I picked up a plenum spacer from riverside infiniti but one of the bags was split when I got the box home so some of the parts never got packed into my box. I learned a very valuable lesson through this discovery: check your parts before doing the install. Basic, but I was arrogant and it stung me.

On to the story,

Installed the iso thermal portion of the motordyne plenum spacer on the underside of the lower plenum. Greased it up with motor oil like it recommended to promote better seals.

Reinstalled all other hardware completely stock because I was missing three of the middle bolts that have to be larger to put the new washers on. Torqued everything to spec, connected all the hoses, put my intake back in. Reconnect the battery. I never installed the plenum spacer, only the iso thermal insulator part that goes below the lower plenum.

However, I start the car, it revs up, then immediately sputters and dies. I go back to the drawing board check all my connections, then thought "maybe because the ECU got reset I have to rev it a bit to teach the car." I did this and I thought I was successful because I pulled out of the driveway. When I made it down the block and clutched into neutral at a stoplight, the car again puttered and died. I only made it back by restarting the car at every stoplight (couldn't U near my house) and reving the crap out to make sure it never reached idle.

As best I can tell, everything is connected. I can see connected 4 vacuum hoses (one on the left side of the plenum, 2 on the sides of the intake butterfly area, there's one underneath the butterfly that I also connected) on the plenum, one vacuum hose on the bottom of my z tube. I have connected both the plug into the intake butterfly assembly and the MAF on the intake tube.

Does anyone have any ideas? I wouldn't feel comfortable driving it all the way to the shop because there are some major intersections even though it's only a few miles away. I'll have it towed tomorrow morning if I can't get this fixed. Really crappy way to end the weekend =(

 

I just did mine yesterday.

Check to see if the rubber part of the oil fill isn't stuck between the plenums.

OEM plenum gasket still intact?

Are the electrical connections securely in place (MAF & Throttle Body)?

These may help.

 

Rubber I had to pull out while I was reconnecting. Had torqued the bolts down but redid afterwards.

The OEM gasket was a little bent but nothing major, everthing appeared okay and it looks like a nice tight seal between the upper and lower plenums.

I have checked both the connections and they seem fine. Those are the only two I remember disconnecting, as long as there isn't a third I'm forgetting about.

Watching the vids now. I'm wondering if this is a problem with the iso thermal thing I installed, or if I just reconnected something incorrectly when I was putting it all together (this is probably more likely but I can't rule out the first).

 

I guess it's probably vacuum leak somewhere. Probably going to have to end up towing it.

 

^thats what i am thinking. its been so long since ive did mine i cant really remember. oh one more thing...did you make sure none of the rubber or plastic things inside the plenum didnt fall into the plenum? i had that happen to me when i was installing mine...

 

Definitely double check your vacuum seals

 

When I did mine I forgot a to connect a small hose up by the top of the engine between the car a hard to miss hose. I also had spuddering like you had.

 

Did you move the throttle at all while it was disconnected? Might have to do a throttle position reset. Not sure exactly how, but you'll find it if you search.

 

Prolly need to re-calibrate/reset the TB. Try this before you have it towed:
http://www.motordyneengineering.com/manual.pdf
Look on 'last' page....

 

Thank you all for the helpful replies. I decided I'm going to give it today and tomorrow to try and fix this before I tow it. I have a buddy who can give me a ride to work these days.

I'm going to reseat the plenums today and see if I missed something along the way. I never intentionally touched the throttle body butterfly but it's possible I knocked it.

It seems more like a vacuum seal somewhere. I'm going to go all the way down to the lower plenum to make sure I didn't seat the iso thermal gasket incorrectly.

A lot of people I've talked to off the forums say that the gaskets can only be used once and that I might be leaking from that. I find this directly contradictory to the motordyne manual and all videos that say you CAN re-use the gasket. Either way I don't see how that would be causing enough of a leak to completely prevent my car from idling.

This stuff sure is frustrating sometimes, but at least I'm learning. A lot of people I've talked to keep asking me "why would you want to put a performance mod in there when your car works perfectly fine?" I keep saying to myself 'why do people climb Everest? Because it's there.'

 

That's what I tell them, too. Good luck, buddy. Hope you get it fixed. When you do, do us first-timers a favor and tell us what the problem was. I just got my G and spending these first few weeks researching and saving up before I start doing any real modding. The plenum spacer is definitely on the list of mods-to-do, so in case I run into the same issue, I'm hoping this thread will show me the light. *crosses fingers*

 

Figured it out. Somehow the gasket had gotten folded over at one point. The thing is completely shot but I was able to bend it close enough to seal the space between the plenums. It will get me to work for tomorrow when the parts come in ups that were missing from my motordyne pack.

I think I was just frustrated last night from searching for the damn missing parts for like an hour and a half to make absolutely sure I hadn't dropped the bolts in my garage, the only place they'd been besides the ride home. I knew deep down that I wouldn't find them but I had to give it a go.

 

OEM gasket. That was my first question in my first post.

You don't have to reuse the OEM gasket if it's completely hosed.

 

Sweet. Two things to double check -- hoses and folds. :P

 

When I open the thing up again, is there a point to undoing the lower plenum and making sure that I seated the iso thermal spacer correctly? I don't feel like anything is wrong with it but now I'm second guessing everything I did with this mod.

If I cleaned off the engine block a little with a rag, oiled up the iso thermal spacer and put it in between the guide bolts, then put the lower down there's really nowhere I can go wrong, right?

I guess a more important question would be if I take off the lower to check, does that mean I can't reuse the iso thermal gasket?