SPi to Carb Conversion

SPi to Carb Conversion

Author
Discussion

DavieW

Original Poster:

749 posts

108 months

Sunday 17th October 2021
quotequote all
Has anyone got a step by step guide to convert an SPi to carb/points? I'm fed up with the numerous intermittent issues with the electronic sh*t on the car.

CarsOrBikes

1,135 posts

184 months

Sunday 24th October 2021
quotequote all
no need for point setup, keep ECU, keep fuel tank and pump, filter etc, keep fuel return, keep purge valve and pipes, delete air box, delete PCV pipe behind rocker cover, delete injector and manifold, delete lambda sensor, delete all vacuum/fuel traps, delete air temp sensor, install water cooled carb manifold with brake servo port and vacuum port, tap into fuel supply/return loop and add pressure regulator to reduce pressure not increase, connect PCV hose/s to carb breather/s and tee purge supply to same, or vent engine breathers to atmosphere via filters or better still pipe to to added exhaust port (post cat ideally if applicable) and just run purge to carb breather instead, rotate existing servo hard pipe unions to facilitate connection to manifold location, remove control cable panel and run choke cable through existing bulkhead hole, swap throttle cable to carb type, move coolant temp sensor to front of head, note not taper fit but seated type for engineering purposes, remove harness from car, un-tape and trace no longer required connectors and related wires to ECU connector and note positions accurately for reinstatement, 'pull' wires from ECU connector (pop out), for stepper connector, air temp connector, injector connector etc. Re-route coolant temp connector wires along alternator wire path and re-tape to permit correct location at front of head, reinstate loom and connect, add blank plug to lambda port, connect and set throttle and choke cables, add air cleaner version of choice, add vacuum hose from original air box to new manifold location (from ECU), start and tune carb etc. Set fuel pressure ~4-4.5psi, check leaks. Tune on rollers for needle options/spec.

just my 2p ;O)

been running this since 2005 to ~97hp on twin 1.5" SU's