lloydie wrote:When running a pump you need to split the diaphragm in the fuel tap and block the vac pipe both at the engine and on the tap .tony.mon wrote:Not far, as it turns out, not even off the drive this am.tony.mon wrote:
I rode it to work today, nice journey in but it went onto front cylinder only about five miles from home, and cut out the second cylinder two hundred yards from home, coasted onto the drive.....result.
A fuse blew powering the fuel pump, they apparently draw more than two amps.
Fixed that, let's see how far I get.....
Fuel tap problem, it's not compatible with a fuel pump so I've had to bodge a temporary get me to Wales fix.
Running fine into work, let's see if it will keep going to Wales this evening.
The reason was that when turning ignition on before trying to start it (I have to, it takes the preheaters on the Lambda sensors a few seconds to warm up) the fuel pump tries to suck fuel from the tap.
It can't, because the engine isn't cranking, allowing the vacuum to open the tap.
So the seal and plunger (smaller of the two tap diaphragms) gets sucked into the tap and it gets locked there under the pump vacuum.
When the engine is cranked, there is such strong suction from the pump the vacuum can't pull the tap's piston back across.
The piston and diaphragms are only clipped together by a little "rubber" button, and because the vac form the engine and the vac created by the fuel pump are pulling in opposite directions the sections can separate.
I found another way, remove the larger (vacuum) diaphragm, fit the spring between the tap and the internal end of the plunger and the tap body.
That way the fuel diaphragm cannot fully enter the tap body, and the vac from the pump cannot create a vacuum. The spring pushes to shuttle across holding the tap open.
Works fine, and if the smaller diaphragm splits fuel will still flow out of the overflow, showing me what's wrong.