1993-VG30E-GXE

So here was before and after:

BEFORE:
-Rough idle, 1 dead injector - car would still drive, but drove rough and less power but didn't stall

REPAIR:
-Repaired 1 injector with pink top yellow dot.
-Forgot to buy lower intake manifold collector gasket so re-used previous metal one (New one installed June 2008) - Upper gasket is new
-Attempted to do leakdown test with rail assy out and intake off - wouldn't work. Somehow the rotor arrow position would move backwards as soon as I attached the 90PSI air supply - something very strange. But air would espcape out the injector holes.
-All hoses are connected properly. Everything is back in place how it was originally.

AFTER:
-Car immediately goes to 2000 RPM and idles smooth, as if that previous rough idle is gone - injector must have worked - then after 1 minute it started going low in RPM and getting really rough - and stalled out
-I can maintain the car running if I hold my foot on the gas and keep it at 2000RPM or higher. As soon as I let go, it starts the 'coughing' thing where it is so close to stalling out, it didn't stall every time but would keep coughing and with foot off the pedal the RPM drops to about 500. Now when I subsequently started it, it doesn't idle at 2000RPM for the 1 minute - it starts to stall out after 10 seconds or so.

Any assistance appreciated, i'll do the diagnostic you suggest during the day tommorow. In the meantime tommorow i'll finish putting the suspension in...want to get this car back on the road hopefully this week.

CapedCadaver

iTrader: (8)

@ reusing gaskets

check for intake leaks. if enough of a leak is present the car can stall. for example if you pull the iacv tube off the intake tube at idle the car will stall.

1993-VG30E-GXE

Here's an update caped - I went out to start it, it drops again low and starts chuging, and the RPMs go up and down up and down...the needle bounces from 0 to 500 0 to 500. This time, it wasn't stalling, it would keep doing this cycle type thing, but about to stall - and it seemed like it could keep going like that without stalling.

What type of test can I do to check for intake leak? Pinch the blow-by hose to listen for engine speed rise? I'll try spraying soapy water around the lower gasket and see if that's leaking. Is the lower gasket that critical that it could produce a stalling situation like this. Some mechanic at a garage told me the metal gaskets are re-usable. The non-metal ones aren't he said.

To sum it up -basically, the VG30E is hunting.

CapedCadaver

iTrader: (8)

just replace the gaskets with NEW gaskets and see if that helps. asking and asking until you get an answer that satisfies you does nothing to change the fact that you cheaped out on the job in the first place.

1993-VG30E-GXE

Is that lower gasket critical to create an air tight seal? Like a vacuum? The upper gasket is new - and for you to say 'just replace the gaskets' that's more work than it sounds. Is there any other tests I can do in the meantime while I order the gaskets.

CapedCadaver

iTrader: (8)

everything is critical. it's like a chain... one weak link and the whole thing is useless. anywhere that air can sneak in past the MAF is a problem. just fix it. you already know it's a problem.

LvR

As Caper already said - if you know the gaskets are suspect, do what you should have done in the first place and replace them - no matter the effort - you knew what was involved to start with.
As I said in your other thread there is a basic knowledge of the combustion process required as well as a general knowledge of internal combustion engine mechanicals .................. what you experience is nothing strange at all - if you pressurize a cylinder, the top of the piston exerts a force on the crank via the piston and conrod ............... and that force will try to rotate the crank if there is even a small deviation from TDC for that piston ............... see my warnings in your other threadIf thats the case you either have a really screwed-up motor or have not understood/followed your "reputable" leakdowntest guage manufacturer's recipe - the injectors and their mounting holes are located external to the combustion chamber so they cannot possibly highlight or in fact experience anything during a leakdowntest ................... I don't know where the air comes from that is escaping there, but can only point you to my earlier opinions in your other thread.

1993-VG30E-GXE

Ya bud, i'll do that - bloody 4 dollar gasket. I'm going to order like 5 of each so I don't run into this problem again.

biggz2332

iTrader: (5)

When I had did my injector b4 the same thing happen although I had new gaskets I just had for got to put back two hoses behind the manifold I think you have a vacuum leak thats causing the idle, I assume air through a gasket would cause funny Idle too but not that bad...............but check hoses again and change that gasket

nitrous360

You have luck like me, if I don't do it by the book it bites me every time. In the end it just isn't worth it.

