E30 Zone

Hi Guys,

I have just bought an E30 325i (feels good to be back in an E30!) but it has a few niggles that need sorting....

Basically when i start the car first thing in the morning it turns on straight away but it cuts out straight away after firing up. When i try the second time it starts with no issues and is fine for the rest of the day. Looking about it seems to be a crank position sensor fault possibly?

The car has new leads, plugs, rotor arms etc and runs fine.

Any help would be great.

Any ideas? Im just worried about the fault becoming worse really.

I doubt it's the crank sensor if it starts up. What age is this 325i?

As was posted in a similar thread recently, it may be to do with the fuel system; particularly the pressure being held when left for a long time. A failing return valve inside the pump or a dribbly injector will allow the pressure to drop overnight, and while there'll be some fuel left in the rail to get the initial firing, it will then cut out as the pump has to recharge the system.

A good idea is to pull the injectors and send them to Injectortune for rebuilding. Even if it doesn't fix the problem, it'll claim back some power and fuel economy. Most injectors are long overdue a rebuild.

Thank you for your help, makes sense. It doesn't seem to be a huge hardship so i will get it done soon.

Any other ideas are appreciated! The engine does run a tiny bit rough when cold nothing major just not as smooth as when its warmed through.

I'm not entirely sure but might be worth checking for air leaks. What does your car idle at from cold? The wiki suggests about 1k RPM and 600-700 when warm.

Perhaps worth checking over this page and just search up stalling, there's about 6 things that it could be http://www.e30zone.net/e30zonewiki/index.php/Intake

Failing that I'm unsure, if you've a relay on the side of your fusebox check that's functioning correctly as I believe it's some form of cold start relay BMW installed as a bodge on some cars. My old 325i lump had one on it which played up a bit but I can't recall if it caused this.

It idles correctly, just a little hesitant when you first touch the throttle. Thanks for all the advice, I will start troubleshooting. It's not a huge problem so it'll be something I'll sort over time.

I would let it sit overnight and then power up the fuel pump either on the relay plug or the pump under the rear seat. Let the pump buzz away for a few seconds, refit the relay if you removed it and start it. If it starts and doesn't stall the problem is an overnight loss of residual fuel pressure in the rail. Most likely a dripping injector but could be the FPR.