Idiot! Took Out My Tachymetric Relay

[DrSarty 90 1 Cars]

Did quite a good job seperating engine loom from dash loom when stripping 1.6GTi engine & ECU from Pug before dropping in BX16v lump, complete with its loom & brain.

 

It's all plugged in and is running (if misfiring on 2 & 4 SEE OTHER POST - & is still in the workshop), but to do this I had to rig up a switched live to the fuel pump after learning that I shouldn't have lifted the tachymetric relay out.

 

I plan to install a 'hidden' switch + relay in this circuit anyway, BUT, I've since figured that the YELLOW SINGLE WIRE exiting the ECU connection, which on the donor BX16v disappeared towards the rear of the Citroen was/is a fuel pump wire anyway.

 

I'm aware of the hazard of having a fuel pump NOT cut-out in the event of an accident, so I was wondering, does this yellow wire, plus the gubbins inside the 16v ECU carry out the job of the tachy relay?? In other words, is the original 205 tachy relay not required, in favour of simply connecting the aforementioned yellow ECU wire to the fuel pump???

 

All of my posts have been answered most promptly and professionally - is this still my lucky day??

 

Regards dudes

 

Dr S

[jackherer 543]

the tachymetric relay isn't used with an MI16 (which is good as they are pretty unreliable).

 

the yellow wire you've identified is actually the output from a standard fuel pump relay on the bx loom so connect that to wire 76 on the 205 and you have a factory fuel relay doing its thing based on input from the ECU (so if the engine stops turning over fuel stops pumping).

[Ryan 99]

It does yes. If the engine stops running for any reason then the ECU will cut the power to the fuel pump.

 

I connected the yellow ECU wire to the thick white wire that used to go to the tachymetric relay (wire 76 iirc), that way the fuel pump still goes through the fusebox, instead of direct to the pump as I believe it's wired in the BX.

 

EDIT: Damn you, beat me to it!.

Edited September 5, 2006 by Ryan

[DrSarty 90 1 Cars]

Thankyou thankyou,

 

My mind is at rest and I can just connect the yellow wire from the ECU (I now know from one of the loom relays) to the thick white no76 from brown plug near column, which used to go to my tachy relay.

 

Again, most reassuring and proves I have a brain after all, as you ALL clearly have too! Except the HONK HONK fella in the vid posted earlier

 

Cheers one and all

 

Dr S

 

P.S. Means I have a tachy relay for £3 plus P&P if anyone wants it.

[jimbean 0]

the mi does not have a tach relay but does have a fuelpump relay which is close to the ecu on the bx and in the fuse / relay box under bonnet on 405 the ecu turns the fuel pump on via this relay and is the equivelant of the tachy