Nmax92

Can a broken upper and/or lower intake gasket cause stumbling and hesitation?

mikekantor

iTrader: (5)

Yes because you would have a vacuum leak, it would be quite loud and noticeable if that were the case.

Nmax92

I figured to as well, I needed confirmation on that. thanks for your help

Josh

iTrader: (5)

If you pinch or tear one of the 6 large rubber seals that the injector rail sits on it can cause the same thing, and yes is it very loud, so you might check those too.

Hectic

iTrader: (20)

Awhile back I went to the dealer to pick up one of those plenum gaskets and part of 1 or 2 of the rubber seals was scratched off, I asked for a different one and the parts guy laughed and said it wouldn't be a problem. So I told him I wanted a different one, then he went and got one for me.

Nmax92

installed the gaskets as per the order in the chiltons manual and to torque specs. I'm still having the same problem. When the car idles, the needle on the tach sometimes dip from 700 to 500 and back up then it settle at 650-700. The car feels like its choking. I checked all the vacuum lines,change the ones that were bad, but no effect. I'm pissed off now because this is 2 days I've been working on the damn thing.

BenStoked

iTrader: (7)

starting to sound like injectors...

Nmax92

the weird thing is that before I started the work, the car was idling very smooth. not a vibration. I heard of someone saying to put a screwdriver on the injector and listen for any ticking, I did and there is ticking on all six.

Josh

iTrader: (5)

5-700 sounds about right where it should be. Do you hear a loud leak in the engine bay? Do some basics (if you haven't already) fuel filter, test out the injectors, etc.

internetautomar

iTrader: (30)

to the OP
the idle is within normal range but it's not smooth is what I am gathering from you.
Clean the IAC. if that doesn't help then if you want to start looking for vacuum leaks use a small propane tank with a hose (carb cleaner works too) and slowly spray around areas of the intake and see if the idle smooths out at any point. If it does, then you found the location of a vacuum leak.

Nmax92

I'll try that method tomorrow. I'm drained. thanks guys. I'll let you know if it works or when I'm sending the car to maxima heaven.

internetautomar

iTrader: (30)

this is not something to send it off for.
I've seen much worse things resurrected.

CMax03

iTrader: (3)

there are alot of air leaks possible on a VG30E, Not only the lower manifold to head gasket but, the lower manifold to lower plenum adapter plate, the lower adapter plate to upper plenum and 2 more spots, fwd of the throttle and aft of the throttle plate. Break out a hose to listen for any air leaks around the intake system!

CMax03

iTrader: (3)

what exactly did you do, I'm curious?

Nmax92

I had a loose clamp on the right fuel hose near the EGR valve. so I had to remove the planum and the adapter plate. so I decided to change the gaskets. the one for the plenum and the adapter plate. How many vacuum hoses does the VG have. I checked them all or am I missing some?

CapedCadaver

iTrader: (8)

which exact lines did you check? looking at it from above... there's one on the top left corner, one on the top right corner, one big one in the back center, 2 small ones under the throttle body on bottom, one on the bottom right, and then the ones leading through metal tubing to the EGR and Powervalve solenoids, the ones leading from the tubing to the egr valve, the ones leading from the metal lines to the powervalve surge tank, and i think that's it.

Nmax92

Max back to normal guys thanks for your help! It turned out to be those pesky vacuum hoses, the smallest ones.