[Manx]

Hi all,

I'm looking at the options for aftermarket ECUs for a 2.0 twinspark from a 75 - being transplanted into a 105 running carbs. Can anyone give a quick list of what sensors are going to be left on the bare motor once the fuel injection setup has been removed.

I'm thinking the following - can someone suggest any others - or even better point me to a diagram.

- The AFM will be gone.
- Coolant temp.
- Oil pressure - but where is it located?
- Reluctor sensor on crank
- Oil level (is the one under the dizzy?)

Is there any timing sensor on the cam I could use for a sync - or has anyone made one? Perhaps using the upper dizzy?

Many thanks.

 

[69alfa]

The equipment would include:

Crank shaft sensor with a 60-2 toothed wheel
Coolant temp sensor

Over heat switch
low oil level switch
low oil pressure switch

oil pressure sender (intake side half way down near the back)

VVT solenoid


IF you remove the intake plenum you will be missing:
MAF or Mass Air Flow sensor
Air temp sensor
idle air valve

 

[Manx]

Could the MAF and air temp sensor be built into an air filter housing on a carbs set-up? Assuming I borrowed the sensors from the 75 set-up.

 

[69alfa]

I am not to clear on what you are trying to do .

If you want the computer to just do ignition I don`t think you will need MAF and air temp.

Alfaholics has a setup for carbs and electronic ignition you would need a throttle position sensor for that to work.

Full 3 Dimensional Ignition Map for Twin Spark | Classic Alfa Romeo spare parts and accessories

 

[Manx]

Yes of course the Throttle position sensor, forgot about that one.

You may be right about not needing the MAF or air temp - but I'm just not sure what variables the ECU uses in it's algorithm to adjust ignition timing.

I'm most probably going to use this system:
G4 Storm - Comprehensive Engine Management — Link Engine Management Systems - plug-in & wire-in aftermarket ECU's
which has an inbuilt MAP sensor anyway so that is not a problem.

This system also has an output for controlling the VVT, but that may need more research, any thoughts on that? I don't thoroughly understand the VVT yet - there's not really a lot on the BB that I've found.

I also want to keep my options open if I do want to revert to an injected system one day.

Any thoughts on a cam sync? I think I need one if I want to run a direct spark set-up. My thoughts were an optical sensor in place of the distributor at the cam.

 

[69alfa]

Looks like a nice system.

You only need a cam sensor if you are going sequential injection or coil on plug ignition.

That system has 4 ignition outputs. If it supports Twin Spark you can use 4 GM coil packs . The coil packs are waste spark so you make pairs of 1-4 and 2-3
When you want 1 to fire at TDC it also fires 4 on exhaust .

So it would go:

Coil 1 front plug 1 and 4
Coil 2 front plug 2 and 3
Coil 3 rear plug 1 and 4
Coil 4 rear plug 2 and 3