It's getting dangerous now...my car will "pull", "struggle", "hesitate" at almost any speed, and will often DIE when waiting at a light, or as I'm driving

What I've done so far:
Changed my PCV
Changed my Fuel Filter
Changed my Engine Coolant Temperature Sensor
Cleaned my Throttle Body
Cleaned (sorta) my Idle Air Control Valve

What's next:
Check my Mass Air Flow Sensor
Check my Throttle Position Sensor

What makes me EXTRA mad, is that i can find many others on here with
the exact same symptoms, and NONE OF US can figure this out...

This is getting out of control -- PLEASE HELP!!!

Thanks!
FLO_BOY

Are you throwing any codes?

Could be a faulty Mass Air Flow Sensor? Just make sure that this is the case. It's a fairly, expensive part.

The other day, I received a MAFS code...hasn't repeated itself...
need to check with a multimeter...

FLO_BOY

while you're in there, clean the connectors and make sure the connection is secure.

any fuel smell in the engine compartment when it dies?

Plugs?when did you last change your spark plugs?

No fuel smell...thanks for the input!

FLO_BOY

maybe a year ago...less than 20K miles...
thanks for the input!

FLO_BOY

Make sure you don't have any way for air to enter the engine after the MAF. My car had similar symptoms and it was because the PCV hose the connects to the front cylinder bank developed a gash in it and was letting unmetered air into the engine. Also, like you've all ready mentioned I would check the throttle posistion switch. Good luck and let us know any success.

could be the fuel pump.. my fathers car was doing the same thing, then finally it just went out permanently and never started again. Sounds like it can be a problem with the fuel system as well, which is really broad, i know... but maybe you can get the injectors cleaned, also check the fuel lines for leaks or maybe they are clogged somewhere, good luck

Just in case you need, her a how to.

http://vbxmaxima.8m.com/tps.html

Sounds like a faulty MAF or an intake leak downstream of the MAF.

If air gets into the intake downstream of the MAF it will run very poorly, as you've described. Cheack all your connections, clamps, and bellows between the MAF and TB. Also, check all your intake manifold gaskets, they could be leaking as well. (Ming knows about this with his chromed upper manifold...)

Does the engine have to warm up before it starts acting up?

This will be hard to explain but here we go:

When I check my ECU for trouble codes, the littls screw you turn on my car never stops turning - so basically I could turn it all day long. After turning the screw clock wise, if I don't turn it back (counter clockwise) the same number of turns my car will just die after I start it up - unless I keep the foot on the gas:

So my question is - how careful were you when you checked your ECU for trouble codes? did you over turn the screw? If so you should try turning your ECU screw counter clockwise a couple of turns...

Sorry if that wasn't clear ...