Is my intake cracked?

[Embalmer]

I've been fighting an intermittent lean issue mainly on decel in a higher gear. I've been told by tuners that my datalogs indicate a vacuum leak. I decided to pull the intake for a closer look. I spray a 100 wet shot, so I'm not doubting that there's an issue here. You can see in the 1st pic there seems to be some sort of debris in the seam.

Does anyone have a similar picture I can compare mine to?

 

[chuck@evoperform]

Looks cracked but hard to tell. Nitrous and plastic manifolds dont go well together when some of the fuel/nos mix ignites in the manifold. If you have access to a smoke machine (produces "smoke" vapor similar to a smoke machine in a club, but uses air pressure from an air supply) you can seal all the ports but one with tape and see if you have any leaks from the suspect seam(s)

 

[God]

A smoke machine is a good method as suggested.

If you don't have one, you could try taping up all the openings with duct tape and pressuring the manifold through one of the ports with a blow gun and very very low pressure compressed air. Spray a solution of soapy (dish detergent) water on the suspect area and check for bubbles forming.

 

[one eyed willy]

1) manifolds are a dime a dozen.....just get a new one

2) if you really wanted to, you could put it back on and just spray some starter fluid on that crack while its running and see if the rpms jump....if they jump, then that means for sure its cracked.

3) refer to #1

 

[AbdullaGT500]

This ^. Spray some carb/choke cleaner on it while its running and see if changes the idle at all.

 

[kevinatfms]

C&L or FRPP

 

[Embalmer]

Just to follow up with this thread, I got another intake and installed it, and my issue is gone. Upon high vacuum, air would get sucked into the intake through the (2!) cracks I found and the air/fuel and trims would go wacky, not to mention my idle was way off. I think a C&L intake is in my future so I don't blow up anymore!

 

[bradleyem]

2) if you really wanted to, you could put it back on and just spray some starter fluid on that crack while its running and see if the rpms jump....if they jump, then that means for sure its cracked.

This ^. Spray some carb/choke cleaner on it while its running and see if changes the idle at all.

Winnar!!!

It's amazing how many people that I surprize with this old school trick for finding a vacum leak....

 

[555]

Just to follow up with this thread, I got another intake and installed it, and my issue is gone. Upon high vacuum, air would get sucked into the intake through the (2!) cracks I found and the air/fuel and trims would go wacky, not to mention my idle was way off. I think a C&L intake is in my future so I don't blow up anymore!

Glad you got your issue resolved
What does your car run in the 1/4
I have very simmilar mods and weather is still crappy here for me to run mine

 

[Embalmer]

Just a quick follow up, I've been experiencing a new issue recently where my air fuel ratio is about a point too lean. It fluctuates a bit more than what was normal between 13 and 15 and at WOT I'm at 14.5. I also have a bit of bucking on decel. Any ideas?

 

[one eyed willy]

Just a quick follow up, I've been experiencing a new issue recently where my air fuel ratio is about a point too lean. It fluctuates a bit more than what was normal between 13 and 15 and at WOT I'm at 14.5. I also have a bit of bucking on decel. Any ideas?

clean your MAF recently?......sounds LOT like the same issues i was having coming back from the track not too long ago, felt like the car was going to die at each red light......was also showing very lean (turboed=scary situation)......

asked the same questions......was told to clean the MAF and it worked!

 

[07 procharger]

check your plugs....are they showing lean? (white porclin?)sp