Difficulty starting 325i

Post Sun Feb 24, 2013 2:25 am

Hi all,

I recently replaced the blue temp plug, fuel pump, and fuel pump relay. Still, it takes about 10 tries to actually start, and then I have to hold the throttle open for about 3 minutes before it will idle. I've checked the spark plugs; they're not fouled. A mechanic checked compression and that was OK too. It's not throwing out any diagnostic codes either.

It seems to run a bit rich at start, the exhaust is pungent and gray, but it goes away after the engine warms up. (It's not condensation.) I believe the ECU was replaced with a Dinan chip by the previous owner... but the car has been running fine for the five years I've owned it.

When I actually get the car running, it drives perfectly.
Any ideas on why it's so hard to start?

Post Sun Feb 24, 2013 1:40 pm

Check inlet manifold gasket for air leaks; with engine idling, spray WD40 around the gasket and if the idle speed increases, you have a leak, so need to fit a new gasket.

Also check for any splits in the hoses around the throttle body, and clean and verify that the TPS is working properly. Same goes for the ICV.