Shimming Fuel Distributor??????
03-28-2002, 07:55 PM
#1
Track Day
Thread Starter
Join Date: Dec 2001
Location: New Jersey
Posts: 15
Likes: 0
Received 0 Likes
on
0 Posts
Shimming Fuel Distributor??????
I have read several times on this board about shimming the fuel distributor to increase fuel supply to injectors. How is this done and where do you put the shims? thanks for any help.
03-28-2002, 08:29 PM
#2
RL Technical Advisor
Hi:
This isn't something to be done *****-nilly.
You need either a good quality CIS pressure guage to set the control pressure accurately or a chassis dyno equipped with a Horiba Fuel-Air analyzer; preferably all of these.
Then, you need a good selection of the little brass or stainless steel shims from Bosch to make any adjustments. On the side of the FD is a bolt that retains the control pressure relief valve. One adds or subtracts shims of varying thickness to make control pressure corrections.
Bosch & Porsche publish a range of control pressures that you can shim, for adjusting mixture through the RPM range. When you are done, you will need to reset idle mixture.
Please do not attempt this without the proper tools and equipment for this. Its easy to ruin the drivability or raise the pressure that makes it too lean.
This isn't something to be done *****-nilly.
You need either a good quality CIS pressure guage to set the control pressure accurately or a chassis dyno equipped with a Horiba Fuel-Air analyzer; preferably all of these.
Then, you need a good selection of the little brass or stainless steel shims from Bosch to make any adjustments. On the side of the FD is a bolt that retains the control pressure relief valve. One adds or subtracts shims of varying thickness to make control pressure corrections.
Bosch & Porsche publish a range of control pressures that you can shim, for adjusting mixture through the RPM range. When you are done, you will need to reset idle mixture.
Please do not attempt this without the proper tools and equipment for this. Its easy to ruin the drivability or raise the pressure that makes it too lean.
