One last try (under plenum job)

[cccpman]

All right, took the plenum off for the 12th time (yea I know) - I just could not find the problem, but it seemed like a vacuum problem (sounds like an old drag racer engine - with no power). Anyways I took a lot of time on this, spent about 6 hours going over every single hose and connection under the plenum and around it too. Yanked them all off, made sure all were new or like new condition without cracks, leaks, or hardening

Eventually, found the nice UFO looking disc (there are two on the drivers side, not actually under the plenum - im sure this could be the leak) was not connected to anything underneath! wiggled it out, looked for where it should be connecting and quite frankly I can not locate it (big head, big hands, maybe just too far to see/reach). Question is how should I go about reattaching this? Is it best to take off the under engine cover and attach from the bottom or to keep fooling around and try to get it from the engine bay? I do not know anything really about why this is a metal hose, unless it is related to brakes or the fuel line, somebody dump some knowledge on me

The only other problem I have after thats solved is the fact that both KS i bought were dead on arrival in the mail or died the 5 miles I drove my car since I had installed them - new ones are being grabbed up as the Infiniti dealer actually had them IN STOCK

Finally, I am considering switching to some generic bolts to bolt the plenum down. I can get the exact same size, put a washer on it and it should work out. The fact that a bolt was broken in there and is impossible to remove really worries me (yep, could not be removed even by the 'professionals' - I have a piece of one of their titanium bits stuck inside a steel bit, stuck inside the bolt. The last guy offered to weld something to it to twist it out... no thanks). I helicoiled the entire system and it works wonders, the strength is FAR above what the car needs, I just want bolts that will do the same (and are not so tempered by heat they are brittle to breaking point)

Oh well, a happy day indeed! Found my problem and in a day or two could be driving the queen again. Wish me some luck this time :PThanks guys!

[elwesso]

There is nothing under the plenum that requires you to remove the engine under cover. i dont know where you came up with that........

in my experience, vacuum leak symptoms generally are something like a really low idle, then you give it some gas and the idle jumps up, especially worse when cold.

im really confused on what you did and how you botched this up. If you need help getting the plenum back on, call me after 1pm EDT (GMT -5). I can guide you through the job step by stem to make sure you get it right. Ive done the plenum enough times to get it right.

Did you just remove the plenum, or did you remove the runners too?

[cccpman]

I stripped it down pretty good, including the runners the last couple times. The part I did not (or at least intentionally) remove is that round disc in the back right side of the engine. Thats why I had a constant vacuum leak. I removed it and pieced it together word for word several times using your guide, and the rest of the times by heart. Actually im down to 30 minutes to pull it off (plenum) and 30 to get it back on (with no broken hoses). One hell of a learning experience at least, I learned what most parts do, their names, and their part numbers

The part that was disconnected, im not sure of its name but it would be nice to get it. Its located right next to the brake booster, there are two round discs, one of which has a steel hose that *should* be connected behind the engine somewhere but was not. In the morning I should have it all running in under an hour. I will take a pic to identify it, knowledge is a good thing and it would be nice to know what it does (also after further inspection it is cracked down the side so I will be grabbing another from a junkyard tomorrow if I find one in good shape)

Under engine cover was just a wild guess, as it was getting dark I discovered this part was not connected, looks like it would be just as easy to connect from under the engine as it would above (if only the hood could come off!)

What could I mess up under the plenum that would cause a very high and erratic idle with a horrible sounding engine? I'm pretty sure not much other then a bad gasket or a part that somehow was removed (if this is not the solution, im grabbing a sound byte - a you must hear to believe case)

Your knowledge and others is the reason I keep working on this car, hopefully one day it will be in the condition it was 18 years ago. Good stuff. Thanks for the reply wess, cant wait to try that ECU out tomorrow

[maxnix]

Don't mess with the lower intake runners too often unless you have new gaskets.

Stick with it. You probably know more about the VH45DE than most new Infiniti techs.

[Q451990]

I can tell you that the parts you're referring to are the EGR valve and BPT valve. Beyond that I can tell you that some pictures of them would be helpful... we could look at them and give suggestions. BTW, Colorado was great... I miss the low humidity already!

Heath