WOT problem
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
Teching In
Joined: Sep 2006
Posts: 13
Likes: 0
From: Chicago
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
You can just spray carb cleaner or brake cleaner on it and see if the idle changes. It sounds like a vacuum related problem for sure. You are either bypassing the MAF with unmetered air or the MAP sensor is taking a crap on you.
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Verdad Gallardo well this morning it was about 40 degrees, cold start and gave it some gas on my way to work and sure enough it did the same thing, falls on its face. So ill try spraying carb cleaner to find the issue
So a vacuum leak would cause my truck to idle up and stay at 2000 or 1500 rpm by itself when just touching the gas barely?
So a vacuum leak would cause my truck to idle up and stay at 2000 or 1500 rpm by itself when just touching the gas barely?
When the engine gets warm, at about maybe 70% throttle it feels like it holds back. Hard to explain.
But if the engine is cold there is no problem.
But if the engine is cold there is no problem.
well this morning it was about 40 degrees, cold start and gave it some gas on my way to work and sure enough it did the same thing, falls on its face.
Man your kinda of all over the place with you description dont you think?. Find and fix your vacuum leak.
Teching In
Joined: Sep 2006
Posts: 13
Likes: 0
From: Chicago
no power Did u check fuel psi at idle or under a load(full power)? Need to check it while driving it. Have u checked ur fuel filter?
Truck intakes are bad about the intake gaskets leaking causing a vaccum leak. Normally this shows up when they are cold and after the engine warms up it seals the leak but urs is doing the opposite.
If u want to check ur cats then u need a back pressure gauge or remove the O2's and see if it runs better.
Have u cleaned ur mass air?
The o2 could be bad but at wot the pcm goes into open loop and rules that out.
let us know
Truck intakes are bad about the intake gaskets leaking causing a vaccum leak. Normally this shows up when they are cold and after the engine warms up it seals the leak but urs is doing the opposite.
If u want to check ur cats then u need a back pressure gauge or remove the O2's and see if it runs better.
Have u cleaned ur mass air?
The o2 could be bad but at wot the pcm goes into open loop and rules that out.
let us know
TECH Regular
Joined: Sep 2006
Posts: 447
Likes: 0
From: Houston
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.
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.
On The Tree
Joined: Nov 2007
Posts: 101
Likes: 0
From: Collierville, TN
I have a similar problem with my car.
Its got LT's, lid, and true duals, and every once in a while when I go WOT, it wont pull. The rpm's climb slowly, then kinda stop around 5000rpm(+/-). the car wont have power period...
However, it isnt dependent on engine temperature. I dont ever get on it when its bone cold, but when it isn't fully warm and I go 50-70% itll go kind of the same thing.
My car isn't tuned yet, so Im hoping its a tuning issue, but can anyone tell me if thats what it is for sure? I thought it was the damn transmission slipping, but I hooked up a TechII and it didnt show any trans slip codes....
Its got LT's, lid, and true duals, and every once in a while when I go WOT, it wont pull. The rpm's climb slowly, then kinda stop around 5000rpm(+/-). the car wont have power period...
However, it isnt dependent on engine temperature. I dont ever get on it when its bone cold, but when it isn't fully warm and I go 50-70% itll go kind of the same thing.
My car isn't tuned yet, so Im hoping its a tuning issue, but can anyone tell me if thats what it is for sure? I thought it was the damn transmission slipping, but I hooked up a TechII and it didnt show any trans slip codes....