Hesitant Start

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Mitchen
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Post Tue May 19, 2015 6:40 pm

Guys an issue with my B20. When I turn the car on, most of the time it needs me to put my foot on the accelerator and rev the car to get it going, otherwise it'll just rumble for a couple of seconds and die, or just won't start at all. Used to happen rarely for example when I hadn't driven the car for a few weeks, so I thought it was just blowing the cobwebs off.

Had a thread about this before with people suggesting it was the TPS.. but that's been replaced so can confirm it's not that. I'm think a fuel pressure issue... perhaps the regulator?
1990 320i Coupe SE

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DaniTD
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Post Tue May 19, 2015 6:46 pm

If happens with somewhat long periods of non running, it sounds as you said like a faulty fuel pressure regulator. You can check too if its leaking so it would slowly drip fuel into the intake manifold losing pressure. To do that, with the engine running, disconnect the vacuum hose that goes to the fuel pressure regulator and see if it drips fuel. It can take some time after you retire the hose, maybe you could smell raw fuel too. Another way is to replace the vacuum hose with a transparent one and see if you can see drips of fuel being sucked.
Mitchen
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Post Tue May 19, 2015 6:51 pm

Can't smell fuel around there at all, but I shall give this a crack! Cheers Dan
1990 320i Coupe SE

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Brianmoooore
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Post Tue May 19, 2015 6:54 pm

I agree that it's probably fuel ending up in the inlet manifold, but the most likely mechanism is via leaking injectors.
TPS not only needs to be working, but needs to be adjusted correctly
Mitchen
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Post Tue May 19, 2015 6:58 pm

Injectors refurbished and installed correctly by Barry, as well as TPS being set up correctly with the click.
1990 320i Coupe SE

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Brianmoooore
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Post Tue May 19, 2015 7:01 pm

First thing to do is get a fuel pressure gauge connected up and see what happens when the car is parked. If the pressure does drop off, you need a couple of clamps for the fuel hoses to narrow things further.