Tachymetric Relay

[autograsser 0]

do i really need the tachy relay??

 

im building my track car and was just gonna wire the fuel pump in off a switch??? is this possible, i noticed that terminal 9 is from the tachy relay is this connection needed and if soooo would i be able to give it a feed from the starter button ( as my autodata cd says it just gets volts on cranking)

 

im basically try to make the system as simple as possible and get rid of ANY wiring thats not needed especially if its got potential to fail track side

[welshpug 1,623]

yes lol!

 

you could wire up a relay and switch if you really wanted to, but the tachymetric relay is like a failsafe, when the engine stops so does the fuel pump.

 

 

one Idea that I haven't looked into is the double relay used on later systems, these tend to be far more reliable, might be able to utilise it in some way?

[autograsser 0]

yes lol!

 

you could wire up a relay and switch if you really wanted to, but the tachymetric relay is like a failsafe, when the engine stops so does the fuel pump.

 

 

one Idea that I haven't looked into is the double relay used on later systems, these tend to be far more reliable, might be able to utilise it in some way?

 

 

hmmn

 

well its deffo coming out and going off a switch so do i need to feed a voltage to pin 9 under cranking or doesnt it matter

[welshpug 1,623]

I would not put it on a switch, if you crash it the fuel pump will keep on going, NOT GOOD!

[jimbean 0]

yeah just remove it it is a anoying fault causing relay

 

all it does is turn the fuel pump ecu and coil on

 

i have done a few rally cars and oval 205s and have put the lives on switches

 

if you are worried about welshpugs comment bout fuel pump staying on after a crash fit a crash switch off a 306 or 106

 

or just a kill switch

[Craigo 0]

my relay died the day before my last track day, so thinking that it just controlled the fuel pump, wired a switch to the fuel pump, and also a in line inertia switch for safety.

 

tried starting the car, and no joy, turns out the relay also controls the injectors, it would not send any fuel without this relay,

 

so in the end we soldered up the f***ed relay, and it worked! a new one is on now though!

 

so you can get rid of the relay, but you will have to do some work on the injectors as well as the fuel pump!