starting problem help please
 

okay i have 13b 87 rx7 my engine starts but it dies unless i have my foot on the gas pedal.
first i thought it was the injectors because when i bought the car the guy told me the bottom two injectors was disconnected and i needed new injectors.i bought new injectors the car starts but doesn't stay on. i think its a vacuum leak or maf sensor problem.
some one told me it can be my tail pipe because i have no exhaust system what so ever
idk what it is.but its gives me alot of head aches some one help please.

There is no exhaust at all? My guess is the neighbours love you!

Starting and stalling could have many causes. Since can keep it running with the throttle, we can assume the AFM is plugged in.

Is there an RPM you have to keep it above or it will stall? Or will it still run all the way down to 700 RPM or so and just die if you let off the throttle?

Depending what the previous owner messed with (probably everything!) you likely have to start from scratch in setting up the idle and other adjustments on the throttle body.

Pressure sensor plugged in?

when i start the car i keep the car at 4000 rpm as soon i let go of the gas dies quick less then a second.
i am missing a vacuum line from the throttle body but idk when it goes . its the middle one(the second one towards the top.
the previous owner didn't know what it was so i got for 250.
the owner before that was mazda.

There are many vacuum lines and multiple vacuum port locations. It's hard to tell which one you're talking about just from the description. A picture will help a lot. It might not go anywhere...might just need a cap.

An open vacuum port explains your problem, though. The engine is getting more air than the air flow meter is indicates to the control system (ECU). Even before you figure out where it should go, you can cap it or close it off with a clamped piece of tubing to see if that let's the engine idle normally.

Make sure the pressure sensor is plugged in, and that the vacuum line connects to the intake manifold.

You can find all the information about the vacuum lines in the manuals.

The Factory Service Manuals for all years of RX-7 (and many other rotary cars) can be downloaded for free here: http://foxed.ca/foxed/index.php?page=rx7manual . They contain all common service information information and more, and are an essential tool for any sort of service work that needs to be performed on these cars.

Additionally, the Haynes service manual for the 1986 thru 1991 RX-7 (both turbo and NA) can be found at most local auto parts stores or purchased from any good bookstore (ISBN number 1 56392 007 7). It is only about $25 and is a great quick reference for things like this. Not only does it contain most of the information in the FSM condensed into an easy to read format, but it includes full wiring diagrams as well.

These manuals will answer 99% of service related questions for the car and if you intend to do your own repair work, you will need at least one of them. Preferably both, since the FSM is a free download. The Haynes is a good quick reference covering 99% of questions, while the FSMs show complete and detailed procedures.

Test the primary injectors. Injector failures are VERY common after the car has been sitting.

thanks for replys
but can some give me a list of what it can be from most likely to least likely
and i post pic of the engines tmrw if that will

i bought all four injectors but i think the leak is coming from intake manifold but i cant hear it