Joined: Oct 2008
Posts: 136
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
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
3.0 BAR
Joined: Oct 2006
Posts: 2,329
Re: What would cause a car to make vacuum at WOT?
Originally Posted by Emperor
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
jbweld is maybe too ghetto for that ;-)
weld the holes and call it a day
cause it sounds for me like a leak somewhere
