I have an 86 rx7 that has been sitting for 10 years....i just replaced the fuel pump and it starts up now but it wont stay on...not sure if its my battery, my alternator or my MAF...Any suggestions?

 

How long does it run?

 

like 5 seconds....the baterry was kinda low but im not sure if that was the problem

 

Has the fuel filter been replaced? Try jumpering the fuel check connector. The connector is Yellow hidden inside a Black rubber boot located by the passenger strut tower. It is part of the Emission harness that feeds the Pressure Sensor and the plug has two wires, one Black and one Brown.

 

If the car has been sitting for 10 years, you will need to rebuild the entire fuel system:

http://www.aaroncake.net/rx-7/unstore.htm

Also make sure the AFM flapper moves freely, and test the fuel pump cut switch.

 

the car stays on but it wont idle. if u keep reving the engine it stays on but it just wont idle. any suggestions?

 

Does the idle bounce? Does it not bounce but stays at a high rpm which is steady? Be specific.

 

the rpms shoot up as soon it turns on but soon as ot reaches its peak it shuts it doesnt idle unless i keep my foot on the gas. it just doesnt idle and i already tried to adjust the idle screw.

 

If you have to keep the foot on the pedal to enable the car to run you likely have a vacuum leak or the AFM flapper is problematic.

 

Check the black plastic air intake pipe going to the AFM for cracks/holes. I read similar posts where the intake piping being cracked was the problem or the air filter was clogged.

 

I agree probably a vacuum leak/bad fuel system/ fouled plugs. You might want to empty out the gas tank as it has degraded over the years and put fresh gas in the system. It could also be the alternator if it starts but won't stay on..

 

You are chasing your tail until you flush the entire fuel system, replace the pump and filters, and have the injectors professionally cleaned.