1993-VG30E-GXE

Yup, your right. This time I really did forget to order it though. Stuff like gaskets i'm going to order a small number or else you end up paying shipping if you just suddenly need one for a job. And I hate going to the dealer here...huge rip. What upcomming repairs do you have.

maximaman1313

not replacing stuff as i should has me diggin into my ve to replace the knock sensor harness when i should of replaced it 5 years ago when i replaced the sensor.and now im replacing it on top of all the stuff to get to it. oh well, live and learn?

nitrous360

Well I don't think you want to ask me that question. I named my Max a while back. I called her Mad Max. But, now after numerous problems/money sunk into this car from hell, I call her Bad Omen.

In the past year or so I've replaced, complete exhaust besides manifolds, tranny rebuilt, complete brakes besides master, every injector, air intake, battery, radiator, water pump, timing belt, plugs/wires/cap & rotor, A frames, outer tie rods, all hoses (vacuum/cooling & fuel), and more. I can't remember right now.

1993-VG30E-GXE

That's alot of stuff in 1 yr. Did you rebuild the RE4F02A yourself by the way?

nitrous360

No, I had a friend who primarily rebuilds tranny's do it. I wanted to do it right and not have any issues. Pulling it out once was enough for me.

ColombianMax

iTrader: (7)

I shall call that an "Alex V", man o man did that guy enjoy reusing gaskets!

GRNMAXDMON

iTrader: (1)

well, my time came to swap out a dead injector in my car after about 10 years of owning it. well, i took the upper and lower intake apart to get the fuel rail out with injectors and apparently none of my injectors have the damn dot!!!??? its pink but no dots. WTF? went to the dealer and just ordered one and i think its the one with the yellow dot. what is the big deal with these DOTS? why can't one work for all?

GRNMAXDMON

iTrader: (1)

damn, whatever happened to Alex_V???

Greeny

iTrader: (43)

got banneded for scamming..

GRNMAXDMON

iTrader: (1)

nice one. so Greeny you think you can help me on my situation with whole dot on the injectors. read my post above.

DanNY

iTrader: (14)

you can do a smoke test. i have a this gizmo that will pump smoke into any port.
push the hose into the port and press the button. it injects a cloud of smoke into your intake or whatever port and if you see smoke leaking out...you've found your leak.

i have the same idle problem as you...total PITA and no time to work on it.
If you REALLY have to reuse a metal gasket next time throw some RTV on it. not a full bead put a smear on it should be enough.

i think i found one of my injector rings to the lower IM is leaking...ahhh crap.

Greeny

iTrader: (43)

http://forums.maxima.org/3rd-generat...or-colors.html

Post #12 and 14

The dots are painted on by a paint pen from the factory that made them originally, the paint wears off after the years..

GRNMAXDMON

iTrader: (1)

so, it wouldn't matter if i got either the yellow or green?

Greeny

iTrader: (43)

most likely no, it's not going to make any difference..

GRNMAXDMON

iTrader: (1)

well, im pretty sure that im getting the one that has the yellow dot so hopefully it will work for me.

G3Karl

iTrader: (1)

My guess is that you messed up one or more of the rubber gaskets that the injector "sits on" located in the lower intake manifold. I did this once and had to redo it again. You may hear a loud sucking noise and if so, then thats your problem.

maximaman1313

i believe those are called the insulators. I dont think they need to be replaced everytime

1993-VG30E-GXE

It was the gasket guys. In fact, I think it was the upper gasket actually, that was actually a new one....it got bent to hell in the mail the way they shipped it, and there were these sharp bends in it. I tried to straighten them out but it may have not worked.

Anyways, when I removed that top gasket, it looked like there were these marks near these bends......and a few times I noticed air or steam or I don't know what maybe smoke shooting out the front where those bends were....when I started the car.

New upper & lower gaskets and it runs fine now. But I'm having trouble with this oil seal. Don't want to damage it then wait another 2 days for the dealer and waste more money on another seal.

1993-VG30E-GXE

Good call too. I actually replaced that lower insulator for the new injector. Probably should have done all of them but I didn't think of it.

Here are the parts by the way for the VG to refresh anyones memory:

INJECTOR INSULATOR TOP
INJECTOR O-RING SEAL UPPER
INJECTOR O-RING SEAL LOWER
INJECTOR INSULATOR BOTTOM
INJECTOR CAP SCREW (16) M5X16 8.8 CAP SCREW FULL COARSE PLAIN
INJECTOR
ENGINE OIL TO LUBE O-RING
ANTI-SEIZE
FUEL RAIL ASSY-->INTAKE SOCKET CAP SCREW (4) M8X20 12.9 SOCKET CAP SCREW FULL COARSE PLAIN
M8 LOCK WASHER (4)
M8 WASHER (4)