[99v6stang]

Okey so many of you have probally read one of my other threads and kinda know my car situation, but anyways here is the problem. My car (131,000MILES)(automatic) is very very slow but after all i have done to it, it sure shouldnt be this slow. I have so far done the following stuff...

F150 4.2 just rebuilt, moly rings, new bearings, heads redone...
Hand ported and polished 4.2 heads
Gasket match ported and polished lower and upper intake
Morana racing 224/224 110lsa reground cam
Longer Push rods
Heavier comp cams springs and retainers
Bomz fenderwall cold air intake
Sniper 4.2 tune from dirtydirty racing
Mac longube headers
Mac h pipe with dual high flow cats
Mac catback
Trac-loc
4.10's

And ASP 25% underdrive pullies are on their way
and the fuel filter and plugs were replaced very recently, also 5 of the wires are brand new but one is unknown

Anyways my car is currently tuned to run at 800 rpms, but when it is first turned on it jumps to almost 2000 rpms, shakes, and kills. If i give it gas for a while it will then idle but fluctuate from 600 to 1200 rpms, but mainly hangs around 800. Then after the car is running for awhile and all warmed up, i give it gas from a dead stop and the tires dont even so much as squeak, they do however squeal shifting into second as it is tuned for a firm shift. Also i just came back from racing a bone stock GTP (1999 style) and he destroyed me. They have 240 horsepower, and i figured my car should be about that rwhp. Now the gtp does have 280 lb-ft torque and i expect mine to be less but not incredibly less.
So im thinking my fuel pump or possibly injectors are going bad, but then i dont understand why it would run fine at high rpms.
My Second thought is that i need a wideband because it is simply too much to tune without afr
My final and what i think is most likely is a bad pcv valve or a vaccum leak

The problem is that i cant afford to fix all of these problems, so i really to decide what the problem actually is, so any help would be GREATLY appreciated.

[El_Cangri]

since ur having a bad idle i would think u have a vacuum link..

also a wideband would be a good idea to get a better tune u know

[Hourofpain]

either a vac leak.
or somethings fucked up in your fuel system

[2002BLGT]

Are you getting a check engine light ? if so what is the code ? advance auto or autozone will check it for free.......
Next buy a 18 dollar vacuum gauge from a parts store and see how much vacuum you have at idle , you should have atleast 15-17 of vacuum , here is a link to a cheap one
Actron®
Next would be to do a compression and leak down test ?
here is a cheap compression tester
Actron®
Also how was the cam installed ? Was it degreed ? these are the first things you need to check and it does not cost that much , if you dont find something by now only then I would be to buy a wideband , AEMs are probably the best for the money that have their own monitor you can mount in the car .....

[99v6stang]

yea, there is a check engne light on, i will get that checked out tommorow as well as check for a vaccum leak. And im not sure as to how the cam was put in as it was done by my mechanic. Could you describe the degree process?

[99v6stang]

ok i got the codes read, and purchased a vaccum tester that i will use after making this post. I showed two codes... 1151 and 1131
1151
Lack of 02 switches- banks 2 sensor... ecm couldt not adjust fuel trim because of a rich or lean condition
1.Fuel pressure high or low
2.MAF sensor ditry or defective
3.vaccum leak
4.leaking injector or pressure regulator

1131
Lack of bank 1 02 transitions- lean... ECM detected bank 1 02 at its lean limit
1.misfire on bank 1
2.vaccum leak affecting only bank 1
3.Fuel injector problem bank 1
4.Engine mechanical condition

So..... help??????

[SSStang]

Originally Posted by 99v6stang ok i got the codes read, and purchased a vaccum tester that i will use after making this post. I showed two codes... 1151 and 1131 1151 Lack of 02 switches- banks 2 sensor... ecm couldt not adjust fuel trim because of a rich or lean condition 1.Fuel pressure high or low 2.MAF sensor ditry or defective 3.vaccum leak 4.leaking injector or pressure regulator 1131 Lack of bank 1 02 transitions- lean... ECM detected bank 1 02 at its lean limit 1.misfire on bank 1 2.vaccum leak affecting only bank 1 3.Fuel injector problem bank 1 4.Engine mechanical condition So..... help??????

Holy lord, I would stay out of that car...
I've never even seen a code say the 02 sensor was at its LEAN LIMIT

[99v6stang]

well that isnt good because i have been driving it alot and pretty hard too.

[Hourofpain]

start checking your sensors

check your vaccum lines.

check your injectors to make sure there not foul.

make sure your egr is installed right.

[Hourofpain]

fuck that

get that lawyer on the phone

[99v6stang]

i just check the vaccum lines, and when looking at the car from the front.... i plugged the tester into the far back left connection on the upper intake mainfold and it read 12.5. i also check at the front right two connections of the upper intake manifold and they were at 12.5 as well But i am noticing some kind of tapping and it seems slightly louder than it was a week ago. I know i have an exhaust leak but i dont think that is what it is.

The o2 senors are very new but i will recheck their connections.

What do i look for on the injectors? The car was just rebuilt and i would think the mechanic would have checked this.

i will check the egr

[SSStang]

Who built the engine again?

224/224 seems like a big cam for n/a , did you have it dyno tuned?

[2002BLGT]

Originally Posted by 99v6stang i just check the vaccum lines, and when looking at the car from the front.... i plugged the tester into the far back left connection on the upper intake mainfold and it read 12.5. i also check at the front right two connections of the upper intake manifold and they were at 12.5 as well But i am noticing some kind of tapping and it seems slightly louder than it was a week ago. I know i have an exhaust leak but i dont think that is what it is. The o2 senors are very new but i will recheck their connections. What do i look for on the injectors? The car was just rebuilt and i would think the mechanic would have checked this. i will check the egr

12.5 would tell me you have an intake gasket leak , you should have 15 or very close inches of vacuum at idle even with that cam

[Hourofpain]

time to pull the head off

[2002BLGT]

this guy just PMed me, he had wires pulled out of the o2 sensors , so thats atleast part of the problem ........id still pull the intake and check for gasket leaking , 12.5 just seems like not enough vacuum to me , and if you are noticeing a tapping that could be an exhaust leak which will cause the o2s to read lean as well ...........

[99v6stang]

I located a possible problem with the vaccum lines. there is a line on the way back of the lower intake manifold but it isnt hooked up to any thing and i cant seem to figure out where it goes to. Also, i do have and exhaust leak from the exhaust manifold gasket, but there is another seperate tapping noise.

[99v6stang]

The engine was mainly built by me, with help from a firends dad who is a mechanic. And yea i know the cam is a little big, but im going to add a supercharger in a few months. And no it has not been dyno tuned

[2002BLGT]

Originally Posted by 99v6stang I located a possible problem with the vaccum lines. there is a line on the way back of the lower intake manifold but it isnt hooked up to any thing and i cant seem to figure out where it goes to. Also, i do have and exhaust leak from the exhaust manifold gasket, but there is another seperate tapping noise.

If you have something tapping the in valvetrain , pull the valve covers off and do a visual inspection first ....you might have a rocker arm that has backed off .....

[99v6stang]

ok i will check that tommorow when i start working on the car

[SSStang]

Originally Posted by 99v6stang The engine was mainly built by me, with help from a firends dad who is a mechanic. And yea i know the cam is a little big, but im going to add a supercharger in a few months. And no it has not been dyno tuned

Then why are you wasting money on UDP's if your getting a supercharger. You might want a dyno tune..