Chasing down an air leak........ could it be?

[PQ]

Originally Posted by HufferSS

If you trust him and he said your fuel trims were right then why are you chasing an air leak? Unmetered air will show in the fuel trims. Maybe your issues is mechanical...did you have a CAM installed? Maybe a tight valve or something?

I think I'd just take it to one of the guys who offered help...especially if you don't have the tools to diagnose....ie scan tool and/or smoke machine etc.

Well, since I left my scan tool with Vengeance, I can't log it.

But, since Mike said it was an air leak I guess he saw something in the trims that suggested to him that it was. I"m searching for air becasue that's what he said it was.

I stopped the spark search. So I don't know. But just now I just sprayed starting fluid all over the engine in any place that a leak would be. All around the manifold, air tube, throttle body, brake booster, all hoses... I pinched off hoses pulled them and plugged them. If it's a leak, it's on the inside. And I know better than that. It only started when I put the blower on and before I put any boost on it.

Originally Posted by Dr Jkel

Could it be a leak in the valves ?

Nope. That's not even possible because that would suck.

Originally Posted by John@APF

I'm not sure if its really a vacuum leak, we put a blower on a while back and the lower holes for the injectors on the pasenger side were machined a little to big. There was an audible hissing noise under the engine bay and a little squirt of brake cleaner confirmed the problem. But it idled very smooth, and you couldnt tell anything while driving. But looking at fuel trims and throttle percentage at idle, I could definately see a problem.

Does it drive smooth cruising at lower RPMs or is it just at idle? You've had the blower on for a while I thought, has it always done it?
A smoke machine would help find a vacuum leak, but I've always just used a little brake cleaner. They do come in handy for finding EVAP leaks too, but thats another story

The miss is pretty small. If the car hadn't died a few times I wouldn't even worry about it anymore. Small enough to not register?

I've had the blower on for about 4 months now. Drives great, even at low rpm. Just will die and kinda lunge at barely any throttle after having tapped on the throttle.

I installed my catch can and breather just for the hell of it.

[PQ]

Originally Posted by anthonyj9h

im telling you man check your lifters.....or do a compression test just so you know its not mech and not chasing ghosts

I wonder if I can rent a smoke machine. Saw some youtube vids. OMG, how easy is that?

Also, I wonder if the smoke residue is harmful to the blower?

[anthonyj9h]

Originally Posted by PQ

I wonder if I can rent a smoke machine. Saw some youtube vids. OMG, how easy is that?

Also, I wonder if the smoke residue is harmful to the blower?

lol if its good for the cats im sure it will be fine for the blower

[PQ]

Originally Posted by anthonyj9h

lol if its good for the cats im sure it will be fine for the blower

I can't find a smoke machine for rental.

And they want 700.00 to 900.00 to buy one. Obviously out of the question.

I'm gonna have to take it to let some shop monkey do it whilst being charged by the hour full mechanic rates.




Imma just put some propane all over it first.

[anthonyj9h]

Originally Posted by PQ

I can't find a smoke machine for rental.

And they want 700.00 to 900.00 to buy one. Obviously out of the question.

I'm gonna have to take it to let some shop monkey do it whilst being charged by the hour full mechanic rates.




Imma just put some propane all over it first.

damn that rediculous id be too........LMAO at the propane thing

[PQ]

Originally Posted by anthonyj9h

damn that rediculous id be too........LMAO at the propane thing

No, for real. Propane torche is safe and already a gas and works the same as break cleaner or starting fluid. I'll try it. The starting fluid just didnt' aerosol like it used to and the leak I'm looking for is small so already in vapor form it should be better.

[anthonyj9h]

Originally Posted by PQ

No, for real. Propane torche is safe and already a gas and works the same as break cleaner or starting fluid. I'll try it. The starting fluid just didnt' aerosol like it used to and the leak I'm looking for is small so already in vapor form it should be better.

good improvision......i thought you were going to propane the tech and take his smoker..........at least thats my idea

[PQ]

Originally Posted by anthonyj9h

good improvision......i thought you were going to propane the tech and take his smoker..........at least thats my idea

Well, I may also similate a smoke machine and just listen for air? With the car off it would be easier to hear. Plug the intake and force compressed air into the vacuum hose and listen.

