3.2 Compression test - what to disable fuel/spark?

[r-mm]

Quick one - how to disable fuel/spark to do a compression test on a 3.2?
Thanks

[Joe Bob]

Pull the coil wires to the distributors.

[r-mm]

And just let the gas flow?

[911pcars]

Do you know how to connect a remote starter switch (to the solenoid)? If so, disconnect the DME relay under the seat. That should disable the fuel pump and ignition system.

Actually, I'm not sure doing the above will disable the cranking circuit. If not, just pull the relay and proceed with your compression tests.

Sherwood

[db_cooper]

Remove the holder/relay and pull the DME relay under the drivers seat. No fuel and spark. Good time to replace it with a new one from our host and put the old one in the glove-box as an emergency spare.

[Sboxin]

Please refer to Pelican's Tech article

Pelican Technical Article: Time to Rebuild? - Part II

Remove DME relay and fuel pump relay
The article also discusses the removal of the spark plugs cold and hot conditions

Regards,

[James Brown]

use the remote starter switch, pull the coil wire, put in neutral, keep key in pocket, pull all plugs.
make a copy of above and laminate it to the remote starter cable so the next time you know

[Eagledriver]

Don't forget to open the throttle while doing the test. I just put the center distributor wire next to a ground so it can spark there harmlessly. I let the fuel flow, (never noticed it).

-Andy

[E Sully]

Just pull the dme relay, don't disconnect anything else. Keep the gas pedal to the floor.

[r-mm]

Thanks everyone. Couldn't find these procedures in Bently. Pelican link is great.

[db_cooper]

Just be careful with random sparks from the coil/spark plugs with the fuel injectors energized and the fuel pump running, if you go that route. That's why removing the DME relay is suggested.

Saw a film of a fuel injected VW bus being tested using the easy short cut method..pull the coil wire and while doing a compression test..the fuel vapor from the spark plug hole(s) ignited....burning down a garage.

[john walker's workshop]

on the rear shock crossmember, just to the right of the upper left shock mount is the DME plug to the injectors. unplug it. easy and accessable.