i have an 87 n/a it needs a fuel injector (i think). the batery wont stay charged.it doesnt stay runnin(as soon as i let off the gas it dies off). below 3500 rpm it runs extremly bad(above though it runs fine).should i try to rebuild or buy used and/or what other options do i have.

 

and why is my envalope(i cant spell)dark grey while all the others is red?

 

First see what shape it's in.
Do a compression test.
Check for intake air leaks.
Clean and/or replace grounds.

You might be in better condition than you feared.

 

first you should diagnose the problem before thinking its the engine thats bad, check your charging system first (ie alternator, battery, grounds) then do a compression test....

 

if u buy a used motor u would still have to rebuild it anyways.... like my 88 7 TII... it had a used j spec motor... no telling what those japs did to it... it shoulda been rebuilt before it was put in the car, but the previous owner just threw it in, and it only lasted 400 miles with his setup...