X5 3.0i Poor Start

[salenks]

Hello,

I was wondering if anyone can help me with the issue I've been having.

My 2003 X5 3.0i sometimes starts like it only fires up a couple of cylinders and then a second or two later, the rest of them. This happens occasionally, not every time. I also noticed smell of gasoline when this happens.
I have been having issues with the battery where the voltage drops to 12.3 V and from what I've heard, it should be 12.5 or more volts. This is not the original battery but a Exide 72Ah/720A and same happens with another battery which is Optima 50Ah/815A. Could low battery voltage cause this? Or what else could be the problem?


I added the recording of engine sound to youtube http://youtu.be/Zr1XXcx1YWs.

Little history of my X5:
-105,000 Miles
-Spark plugs changed at 95,000 miles (orignal installed)
-LPG installed (had to remove original battery because of this and place new battery in trunk side compartment)
-Replaced fuel pump with one for Opel vehicles (has 3.5 bars and BMW has 3 bars pressure)

I was told by a mechanic that this fuel pump will do the job but I am not so sure. I will probably get the original in a couple of weeks.

When the mechanic hooks up the computer to the car, there are no error codes regarding this problem. There are some error codes but those are normal when you have LPG installed.


Thank you all for your help,

Sasa

[SlickGT1]

If you smell fuel, you are not burning it. So start with the spark plugs. Coils would give error codes.

[salenks]

Thanks for your reply.

Spark plugs were changed about 5-10k miles ago with original ones. Forgot to mention that in the original post. Fuel probably smells because not all the cylinders fire up when the car is started.

[SlickGT1]

Ok. Could be your 3.5 bar fuel pump is flooding the cylinders.

What condition is your air filter in?

[salenks]

Thanks for your reply. Air filter (k&n) was cleaned about 2,000 miles ago but i will check it.

[SlickGT1]

Hmm. Disconnect your maf and try staring the car. Let us know if it starts better.

[salenks]

I will try that. I know i can't drive it like that since it is automatic. I also have a replacement maf that i paid 90$ for. I know it is not original but it is for my car. Maybe i can replace it.

Thanks.

What about the battery voltage. Could that cause the problem?

[SlickGT1]

deff could be.

Have you tried unlocking OBC, and running the voltage test while driving? Search here, use the search button on top, search for "Unlock OBC". instructions are easy and there. Then run the voltage test.

Report back what you observe.

Also, does it start fine after driving, or same deal?

[salenks]

I will try that. However, voltmeter says battery has 14V when car is running which means it is charging properly. Same deal after longer drive. Batteries are definatelly bad in my opinion. Warranty sucks here in Serbia though.

[SlickGT1]

if its same thing after a drive, I doubt its your battery. You battery was just getting charged, and still the same poor start. Is this the same for after short drives and long drives? Maybe you are only doing short drives, and not charging up the battery all the way?