Rover 25 poor starting - Thanks to David

A leaking injector is quite easy to diagnose as the rail pressure will drop quickly when the pump isn't running.

Re-con injectors will likely also have a better spray pattern than old ones, so could aid starting.

I can't be sure, but I think my bloke said he'd checked fuel pressure, but perhaps he didn't wait till the morning ! The injector seller certainly say they check the spray pattern etc. but whether a poor pattern could prevent it starting at all one or two times but then apparently run perfectly well, I don't know.

I'm just delighted it seems reliable again. :-)

Great news. :-)

Thanks for the update, and you're welcome.

David

You don't need to wait long. If the leak is bad enough to have an effect on the running, it will show up pressure wise instantly. It has to be pretty bad to effect the running appreciably.

It was bad starting from cold, not bad running.

David

Yes, it had apparently no effect after the first start of the day.

Well yes. The combination of a leaking injector and the pump not producing full pressure while cranking due to low volts, can result in a weaker mixture than as programmed.

Well I know he did test the cranking voltage and battery in general - it's quite a new battery, though I realise that's not a guarantee. Could be the pump I guess, but generally running is OK. Anyway, I'm a happy bunny for the moment.

Normally with a perfect system, the pump runs when you switch on so builds up the pressure to max - if there's no leaks. When cranking the lower volts does make a slight difference to the pump's maximum pressure, but should be catered for by the ECU mapping. However, with a leak, all bets are off. But it would vary from car to car anyway.

But if the injector has been leaking, then the result is similar to a flooded engine, hence the poor cold first start.

David

It tends to have a localised effect on that cylinder which doesn't compensate for the weaker mixture to the others.

I do not think that that car has direct injection, so I think the leak would be into the manifold affecting all cylinders and the inlet tract, causing difficult starting.

David

Well it's got four injectors, but if there is leaking and they're not that reliable, perhaps there's several failing. Anyway, it's still starting first-time and I'm confident it cured the starting issue one way or another. I wonder if it might also improve consumption a little, because I think it's deteriorated of late, dropping back under 40.

Thanks.