Car won't hold idle. Ready to rip hair out. Video included.

[Grocery Cart]

Car is a 1993 240sx with a 1995 ka24de. Has s13 dohc temp sensor, intake, wiring harness, distributor, ecu, and maf.

Starts right up, revs to around 4-5k for a second or two and will stay there if i feather the throttle. Once it starts to go down it will just die. No sputtering, or misfire. Just straight dies.
All vac ports are capped except the necessary ones, fuel filter, new PCV hoses, egr blocked off, IACV cleaned, new plug wires, new plugs (although they may be slightly dirty from running rich a few times prior), timed it, new-to-me known-good IACV and iacv gasket, new-to-me known-good TPS set to .47, I've tried two different mafs. It seems like a vacuum leak but I've gone over it multiple times and didn't see any unattended vac ports.

Video shows me starting it with the maf unplugged, letting it idle, then when I plug the maf in it dies immediately. Didn't even have time to go into the car to show the tach.

Any advice is greatly appreciated.

Ytkkf4CuCpc

[Kingtal0n]

You have an enormous vacuum leak. Do a boost leak test to isolate it.

Its pretty big so, you might be able to clearly feel it somewhere obvious. intake manifold, brake booster, two places to start. Try clamping/plugging the IACV.

You can be sure that it is between the intake valves and throttle body.

[Grocery Cart]

You have an enormous vacuum leak. Do a boost leak test to isolate it.

Its pretty big so, you might be able to clearly feel it somewhere obvious. intake manifold, brake booster, two places to start. Try clamping/plugging the IACV.

You can be sure that it is between the intake valves and throttle body.

What makes you so sure it's between the intake and tb? Just curious

[Kingtal0n]

the demand for air applies at the intake valve. Imagine running the engine with no intake manifold, it would rev up as high as it could and explode magnificently.

So what stops the air , limiting RPM?

the throttle body.

[omgosh]

Mega vacuum leak, or stuck open idle solenoid and warm up valve.

All the air used to idle the engine comes through the big hose off the intake pipe. That hose feeds the idle valve/solenoids. If you crimp the hose, theoretically the engine should have no more air to idle, and will stall. If it continues to run, it is because it is drawing air in from somewhere else, like through a vacuum leak in the manifold, or maybe stuck/broken throttle plate with as much RPM as you are getting.

[Grocery Cart]

Mega vacuum leak, or stuck open idle solenoid and warm up valve.

All the air used to idle the engine comes through the big hose off the intake pipe. That hose feeds the idle valve/solenoids. If you crimp the hose, theoretically the engine should have no more air to idle, and will stall. If it continues to run, it is because it is drawing air in from somewhere else, like through a vacuum leak in the manifold, or maybe stuck/broken throttle plate with as much RPM as you are getting.

what hose are you talking about?

[omgosh]

http://i.imgur.com/qYLLDPa.jpg

[beatfishe]

good,You can be sure that it is between the intake valves and throttle body.thankshttp://goo.gl/bylhmn

[Grocery Cart]

good,You can be sure that it is between the intake valves and throttle body.thankshttp://goo.gl/bylhmn

I've got that line connected and it seems like it's good all the way to the iacv with no cracks or leaks.

I just got back from inside and used half a can of brake cleaner trying to listen for a change in idle and nothing. I also tried adjusting the distributor full clockwise and counter clockwise (with the maf unplugged) and no change, plugged in the maf after rotating both times and it did just like it normally does; revs to 4-5k then dies.

[Grocery Cart]

Update: I reread omgosh's comment and decided to go outside and plug the iacv hose with my finger. car dropped to 1k and idled smooth. confirmed the vac leak and made it suck harder aka louder. It's between the upper and lower intake mani between the second and third runner.

[Bushido]

If i were you, I would have posted thread this in the Tech section...
I would also pull the intake manifold, clean everything, replace the gaskets, and reconnect/replace the vacuum hoses you "capped".
Doesn't look like your motor is turbocharged, so there is no reason to cap those vacuum lines.
Without a tune your car will run rich/worse just capping lines.
Rubber caps will eventually fail and cause problems like you are having now.
If you want to eliminate them in preparation for turbocharging, weld them shut.

[Grocery Cart]

All gaskets have been replaced, I removed the egr and carbon canister so all of those lines were useless and didn't go anywhere anyway. From my understanding you only need the for, brake booster, pcv, and iacv hoses. Which are all connected properly (except the pcv apparently if you read my last post) and the remaining lines are caped off. I would prefer to weld them, but I do not have access to a welding machine so rubber caps suffice my needs.
Thanks.

[Bushido]

Just know that your car will run rich (worse) without tuning to compensate for the removed EGR system. No point in removing EGR system unless you are turbocharging and tuning.

http://zilvia.net/f/showthread.php?t=192553

[xilovelsdx]

Sounds like a tps sensor to me.