Car DIES on startup without gas, rough, low idle... what gives!! 01 QX4

[W O T]

Been having this problem for a while, finally pissed me off enough that I might aswell fix it.

I rolled my 01 qx4 a couple months back and I think its been happening since around that time. If the car is COLD and you start it, it fires up and starts just fine, jumps to 1000rpm, then just dies, no puttering, just drops.

Give it the SLIGHTEST gas and it run just fine, dont even have to hold the gas, just that one second touch on startup and the car runs mint.

THEN

Theres I THINK a low idle, seems to be down in teh 500rpm area, which seems low with my lights on and such. Turn the light and electrical accesories off and it goes to 650ish and runs minty. If the cars been run for a while you can tell at a stoplight, it purrs and is smooth @ 600+ stays there for a second, down to 500 and the car shakes a bit, does that for a second then back up to 600 (maybe not that much fluxuation but obviously enough for the motor to run smoother)

You can physically see the motor shake when the rpms drop a tad.

Was curious if these 2 problems are a quick fix and if they are related, was hoping there was an idle adjustment screw but couldnt find one.... would solve all my problems.

Im also no throwing any codes, havent since I bought the car, which I think is weird, maybe they took the bulb out? Anyway to tell quickly if Im throwing any codes?

Love to hear your guys input on this.

thanks

[tmorgan4]

My guess would be a problem with the Idle Air Control Valve. It basically just supplies some extra air on startup to get the engine up to operating temperature. A common symptom is that the engine won't start without your foot on the gas.

[W O T]

Location? I had that on my Crx, 2 simple bolts and it popped off, buncha carb cleaner and she was golden.

but damn infinities have a million sensors and gadgets and doohickies lol

[SnowSurfLax]

Im also no throwing any codes, havent since I bought the car, which I think is weird, maybe they took the bulb out? Anyway to tell quickly if Im throwing any codes?

When you start it, the CEL should come on for a couple of seconds to let you know it's working and should then turn off if everything is fine. If it doesn't turn on when you first start it up, then they pulled the bulb or its out.

[tmorgan4]

The IACV is attached to the intake plenum. I'd have to take a look to see if it's accessible while the plenum is installed...though. It's a square, 4 bolt pattern.

[W O T]

bulb must be pulled, cause it sure as hell dont come on!

Would love some more startup info on my problems though

[W O T]

id love to know how to raise the idle on this thing, Im sure that would make it start up just fine and obviously idle smoother

Anyone got any advice?

[tmorgan4]

The IACV can be adjusted once you find it. There's a flathead screw to adjust how far it's open. I want to say that turning it clockwise will raise the idle.

[W O T]

I see a few mechs attached to the intake manifold from what I can see by just glancing, I see no adjusting screw though, anyone know exactly where it is on a 3.5?

[tmorgan4]

Damnit....didn't realize you had a 3.5. For some reason I always assume that everyone with this generation Pathfinder has the 3.3L. I'm not familiar with the 3.5 but looking in the FSM should point you to the IACV.