Nice...happy to help!

 

And the answer was ...
I strongly suspect it was the o-rings/grommets at the intake manifold injector ports. I replaced all those. At the same time I replaced the gasket between the collector and manifold. I made sure both pieces were super clean and this time I elected not to use the RTV. I'm also sure that I originally over torqued the bolts mounting the collector to the manifold. So I fixed that too. Nevertheless, I would bet the real fix was the o-rings/grommets at each injector port.

Thanks for all the help!

 

Thanks! Great video. The grommets certainly make sense given where I was spraying the brake cleaner. I think tonight I'm going to try a smoke test. I was thinking it would work to block all the intake manifold ports and run a tube down one to introduce the smoke. Maybe that will identify the grommets as the cause.

 

I vote it is the grommet under the fuel rail. The injectors themselves have o-rings that seal the fuel from leaking down...but under the fuel rail is also a grommet that seals the fuel rail to the manifold. A leak there will give you an air leak.

I used o-ring rebuild kit from Beck Arnley on Rock Auto and it came with the fuel rail grommets as well as injector o rings

 

Is there any further diagnostic I can do from this point of disassembly? I'm not sure how to use my little smoke tester effectively at this point. I will say the Collector seemed to be nicely sealed to the top of the intake manifold.

 

It looks like the #6 fuel injector connector is missing a chunk of plastic. I know when I was putting them all back on I got the nice healthy click from each one.

 

Do you replace gaskets everytime you separate two parts? I'm thinking about the gasket between the SC and the Collector as well as the Collector to the intake manifold.

Thanks for you patience with the newbie!

 

Assuming the SC uses a steel gasket like the normally aspirated it shous.ld be put in dry. That said, you should be fine if it was torqued to spec, but it is a pain to remove RTV products if you have to go back in. Especially on the machined aluminum parts since you have to be careful not to put any deep scratches on the mating surface.

The smoke machine is a good idea and might do the trick in tracking the leak down. It is definitely worth a try.

 

Thanks for the reply! I did use a new gasket. I wonder if I made a mistake by spreading liquid gasket - The Right Stuff - on top of it. (Saw that in the YouTube video

and figured I would follow his example. That video - 2 actually - show a detailed replacement of the ks in a SC Xterra.)

My plan this afternoon is to make a smoke tester as shown here -

and see if I can find the leak.

 

Not normal. You likely need to replace the grommets/seals that the injectors seat in or possibly it's the gasket on the bottom of the intake/SC. Did you use a new gasket when you put it back together? Either way, you're running lean due to a vacuum leak. Given the age, you may want to replace both. Pay close attention to the little black spacers for the fuel rail. They'll be brittle and will break easily (I had to replace mine due to breaking one).