Swapping fuel pump

Ian Anderson · Post by **Ian Anderson** » Sat Aug 11, 2012 4:58 pm

In the GT40 3.9 hotwire I was running a Bosch pump from the swirl pot.

I got some crud in the feed to the swirl which caused the hp pump to suck air

After that the pump would run but after a few minutes would scream.

I decided to switch fuel pumps today.

Well the Bosch had 2 screw on terminals (wire had a ring end) od different sizes. Small for positive and large to earth

New pump has 2 spade connections one standard 6 mm and the other about 8 mm

There is no marking on the pump to show positive or negative

Does anyone know on a Lucas Bosch pump with spade terminals is the large or small one the positive feed?

Cheers
Ian

Ian Anderson · Post by **Ian Anderson** » Sat Aug 11, 2012 5:51 pm

Pump looks like this (but is new!) it has no electrical markings

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... 0746307311
Ian

DEVONMAN · Post by **DEVONMAN** » Sat Aug 11, 2012 6:31 pm

Hi,
My Bosch with spade terminals has the large one as positive.
It's marked on the brown plastic moulding at 45 degree to the pipe stub.

Cheers Denis

Ian Anderson · Post by **Ian Anderson** » Sat Aug 11, 2012 7:37 pm

Cheers Denis

I will try that tomorrow

Ian

DaveEFI · Post by **DaveEFI** » Sat Aug 11, 2012 9:51 pm

If they're swapped, it will just run in reverse. But don't do this for long.

Ian Anderson · Post by **Ian Anderson** » Sun Aug 12, 2012 7:35 pm

Connected it up today and she fired straight up.

Went for a short run and appeared to have more power. Perhaps the old one had been fading more than I thought!

Thanks again

Ian