Help needed vacuum leak issue

i have a 99 keep wrangler tj and we put an exhaust manifold on. After complete, the Rpm's red line. Checked both sensors and all hoses. Nothing. Can't leave keep running long enough to find leak. I'm thinking it's in the upper manifold and we've been told that it wasn't seeded properly so we re did the entire job but nothing changed. I'm at a loss. How do we find the leak with RPM's over 4K if we can't leave it running? How do I fix this issue?

 

Welcome! Subscribed for the connection between vacuum leak in the title, RPMs at redline and exhaust manifold replacement.

 

Checked the throttle. The butterfly clip doesn't even move when engine is running. No pinched connections. We think it might not be a solid connection at the upper manifold between the manifold and the gasket. The vacuum leak is happening towards the bottom of the upper manifold. It's just sucking in air. We found a tightening pattern on another thread. Hopefully that will work. If anyone has any other suggestions please let me know. Thanks.

 

Ha! So you're not gonna want to hear this but your intake manifold isn't lined up... it's a pain in the a** but there are two metal dowls that align the intake manifold so it sit straight. Yes everything will bolt up and tighten down just fine and you would never know but it revs to 4K and stays there. The intake manifold is not aligned correctly I promise. Also when you take it back off check and make sure it's not cracked or broken on the sealing surface as torquing it down on these dowls incorrectly can damage the aluminum intake.

 

Wow. I did not know that. Rebuilt a Chevy 327 years ago, and do not remember dowels. But that's a Chevy. Lol.
Good to know. Thanks Smitty Jeeper.

 

We figured out that the California emissions manifold doesn't fit properly. I put the old cracked one on and it ran just fine. I now have to order the original stock part not the stainless steel California piece of crap.

 

Again...WOW. ya have to scratch your head some times. How can a gov't tell you how to do some thing. When they have no fricking idea what it requires, and, what their talking about. I sub'ed this thread. Good to see you worked it out, and it wasn't a major wallet buster. Well, it was time consuming. But it worked out. It's all good???

 

The factory intake works better but instead of redlining, we are now just over 2000 RPM's. Any advice on what we are doing wrong? The only thing we can think of is its still not seeded properly but we've taken it on and off now 4 times. When we tightened the bolts another quarter turn, the RPM's jumped a bit. Anyone know how to find out if we are on the pins? We have spent 3 days on this issue. we have made a little progress from red line to about 2200 rpm, but I want this project over. I still have a lift kit to put on....

Thanks,