"I know these bits are good. The idle is all over the place, the injectors probably need replacing and I think most of the vacuum lines leak, It fires on all four, but eventually chokes itself up with too much fuel".....
>>>Vac leaks, if present would result in LEAN condition. Your rebuilt FD may be set way too RICH??? I think there is a recommended starting point for this, but the details escape me right now.<<<

Here is my plan to tune up the motor... >>>I deleted the steps I have no comments on<<<
B21E Tune Up Sequence

>>>I'd check the Aux Air Device and it's hose connections before trying to run it much. Is it Open when cold and Closed when warm/hot? No "False Air" sneaking in thru loose/cracked hoses?<<<

6. Once nothing can leak air, run it to operating temp, then take the valve cover off to re-torque the head bolts.
>>>Relax torque first? In what sequence? Then do the same 2-stage torque sequence? Just curious.

9. Now that we know the idle is set up right as far as air goes, let’s get to work on the fuel flow. >>>Engine (and CPR/WUR) should be Cold for fuel flow test -- to eliminate warm CPR influence, per Bentley Bosch FI book (BBFI). Wait for block to cool (or do flow test before running engine. Also unplug CPR heater to be sure.

Unplug the return line to the tank and prime(?) the fuel pump to run continuously. Once running it should circulate at least half a litre of fuel every minute.....>>>My old Bosch book and BBFI book say 750cc in 30 seconds. PLUS BBFI gives a test not mentioned elsewhere: "Control Pressure Throughflow", to test the internal FD for clogs and /or too little restriction where required. Connect a line to the CPR outlet on top of the FD. Run the pumps for 60 seconds. Output should be 160 to 240 cc. Too much or too little = bad FD. They say CPRs get needledly replaced if this flow isn't tested.

10. Confirm ohmic resistance on control pressure regulator is correct. I’ve given up on actually figuring out what the various pressures should be. >>> The CPR heater resistance only affects how quickly the Control Pressure rises from "cold running" to "warm running". In fact it should be unplugged for now. Regarding "various pressures", if you mean System, Cold and Warm Control, you will just be guessing at symptoms and fixes if you can't measure these pressures against the vehicle specs.

If the CPR appears to be OK electrically then it should be working well enough to tune around. If we are getting half a litre back with the ignition on run, then we can assume it works. >>> The CPR shouldn't be affecting fuel pump delivery, but should be unplugged anyway, as mentioned above.

11. Pull the rubber hat off the top of the airflow sensor. Check it’s positioning is Ok using three strips of typing paper and a magnet. Realign as necessary.(ugh looks fiddly, hope I don't have to) >>>This seems out of place (should be before running till warm to retorque, etc., since it needs to be right to run)

12. Next thing to do is check the flow from the injectors. When the airflow plate is closed, the injectors may deliver a trickle (>>> Not really, with no air flow or fingers lifting the plate.<<< but they should not be spraying. Put a Magnet on the bolt and raise it up and down. The injectors should all be delivering the same amount of fuel at each position >>> Are you planning to measure, with separate containers? and it should be an even spray. Replace the injectors if needed. Test the new ones.(>>>I think this level of detail could perhaps wait till later??? What if they're unequal? Is it injector or FD delivery? Maybe you should actually test for equal FD delivery first, with injectors removed, since it's also an "unknown".)<<< You know they should be getting even pressure from the distributor: you just had the thing rebuilt.


17, 18, 19, I like Rhys's method better, setting up at 10 degrees BTDC.

--
Bruce Young,
940-NA (current)
'80 GLE V8 (Now gone)
'83 Turbo 245
'73 142 (98K)
'71 144 (track modified--and going to be crushed unless...)
New 144 from '67 to '78
Used '62 122 from '63 to '67