I would appreciate any information/advice on a problem re starting on my 2C-T engined Masterace. It has always started immediatley, from cold and hot, but,
for the past couple of days, the first, or cold start, has been very difficult and, almost to the battery flattening stage. I have checked the glo-plug feed and each is getting 12 volts at switch on. Is the "idle up" device, ie, the vacuum unit fitted alongside the fuel pump and linked to the throttle lever, utilised in any way (automatically)on a cold start, ie, pulling in when there is some vacuum, irrespective of the operation of the idle up or aircon switches?
I can get the engine started, eventually, by a precise lifting of the throttle but, should this be done (on a cold start)by the idle up unit? As it happens, my idle up unit does not work when the switch is depressed, even though the heater fan is running, and I wonder if this has something to do with the very difficult, initial, cold start. The idle up diaphragm seems OK as it will pull in the lever with a suck on the hose but, I have yet to check the two vacuum valves and connections. Once the engine is warm, starting is no problem. If anyone could comment it would be much appreciated.

- (#9171) John Davis, 16 Jun 03 10:58

I'd look for an air leak round the fuel filter if I wher you, John. In this weather it'll not really need the glowplugs...

The cold start device utilises the same linkage as the "idle-up", but is actuated thermally. When cold, the switch will have no additional effect.

- (#9172) david miller, 16 Jun 03 12:29

Thanks David. I must say, I had discounted fuel because of the fairly large cloud of smoke when it does eventually get going. However, of course, even a tiny air leak on the suction side, presumably, between pump and filter could be the answer. That will be tomorrow's check

- (#9173) John Davis, 16 Jun 03 13:38

David. Spot on again, many thanks. After an elimination process, I found that the "head" of fuel, under a vacuum, in the suction line from the tank to the fuel filter, was failing overnight or, after a prolonged stop. No problem with the pipework but, it would appear that the priming pump, which has to be airtight, has failed and I think that the fault is in the "rolled" edge, which keeps both halves of the pump together. I have by-passed the filter and priming pump and this has cured the problem. However, this priming pump is a sealed unit and I am unable to inspect/repair the valves or diaphragm. Does anyone, by any chance, have a spare fuel filter mounting bracket/priming pump which they wish to sell?

- (#9174) John Davis, 17 Jun 03 9:26