H4Inf

First of all this is in regard to a 1988 Turbo II.

There's about an hour worth of daylight left and I need to finish this job today. What I am trying to do is put in a bypass to keep running the fuel pump after ignition has been turned off.

Theres a control relay and then a seperate fuel pump relay and resistor. Just wondering why is there a resistor in that relay?

In order for me to get this setup to work I will ned to bypass both of these relays and cut in directly between the fuel pump and the FP control+resistor relay. I'm just wondering why there is a resistor there and would it be ok to bypass it and hook turbo timer direct 12V to the line going straight into the Fuel Pump.

There is also an alarm system installed which is causing all the hassle - I've had to install a few relays so that the car is able to arm whilst still running - the alarm has to think that the car is off in order to arm.

So basically my question is - is it okay to put in a relay between the FP Resistor relay and the fuel pump, to supply 12 Volts direct to the FP?

Cheers! Thanks in advance,

Paul.

RETed

Mazda designed it so it will not stress the fuel pump as much.
Under low load, the demands on fuel (delivery) is not high, so they use the resistor system to drop the voltage to the fuel pump.
By lowering the voltage to the fuel pump at low demand, the fuel pump lasts longer.


-Ted

NZConvertible

Why? The fuel pump control system is designed specifically to stop the fuel pump if the engine is not running for YOUR SAFETY.

H4Inf

Thanks Ted.

I am installing an alarm system/immobiliser and a turbo timer. The alarm system does not support turbo timers, so I am having to put relays between the alarm system and the car so it doesnt detect that it is running, and then also bypass relays for immobilised components - the fuel pump.

So - I switch key to off. Turbo timer takes over, Ignition relay allows car to run, but tells the alarm system that it's off. FuelPump Bypass relay runs the fuel pump, allowing the builtin immobiliser relay in the alarm system to cut off the fuel pump. The starter is also cut, hiowever there is no need to bypass that, the car runs without it.

It's an absolute mess, and I recommend to anyone wanting to both immobilise, alarm and turbo-time - BUY AN ALL IN ONE ALARM. This is chaos... spent maybe 4 full days troubleshooting this and it still doesnt work.

I have given up on getting it to work and have accepted that it's not going to happen. So basically turn ignition off, lock doors manually and walk off. After the car stops theres a 30 second delay before the immobiliser kicks in, and the alarm does not function at all in this manner - unless you hang arond until the turbo timer has finished running the car, and then press the arm button.

Next time I'll buy a viper alarm - builtin turbo timer. Simple

Has anyone ever noticed how hard it is wiring things under the dash? Very tight small space! Argh.

NZConvertible

You want the easiest and cheapest solution? Don't use a turbo timer. You have a water-cooled turbo so you do not need one. Just do what it says in the owners manual of pretty much every modern turbo car made and don't drive the car hard for the last mile or two.