E30 Zone

I need to replace the fuel return hose that goes from the regulator on the end of the fuel rail back down to under the brake master cylinder/fuel filter. Car's an '87 325i. Can anyone tell me the size I need - inner diameter and approx length - so I don't have to take it off first... Also, which fuse/relay do I need to remove to depressurise the fuel system?

As well as that, I'm looking to bypass the throttle heater where the coolant circuit joins the throttle. I've found already that the current hose won't stretch from the thermostat to wherever it goes at the back of the engine. What diameter and length do I need for this coolant hose? Or is it easier to get a male male connector and just join the 2 current ones together under the inlet manifold?

All help much appreciated
Finn

Bump!
I popped into Halfrauds this morning and they seem to have a multitude of fuel hose sizes, but all measured by the internal diameter. Any idea which I need before I have to go dismantling in Halfords carpark?!

In case anyone else is wondering about this, the fuel pipe was 7.6mm diameter, 1m length. Got a replacement from Halfords.

To bypass the throttle heater I decided to join the two pipes together so that I can put them back on later if I choose. I used a plumbing connector from B&Q to do the job. Something like this with the ends taken off:

This has worked a treat. Just slid the pipes over the threaded parts of the brass connector and tightened the jubilee clips up over it. No leaks, and the throttle stays nice and cool all the time now. No idea what kind of improvement in intake air temp I'm getting but it's got to be a little better.