tii fuel delivery checks:
If you tii was running like a champ and then suddenly begins to run sluggish, surge, sputter or seems down on power, a possible culprit can be in the fuel delivery system.

1. Disconnect the battery and make sure you are working in a well ventilated area as you are working on the fuel system. Use caution as there will be some gas spillage in replacing the filter and/or cleaning screens. I prefer to work on a cold engine – do not work on the fuel system with a hot engine. I’ve whittled some dowels down so I can plug the fuel hose ends to help contain the amount of fuel spilled
2. Check the main fuel filter by the radiator support. Remove the filer and replace it if you can’t remember when you last changed it. In an emergency, tapping on the filter may help you get home or to a service location, however, there is risk that the junk causing the blockage will end up in you KF. Bad juju. Use only the tii specific filter (either Mann or Purolator) and do not use a cheap plastic/paper filter as the high pressure will destroy the paper element. Order 2 from your favorite vendor. Keep one in your car as part of your tool kit and replace annually.



3. Check in in-line filter for the KF. Follow the line from the filter to the KF. Loose the banjo bolt and clean the screen. Be aware the screen is NLA. Replace the crush washers.



4. Check the in-tank fuel screen for junk and while you’re at it, check the tank itself for sludge/crud or other accumulation after 30+ years. If there is any of above, carefully pump out or siphon the tank into an approved gasoline container and dispose of properly. Re-fill with fresh gas.



5. Check the in-line filter by the fuel pump under the rear axle. You will probably need to get the rear end elevated. Do not wear a favorite shirt but do wear gloves and eye protection and have a stopper ready as gas will come out of the line from the tank. If you jack up the car be sure to support the vehicle with jack stands at the appropriate points and block the front wheels. This screen is also NLA.


6. While you’re at it, order genuine BMW fuel hoses and replace them if you haven’t in a while. 2 meters should be enough to replace all the hoses. Do not buy cheap fuel hoses as the high pressure in the system will blow the hoses!! I use the rubber ones from BMW, some may opt to go the cloth wrapped hoses as they are period correct

If these checks don’t fix the problem, your fuel pump could be at fault.
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Colin K.
Malaga '72 tii