testing throttle bodies

[benzboy]

does anyone have a way to test throttle bodies. im not sure if mine need rebuilt. I would like to test them, before I would have to send them out. btw the car is a 73 911e mfi. thanks

[jpnovak]

A few simple tests when they are on the car.

Remove the throttle plate connecting rods (X4). Grab the side linkage of the throttle plate and wiggle. There should be no play in any direction except rotation. Any play and they will need to be rebushed.

When off the car, look into the intake tract. If you see any contact of the throttle plate to the sidewall then they are really worn and will likely need to be machined and new throttle plates fit to eliminate the grooves and cut marks.

[tharbert]

All the above plus... You can hook up a shopvac to one side and use a synchrometer to measure air leaks.

Rebuilding these puppies is $pendy.

[boxster03]

if the mfi is dialed in and you are always idling high likely you have wear and will need attention to the throttle bodies

[benzboy]

yes I do know they are very expensive too rebuild. I cant get my car to run right. it has to do with the mfi pump. its running too rich and cant seem to get that right. its a fresh top end rebuild on the car too. I thought possibly doing the throttle bodies also.

[kugelfischer]

I'm assuming that you have followed the CMA procedures to the letter?
Pelican Technical Article: Mechanical Fuel Injection Information MFI