[anthonyj9h]

Originally Posted by PQ

Well, I may also similate a smoke machine and just listen for air? With the car off it would be easier to hear. Plug the intake and force compressed air into the vacuum hose and listen.

lol how are you going to hear over the compressed air then? car isnt that loud is it? any ticking?

[PQ]

Originally Posted by anthonyj9h

lol how are you going to hear over the compressed air then? car isnt that loud is it? any ticking?

Maybe with the motor off and shooting the air into the brake booster hose it may produce a hissing that is disticnt enough to pinpoint. I'll just have to be carefull not to pressurize too much. But I can turn down my compressor to only allow 10 psi out.

Ya,,,,,, no,,,,,,

[Russell James]

I wouldn't do that. I've never heard of that as a diagnostic method. If you suspect a vacuum leak there are several methods besides the smoke machine. You can wave a small propane torch (no flame) around everything and watch for an rpm change. When you wave propane past a vacuum leak, the rpm will usually go up.

You can also use a mechanics stethescope poking around suspicious areas. You will hear a distinct hissing sound near any leak.

You really need a scanner though to make sure things like the MAF and O2s are reading correctly. Do you have anyone nearby you could swap MAF sensors with? Or possibly put the OE airbox back on just to see if the MAF position is affecting it.

Leaking valves can also give an erratic idle. Wouldn't hurt to have a leakdown test done just to make sure all the valves are sealing. Or just put a vacuum guage on it and make sure it has steady vacuum at idle.

[PQ]

Originally Posted by Russell James

I wouldn't do that. I've never heard of that as a diagnostic method. If you suspect a vacuum leak there are several methods besides the smoke machine. You can wave a small propane torch (no flame) around everything and watch for an rpm change. When you wave propane past a vacuum leak, the rpm will usually go up.

You can also use a mechanics stethescope poking around suspicious areas. You will hear a distinct hissing sound near any leak.

You really need a scanner though to make sure things like the MAF and O2s are reading correctly. Do you have anyone nearby you could swap MAF sensors with? Or possibly put the OE airbox back on just to see if the MAF position is affecting it.

Leaking valves can also give an erratic idle. Wouldn't hurt to have a leakdown test done just to make sure all the valves are sealing. Or just put a vacuum guage on it and make sure it has steady vacuum at idle.

Well, I confirmed with Mike at Vengeance that the fuel trims indeed showed a vacuum leak. Which is why he did a quick search for one.

Much like a smoke test, the nozzle will be hooked to the end of the brake booster line, I can set my compressor for 10 psi output and leave it if I have to and if that doesn't work, the brake booster line is long enough for me to get around the engine bay as I blow air into the line. I can light a cigeratte OR some other form of smoking object and put it up to all of the areas that would leak.

No? You don't think it could work?

I'm gonna do the propane test too, but I think the other could work just fine. It's the same priciple as the smoke, but without the smoke.

[PQ]

Ok. Did some things tonight.

First, I used propane AND starter fluid in abundance. Sprayed everything imagineable. Nothing. Of course, I also took a line loose and sprayed BOTH straight into the lines and nothing. Supercharger maybe? At any rate, the leak did not make it's self known.

Finished the lines on my catch can. Drove the the store and the car died twice.

I did a few interesting things.

Pressurized the intake system. Much like a smoke test where the system is pressurized with smoke and you can see smoke coming from a leak, I pressurized it with regular air and tried to use smoke from a cigarette to find an air leak. Was hard to get the cigarette in most places so I turned up the air to allow for 20 PSI to go in. I heard and found a leak at the place noted in the picture below where the red 'x' indicates. It's behind those coolant and heater lines where the vacuum line ends and hooks down right next to the fuel line. Same type of connection. I heard the air and so I felt down there and felt the air too. Didn't hear it anywhere else.

So my question is what is that line for? What is that solenoid looking thing the yellow arrow is pointing to? The vacuum line comes out of the blower and goes into the bottom of that solenoid thing and out of the top come that line to where it connects down by the fuel line where it's leaking air.

HOWEVER. I plugged that line off at the solenoid thing and the car did NOT improve.

Does this tell us anything?

Oh, ya. When the system pressurized fully to about 20 psi, that solenoid thing started humming pretty good.

So? Am I an idiot?

Is this the EGR valve?

[anthonyj9h]

the red x is your heater hose that goes to the water pump.....also if you had and egr prob you would get a code for it...............anddddddddddddd we need a better close up if you can plz