WOT problem
fix the vacum leak and start from there... could also be an exhaust leak... if it were fuel it would get better when the car got warm...sounds like o2 sensors, exhaust leak, vacum leak, or bad maf/ maf plug. The map sensors rarely go bad but its a possibility. car has to be running very lean to throw code for it. If it is falling on its face and it were do to it running lean it would throw the code for sure. Sounds like vacum leak to me but i havnt been there to see and hear the problem in person so its a guessing game.
lets us know
Well it still does it when im all the way to the floor on the gas, so if it goes into open loop when that happens, only thing that makes sense is the maf or something. Because it runs great when cold so the pump wouldnt be a factor anymore.
What spark plugs are you guys running. What would be the recommended gap for a 2004 LQ4?
What spark plugs are you guys running. What would be the recommended gap for a 2004 LQ4?
Well it still does it when im all the way to the floor on the gas, so if it goes into open loop when that happens, only thing that makes sense is the maf or something. Because it runs great when cold so the pump wouldnt be a factor anymore.
What spark plugs are you guys running. What would be the recommended gap for a 2004 LQ4?
What spark plugs are you guys running. What would be the recommended gap for a 2004 LQ4?
Please check ur fuel psi while the car is acting up(under a load).
After that u can rule it out. If u dont have a scanner(for data not codes) use a voltmeter and tie into ur O2's and see if the car is going lean when is falls on its face.
keep us informed
Well i replaced the TPS sensor and she idles great now. No more Idle surges or anything.
Still having that huge power loss when i punch it. It runs great when i first start it up if it hasnt been running for awhile. So im guessing when it goes from Open loop to closed is when it falls on its face.
Still having that huge power loss when i punch it. It runs great when i first start it up if it hasnt been running for awhile. So im guessing when it goes from Open loop to closed is when it falls on its face.
I had a small fly disable a lexus before(no power under full throttle) the fly some how got pass the airfilter and stuck on the MAF wire. it would idle and drive ok till u stomped it. Maybe want to check that after u check fuel psi.
Had a 2004 chevy truck the other day with weak fire on all the coils..it bogged under a load. it was the bad ground on the driverside of the engine block. may want to look at that also.
let us know
like i said before, easy check. unplug the maf and either drive the car and put it in the rev range where your having problems or do it at a stop if your having the problem there as well. if it clears up you most likely need a maf. sometimes it won't throw a circuit code but they can still be faulty.
Teching In
Joined: Sep 2006
Posts: 13
Likes: 0
From: Chicago
Well i replaced the TPS sensor and she idles great now. No more Idle surges or anything.
Still having that huge power loss when i punch it. It runs great when i first start it up if it hasnt been running for awhile. So im guessing when it goes from Open loop to closed is when it falls on its face.
Still having that huge power loss when i punch it. It runs great when i first start it up if it hasnt been running for awhile. So im guessing when it goes from Open loop to closed is when it falls on its face.
I got a vacuum leak so I'm gonna put a TPS on it?????? My engine is blown so I'm gonna put a new rear end in the car???? You can lead a horse to water but you cant make it drink............ I'm not trying to be a dick but you said there was a vacuum leak at the back of the intake but did nothing about it why would you ignore that??? You have more air in the engine then the mass air sees.. The mas air measures the air to see how much pulse with to give the injectors(among other inputs) So air that is not read by the mass air is not in the pcm's equation. Im not saying it will fix your problem but your chasing GHOSTS until you fix it...
Last edited by Hasstle95Z; Nov 20, 2009 at 09:33 PM.
Whats the best way to check for a vacuum leak? Or where to find out where its coming from.
I have a suspicion its coming from the rear of the truck intake (LQ4 Motor). Theres that part on the back of the truck intake im using for my brake booster, but idk where to buy a plastic piece that fits into that to hook a hose up to it, so i found a small metal pipe that i fit into it and clamped a hose on it.
Anyone know where i could pick up a fitting for that hole on the back of the truck intake?
thanks
I have a suspicion its coming from the rear of the truck intake (LQ4 Motor). Theres that part on the back of the truck intake im using for my brake booster, but idk where to buy a plastic piece that fits into that to hook a hose up to it, so i found a small metal pipe that i fit into it and clamped a hose on it.
Anyone know where i could pick up a fitting for that hole on the back of the truck intake?
thanks
I wouldnt think it was the maf since it only started bogging when it was on for 5 or 10 minutes. Could anyone explain that to me? thanks!
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
On The Tree
Joined: Aug 2007
Posts: 175
Likes: 0
Had the same problem. Posted this same issue on several forums and no body had a clue. I could do a nice burn out when cold but when it got into operating range it would just about fall on its face. I brought it to the dyno to see if he could figure out the issue but the problem really didnt show up like it did on the street. After going in and out of HPTuners and looking over everything about a 100 times, turns out that the TCS was enabled and retarding the timing big time. Look in the Engine, tourque management, there are a few tables that need to be modified. I now can do full burnouts and have the trans shifting like it was pro built without having pressures boosted to max and still have tranmission tourque managment enabled.
