EFI Control Relay

[mightymouse]

If anyone is converting to EFI from a carb (Steve) its important
that the fuel pump is controlled either by the EFI system itself
OR by a seperate specialised "control relay"

One solution is a Bosch "Tachometric Relay".

The most common use ( and therefore wrecker available ) is off a
VK Commodore BOSCH P/N 0 280 230 005.

This is a multiple output relay that also has "cranking" and
"tacho" inputs. Fuel pump will be on whilst engine is cranking
and running but will cut out if neither signal is supplied after
around a second or two.

The connections are numbered on the relay - using standard BOSCH ID's

Terminals

30 + from Batt
31 -
15 + from ignition
1 Ignition Coil ( RPM Pulses )
50 Start Solenoid
57 Switched + for Injectors etc ( optional but good idea )
57B Switched + for fuel pump

Note : EFI fuel pump control is required by law. The consequences
of high pressure pumps left running in an accident are very severe.

Switching the + to the injectors may seem like overkill - however the
ECU grounds the injectors to operate and therefore a short etc can
leave the injectors stuck on.
An ECU failure can also produce the same results.

[gwagensteve]

Thanks Mightymouse -

I will be sorting that out along with my weeping fuel fitting, overfuelling and VSS signal as priorities. I do understand the safety issues.

considering the speed the conversion was done in, all up, I was pretty happy.

It actually held 78km/h over cottons pinch between Molesworth and Yea, laden and with 2 people on board ( I drove Noel home) which is about 15 km/h faster than the Gwagen could manage with the same load!

Steve.