3.5 compression

[buggeroffroad]

hi all can anybody tell me what the compression of a 3.5 injected motor should be! cheers

[dsdlr]

All Aussie 3.5 EFI engines are 8.35:1 compression and should test at between 110psi - 130psi compression for a healthy motor. Anything under 100psi you'll start having trouble getting enough vacuum to open the airflow meter flap and start fuelling.

[buggeroffroad]

thanks for that its got between 90 and 60 so might be time for another motor.

[BigJon]

thanks for that its got between 90 and 60 so might be time for another motor.

Little bit tired! A worn cam could also contribute to low compression values.

I have no idea what mine is, but I am due for a rebuild anyway (bearing issues).

[buggeroffroad]

yeah well a fresher second hand motor is coming for it over the weekend just got to pick it up and by-by to the troublesome efi it has a stuffed ecu too i am suspecting as 2 injectors have stopped working for some reason after i put all new ignition components so i am going carbs at least ya can fix them. :D