Do you power the SU pump from the start position of the ignition switch, or a separate switch ?
Thanks
John
Do you power the SU pump from the start position of the ignition switch, or a separate switch ?
Thanks
John
You definitely want the pump in the ignition circuit. If you have a crash you (or a responder) wants to be able to isolate the pump with the key, not having it merrily pumping away on its own circuit.
I have put a separate switch in series with this though as a theft deterrent. It still gets its power from the ignition key though.
Thanks Chris, yeah that makes sense about accident scenario, the question is though with an electric pump in parallel with the mechanical one to overcome the starting issue, would it be sufficient to have the electric pump running while starter motor is turning over ?
Thanks
John
If you go to supercheap or autobarn you should be able to buy a fuel cutoff switch. It makes it safe to have an electric pump. They will prime for three seconds or so when you first turn the key and then they will only run when the engine is running. From memory they take a signal from the coil and if the engine stops they cut power to the pump. I would not run an electric pump any other way but I have swapped the manual pump to electric on one of my series and then ended up fuel injecting it because I got sick of carbies.
Good idea Tim, but i can't seem to find any on the Supercheap or Autobarn wesbites :-( I don't suppose you have a link to one please ?
Thanks
John
Sorry it's taken so long, I have been away from the computer.
They are called a tachymetric relay apparently and on eBay there are a large number of them from Peugots but the complete relay get a little expensive. There are also LPG safety switches which you can wire up to your fuel pump relay. These do exactly what you want, prime when the ignition is on and cutout when the engine stops running.
Hope that helps, I can't find the original one I had to get a maker or part number.
Cheers,
Tim.
Here is a link to one of the LPG safety switches, more expensive than I though they were, but this is exactly what I had for the electric pump and the 2.25 with a Zenith carbie.
https://www.ebay.com.au/i/1529531814...EaAndDEALw_wcB
My Thoughts also, Henry.
Fuel injected Series. Mmmm
whitehillbilly
I did post a build thread about it ages ago, I will see if I can find it and link it. It has been running for at least 6 years without me touching it again until just recently when a head gasket went and once I fixed that the gearbox now needs some work. Haven't really got finished getting it going again as I have had other personal and work things to do. but -
It is on my Game and I put individual throttle bodies off a Honda CBR600RR and the coil on plugs from the same bike. All controlled by a Megasquirt2 that does both spark and fuel. Wasted spark ignition driven using a 36 pin wheel attached to the front of the crank. The original distributor is still sitting there to fill the hole. It goes as. well as you can expect a standard 2.25 to go, with standard gearbox it will sit on 100k all day, even tow a trailer at that on the flat and return much better economy than the Zenith ever did. I have used this off road quite a bit, even up a creek that was over the bonnet and it has never failed me. The carbie always had an angle somewhere that it didn't like and would stumble or die, This is doing some fairly serious 4wding at the parks. FI has no problem.
Cheers,
TimJ.