Hey guys, I just bought an 87 rx7 with 131k, it is idling at 1500rpm and its backfiring. What's the problem and how do i fix it?

 

vac leak

cheak all vac lines

 

will do

 

Like he said. The most common problem with our cars that affects idle is vacuum leaks. Instead of checking all the lines, I would just go ahead and get ALL new lines. After that many miles, it's needed. Get some nice silicone (except for gas lines) vacuum lines.

Since replacing all the vacuum lines will require taking off the UIM, go ahead and get a new gasket for the UIM/LIM connection. Gaskets are a great place to spring a hard to detect vacuum leak.

After doing all the vacuum related fixes, adjust your TPS.


Edit: Btw, that new gasket is like $4 from http://www.mazdatrix.com .