87 na
no cats,borla exhaust with silencer


the other week my car was running perfect just got the new engine running and everything, all of a sudden i start it up and its shaking and hard to gain acceleration. when i push the gas pedal down on neutral the rpms get tougher and tougher to raise more than 5k, it usually has no problem getting to 9k. it makes like a cherry bomb exhaust sound (farting) when stepping on the gas. i rose the car and cant find any exhaust leaks but i cant be sure without actually using a scan tool or evap machine which i dont have.

 

When you say "new engine" , do you mean 1) mazda reman, 2)rebuilt or 3)used out of a questionable car but new to you?

That will help with what direction your help will go.

Did you check compression?

Post your numbers after you run the check.

Check timing and plugs +wires.

Could be as simple as fuel filter or clogged injectors too.

john ny

 

rebuilt engine and you know it might be the fuel filter it hasnt been changed yet

 

check the engine and injector...

 

ok so its not the fuel filter i just changed that today. also i think i should add that flames are coming out the exhaust and they are not small at all.

 

lol

 

Sorta eliminates the possibility of a lean misfire due to a vacuum leak...

1. compression?
2. fuel pressure? (high, i.e. failed regulator, or clogged return line?)
3. check for trouble codes
4. TPS
5. AFM
6. boost sensor
7. air pressure sensor
8. water thermo sensor
9. intake air temp sensor