Injection/Ignition Trigger

Hello all,

A complete novice question here.

I'm still trying to cure the rough idling on my 1972 Triumph TR6 and so already thinking of upgrading the EFI system I'm struggling with.

I understand that a crank position sensor will control the ignition timing and that a cam sensor will control the injection timing. In my case I only have a sensor built into a modified distributor to control both ignition & injection.

I'm now considering fitting a trigger wheel and crank position sensor to control the ignition. What about distributorless ignition? Some of the Triumph TR parts suppliers can supply a "blank" for the distributor once it's removed, but this is the only location on these old engines where camshaft position can be measured.

So how is the fuel injection timing controlled, can this be by the crankshaft trigger wheel also?

There is sequential injection and ignition (requires both cam and crank signals), and batch injection with wasted spark ignition (requires only a crank signal). Many early EFI systems were the latter, so potentially better than a carburetor, but not as smooth as modern fully sequential fuel & spark. The ECU works out when to inject the fuel and trigger the spark for each of these setups, it's just a matter of how many injectors / coils are controlled for engine cycle (2 revolutions).

You could build a trigger setup (both crank and cam) that was driven entirely by the distributor, but a better solution would be to use a crank trigger with a large diameter trigger wheel (could be mounted on the flywheel), and a simple one tooth cam signal driven from the distributor shaft. I would configure an individual coil-on-plug or coil near plug ignition setup driven by a modern ECU.