[Siquemacuhz]

Getting ready to change cap and rotor on my 2000 4.3 and figured I should do compression test while I have all the plugs and wires off. just wondering how necessary is it to disconnect the fuel pump and ignition module? can I get away with not doing it? If not, do I just take out the fuse for fuel pump relay and the ignition module?

 

[songshun]

hope you shut it down to make sure the safe.

 

[oldeerslayer]

It's so easy to pull the fuse on a 2000, why not just to be on the safe side. The ECM1 fuse right above the fuel pump relay feeds both the ignition module and the injectors.
Be sure to open the throttle some when doing it. Air has to be able to be sucked into the cylinders, to be compressed to get accurate readings.

 

[Siquemacuhz]

Appreciate y’all 👍🏼 Got it done about a week ago pulled fuel pump fuse and grounded coil wire. Bricked the throttles day let it turn over about 5 times each cylinder. All cylinders read between 175 and 180 psi 👍🏼👍🏼👍🏼