300zx TT dies at low RPM

[3ZsL8r]

I've got a 90 300zx with a tt swap.
Having a few issues with it that I was hoping you guys could help me diagnose because I don't have 3k to just blow on parts for this car. I got it in a trade for a jetta, (should've known something would go wrong, right?)
Alright, here it is.

Driving at high speeds (40+) car does fantastic.
But when the RPMs get low (1000), goes down to about 500, then starts to studder.
Car doesn't jerk or anything, but just studders a few times then dies and all dash lights come on.
My fuel pump seems to be a little noisy, and not the sound of it priming but whiny.
When I turn to hear the fuel pump, it's pretty quiet and sounds week,
Thinking it is that, also the fact that when searching the car I found a brand new one under the passenger seat....

So I went to do this, and holy crap it's annoying to get it. Well, I never actually got it. I got panels off, all screws, etc.
Had trouble with 2 hoses, now I'm stuck on one. It wont come off to save my life.
The one on the very left with like little to no room to grab, won't come off.
Suggestions??

ANy other ideas on what is causing this? IAC? Could it be electrical since lights lights dim right before it dies?

Thanks guys!

[evildky]

I'm going to move the to the propper section but first I'll try and offer a bit of help. Congrats ont he Z unfortunately this particular model tends to very expensive to maintain service and modify, mosty due to the packaging. When buying one it pays dividends to buy the cleanest most stock car you can find and I recomend against buying one thats been swapped, andymore it's cheaper to buy a TT than to convert an n/a especially if you are paying labor, that being said lets see what we can do to help.

when the car dies, I assume this is when decelerating? if so it's typically the aicv, it's on the back of the plenum and likely needs to be removed and cleaned and put back, they get dirty and sticky and no longer move quickly enough to stop the car form stalling when decelerating.

your rough idle could be a number of things, first and formost make sure that the car is in fact idling on all 6 cylinders, it's amazing how well they can run or 3 or 4 cylinders. with the car idling, unplug each cop one at a time and see if it effects the idle, if you unplug one and the idle does nto change that cylinder isn't working. There are still a number of reason's why but step one is locating the effected cylinder(s). Something as simple as a bad cop connector or a bad fuel injector clips can cause these problems, could also be a bad spark plug, bad cop, bad ptu, or even a cracked valve seat.

Feuel pums tend to get noisy before they fail, low fuel levels make them louder as does missing interior panels and insulation.

When removing the fuel pump, sometimes those little screws can be buggers, I've had good luck using a small pair of vice grips, not easy to do but the results tend to be worth while.

The lights dim before the car does becaust the alternator slows down and the voltage drops, it doesn't really indicate anything.

[3ZsL8r]

Thanks for the input! Turned out to be a vaccum leak. The bar that goes across the top of the manifold, 3 bolts on each side, controls air/fuel ratio. Yeah, One bolt was missing. I stayed in the cabin to keep the car going while my brother searched around, plugged, car doesn't die anymore! Fuel pump isn't acting weird anymore (thanks goodness too because I couldn't get 1/3 hoses off. 2 coils are burnt, so cyl 1 & 5 aren't firing. But I believe that's all I need to do now and I'll be set.

You think I would've leanred my lesson from buying these cars.
1st one was a 2+2 TT swap, 5 owners later & 3739493$ put into it it still won't run correctly.
2nd one was a n/a but I blew a heater core and head gasket.
this is my 3rd, and I'm 17 so I'm learning a lot while I'm young!

I'm going to go out now & check the aicv , just to be safe.
btw, if you know anyone selling used coils that still work get on here and say something, maybe we could arrange something.

Thanks!

[t.mcginley.jr]

You think I would've leanred my lesson from buying these cars.
1st one was a 2+2 TT swap, 5 owners later & 3739493$ put into it it still won't run correctly.
2nd one was a n/a but I blew a heater core and head gasket.
this is my 3rd, and I'm 17 so I'm learning a lot while I'm young!

Should've started with something simpler like an Altima or Maxima lol