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Shadow II no start

262 Views 12 Replies 8 Participants Last post by  claes.bjornefalt
I have a 1979 Shadow 2 that has been in storage for 8 years, always serviced and under 40000miles. today i have a crank no start issue. No fuel to the carbs. What could it be?’
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Suggestion: Pull every fuse on the fuse panel, clean contacts and install. Check for continuity with the fuel pump fuse. How do you know you have no fuel to the carbs? Fresh battery?
Will do, I've put a new battery on and can't hear the pumps going...but I'll check the fuses this evening
Tap the pump with a plastic hammer at the centre with the ignition on and the pump may start. Don't hit the plastic end caps on the pump.
I think the pump only runs when there is oilpressure, so when the lamp has lit.
Oh yeah Bert is right pump only runs on a Shadow II when there is oil pressure or when cranking the engine over. Pull the wires off the oil pressure sensors to test the pump with only the ignition turned on.
Oh yeah Bert is right pump only runs on a Shadow II when there is oil pressure or when cranking the engine over.
I don't think I have a one-off Shadow II, but I have to say I don't think this is correct.

It is common practice, and one I followed for years, to turn my key to the "Run" position and to listen for the SU pump to stop ticking prior to attempting to start. That way I new the carbs had been primed and were ready to go.

I could never get the car to start (reliably, anyway) after it had been sitting "long enough" for the fuel in the carbs to have evaporated. The instruction to "listen for the ticking to stop" has been repeated more times than I can count.

Of course, this only applies to cars with the dual SU fuel pump, and since the OP has a flag that suggests a home market car that's what I'm presuming. If it's the Pierburg pump, I still let the pump whir for a short time before I turn the key far enough to engage the starter.
TSD 4200 Chapter M ( 3-5) The coil of the fuel pump relay is earthed once oil pressure is established, thereby not allowing the petrol pumps to run when in the ON position or when the pressure is low.
Therefore, one must ground the lead at the pressure switch. The switch is normally open and when pressure ( 15psi) is proven the relay is grounded.
On my Shadow I, I could hear fuel pump when key on ACC, not Shadow II because connected to oil pressure for safety
What about ballast resistor too ?
Well, I can assure you that I can hear the SU pump on SRH33576 prior to attempting to start and the Pierburg pump on LRK37110 in the same circumstance.

And I cannot count the number of times, when discussing the two series cars, the statement has been made to listen to the ticking of the SU fuel pump before attempting to start.

The documentation is wrong if it says you can't do this prior to having started the car. I do know about the oil pressure cutout feature if the car stalls after the engine is started, but it is not in effect prior to that.
On my Silver Shadow 11 SRH37125 the twin SU fuel pumps only work when cranking or when driving if the wire is connected to the oil pressure switch. To get the fuel pumps to fill the carb float bowls prior to cranking I pull the wire from the oil pressure switch and then the fuel pumps operate once the ignition is switched on. I wait a couple of seconds until the pumps stop ticking as I know that the carb float bowls should now be filled. I then press the accelerator pedal to set the choke lever, take my foot off the pedal and crank the engine. It always starts virtually immediately on choke and idles at about 1200 RPM. After about 10 seconds I blip the accelerator and the idle speed drops. If the car has been parked up for a couple of weeks and I don't remove the wire from the oil pressure switch the car takes longer to start as the fuel level in the carb float bowls will take a while to rise sufficiently while cranking and there's a risk that my battery might drain.
When my Silver Shadow II (79) has been parked for a while, I turn on the ignition and move the gear selector to P, then the fuel pump starts. After that, just start as usual.
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