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Hot m42 will not start easily (318IS)

Posted: Fri Jul 12, 2013 12:58 pm
by mrjonchandler
Hi All,
Haven't posted for a while.

Had the IS out last night, cold start is perfect. Car has a new battery and fires up without a problem.

However, when the car is warmed up and been running for a while, if you switch the engine off and re-start, all the lights come on etc but it just cranks over. No throttle and it just cranks and cranks, eventually after a few goes it does fire but it's more of a splutter and it just about goes.

Can anyone help identify what to have a look at?
I've checked all the inlet manifold etc, all seeems ok.

Much appreciated.
Jon

Re: Hot m42 will not start easily (318IS)

Posted: Fri Jul 12, 2013 2:02 pm
by Brianmoooore
Leaking injectors is the likely cause of the problem. Check by connecting a pressure gauge, tee'd into the rubber fuel hose to the injector rail, and see how well it maintains pressure after the engine is stopped.

Re: Hot m42 will not start easily (318IS)

Posted: Fri Jul 12, 2013 2:07 pm
by mrjonchandler
Have you heard anything about a fuel valve in the rear by the fuel pump?
I read it could be that and that could be purchased as a repair kit?
Why would the injectors leak when the engine is warmed up and not on cold start?
Thanks
Jon

Re: Hot m42 will not start easily (318IS)

Posted: Fri Jul 12, 2013 2:17 pm
by Brianmoooore
Yes , I know about the valve. That's why I suggest connecting the pressure gauge.
If the pressure drops, the next test will be to clamp off the return line and test again.
If it's relatively minor injector leakage, the fuel will vaporise in the manifold as heat soak occurs, making the mixture extremely rich when you try to restart. With an engine that is allowed to cool, the petrol vapour will have had more chance to find its way out, and in a cold engine will be less volatile.

Re: Hot m42 will not start easily (318IS)

Posted: Fri Jul 12, 2013 2:39 pm
by mrjonchandler
OK, will try and get hold of a guage.
Great tips, thanks
Jon

Re: Hot m42 will not start easily (318IS)

Posted: Fri Jul 12, 2013 6:02 pm
by Brianmoooore