petrol pump v8 110

If I have understood the system correctly the pump is designed to provide a constant flow with a return to the tank.

When the previous owners had an lpg conversion fitted a solenoid operated valve was fitted to the feed pipe.

When on lpg the solenoid closes the feed pipe so the pump can not create a flow.

Would this be the reason a new petrol pump has failed after just a few hundered miles?

Gerald

Reply to
Idris
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Yes. (If I understand correctly what you are describing) When on LPG the pump should be switched off, I would have thought - if it is, this is not the reason). JD JD

Reply to
JD

Maybe the signal has a 'live' output from the controller, if so they could have fitted a relay to de-energise the pump supply when on gas.

Martin

Reply to
Oily

Thanks thats much as I thought. Currently the pump is live both on petrol and on LPG and hence probable cause of failure.

Gerald

Reply to
Idris

Tis on mine too and that hasn't failed yet. I thought it was just a centrifugal pump so assumed stalling it would cause no problem. The benefit of having a pressure in the petrol feed line is to quickly fill the float bowls. I also thought the re circulation was to cool the carbs.

AJH

Reply to
AJH

I seem to remember seeing reports of the pump failing if you run with an empty tank as the pump relies on the petrol to cool it. Disabling it hen the lpg is on seems to be a sensible move.

Reply to
Bob Miller

I would expect it to be more a problem of the bearings running dry, I keep petrol in the tank, just in case. I sometimes have problems with hot starts on lpg.

It looks easy to isolate the pump as there is a connector block on the top of the bulk head, this could be replaced by a solenoid activated off the lpg switch.

AJH

Reply to
AJH

On or around Wed, 18 Oct 2006 09:54:05 +0100, AJH enlightened us thusly:

If it's a continuous flow system, as per the rangies and discos with efi, they have a return pipe I think from the accumulator thing (book's outside) but anyway, the pump runs all the time and generates fuel under pressure in the feed pipe, with the remainder going back to the tank. This kind of pump can be left running - the normal way to convert the EFi ones is to interrupt the injector signals.

However, some of the 110s had an SU type pump which only runs on demand. The coninuos operation ones could have a solenoid valve in the supply to the carbs, if the carb isn't part of the return circuit, which is unlikely.

Reply to
Austin Shackles

The solenoid currently stops the flow before any pipe branches so stops all flow. Am trying to decide whether its best to put in an electrical relay to ensure pump is only switched on when on petrol, or to move the solenoid valve so that the return is allways open and a branch to the carbs is solenoid controlled.

Gerald

Gerald

Reply to
Idris

Go for the option that turns the pump off - it's how we've always done our installs and has never caused any problem.

Reply to
EMB

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