Crank but no fire first key turn, starts right up second key turn?

[Maxhouse97]

Symptoms in the title. Did some research and found this on E46 fanatics.

https://www.e46fanatics.com/threads/wont-start-1st-try-in-the-morning.986814/page-3

Tried to resurrect that old thread to see if it was the exhaust cam sensor but nothing yet. Any thoughts over here on root cause?

[Cbouts]

i had this exact issue. mine was fuel pump. replaced it with OE and started right up. After going through the process and doing research, seems like its a somewhat common issue.

mine was 18 years old. Night and day difference.

[yhp2009]

Do a pressure test before you spend thats an expensive part brand new

[Arith2]

Are you just putting the key in and turning it straight to start? An old fuel pump will take longer to prime. Try letting the beeps stop before you attempt to start it.

[Maxhouse97]

Yes fuel pump makes sense. I am trying to start it right away like normal. Thanks.

Just googled fuel pump replace - seems fairly in depth. However the car has 127k miles, and my theory is to replace parts with new if/when I have problems.

[dukeofchen]

This could also be a symptom of a starter motor going bad

[ATB88]

Yes fuel pump makes sense. I am trying to start it right away like normal. Thanks.

Just googled fuel pump replace - seems fairly in depth. However the car has 127k miles, and my theory is to replace parts with new if/when I have problems.

Fuel pump takes 15 mins, it's very easy to access.

[eacmen]

Fuel pump takes 15 mins, it's very easy to access.

Concur its pretty easy. There is a special tool that you're supposed to use but nobody does.

Spray with with PB Blaster and let it sit for 20-30 minutes before trying to remove it. Don't just hammer it in one spot, go around the fuel pump and try to get some decent impacts all around to free up any seize there might be in the threads. Just be patient if it doesn't start unthreading immediately. Try to drive it down to a 1/4 tank or less to make it less messy. If possible let it sit overnight to relieve the fuel pressure in the line before disconnecting it. Don't light a cigarette or anything while doing the job.

[heinzboehmer]

If possible let it sit overnight to relieve the fuel pressure in the line before disconnecting it.

You can also disconnect the fuel pump fuse and let the engine consume the fuel in the fuel lines.

[Cbouts]

Fuel pump takes 15 mins, it's very easy to access.

seriously, super easy process... get some towels to make sure you can clean up any leaks. hardest part is unplugging the pump (still easy) as it unplugs diagonally. look it up on YouTube. ShopLife does a good review on an E46.

New part is $400 from ECS. You own an old BMW, be ready to spend some $$.

[dl.m3]

If this only occurs on warm starts. Then it's your fuel pressure check valve. The fuel pump doesn't always prime on warm starts so if your check valve is bad then all the pressure bleeds off. On cold starts your pump will prime every time (audible).

[dukeofchen]

seriously, super easy process... get some towels to make sure you can clean up any leaks. hardest part is unplugging the pump (still easy) as it unplugs diagonally. look it up on YouTube. ShopLife does a good review on an E46.

New part is $400 from ECS. You own an old BMW, be ready to spend some $$.

Another option available is to use the radium engineering kit to swap the pump itself while retaining the original housing. I swapped an AEM 340LPH unit into mine a couple weeks ago and have been happy with it thus far, quieter than the old unit that was likely failing, but time will tell as far as longevity. Got away with it for around $170 if I recall correctly, doing the swap added an hour or two to the procedure for me.

[gabylonfive]

Another option available is to use the radium engineering kit to swap the pump itself while retaining the original housing. I swapped an AEM 340LPH unit into mine a couple weeks ago and have been happy with it thus far, quieter than the old unit that was likely failing, but time will tell as far as longevity. Got away with it for around $170 if I recall correctly, doing the swap added an hour or two to the procedure for me.

I recall reading awhile ago that a few folks had issues with the radium kit and the included electrical connectors arcing and melting (causing intermittent or total failure.) Do you know if this was ever addressed? I'm planning to replace my pump in one way or another soon and would rather do the radium kit if all the kinks were worked out...

[heinzboehmer]

I recall reading awhile ago that a few folks had issues with the radium kit and the included electrical connectors arcing and melting (causing intermittent or total failure.) Do you know if this was ever addressed? I'm planning to replace my pump in one way or another soon and would rather do the radium kit if all the kinks were worked out...

They updated their instructions (and possibly the connectors?), but I just soldered and heat shrunk mine instead.

[jdamore44]

If this only occurs on warm starts. Then it's your fuel pressure check valve. The fuel pump doesn't always prime on warm starts so if your check valve is bad then all the pressure bleeds off. On cold starts your pump will prime every time (audible).

Mine definitely has the problem only when warm. Where is the check valve and what is the P/N? Is that the fuel regulator on the filter? I replaced mine when I bought the car about 20k miles ago. Can it be bad already?

EDIT: 50's kid ftw :https://www.youtube.com/watch?time_c...ature=emb_logo