View Full Version : Extended cranking after fuel pump replacement

11-12-2014, 11:57 AM
Has anyone had this issue? Fuel pump just up and died one day. No previous issues with starting. Had pump replaced and now engine cranks for 3 to 4times longer than normal before starting after sitting for 45 mins plus. Taking back to shop tomorrow but wanted some info to try and assist. Thanks

11-12-2014, 12:17 PM
can be your battery....

11-12-2014, 01:23 PM
It cranks just fine.....it just takes a long time to fire. thanks for the comment.

11-12-2014, 01:29 PM
Sounds like the replacement fuel pump has a lousy check valve. All your pressure is leaking down over time.

Question: Does the cranking get progressively longer, based on how long it sits? (ie: sits for 1 minute, restarts normal. Let sit for 5 minutes, cranks for 3 seconds. Let sit for 10 minutes, cranks for 6 seconds).

If so, that would indicate the pressure is leaking down through the aforementioned lousy check valve on your chinese aftermarket fuel pump. The right fix is to install a new pump with a good integral check valve. I'd recommend a VDO pump. The alternative quick-fix is to slap an in-line check valve on the pressure line and call it a day. There was a retrofit kit made of pure OEM BMW awesomeness for the older 5 series cars that was very popular for this "quick fix" type situation. Alas, that kit is no longer readily available. Link to said awesomeness:

Getting back to the point: Basically, this here has happened to you. (http://www.audizine.com/forum/showthread.php/610635-Fuel-Pump-Not-holding-pressure-2-cranks-to-start)

11-12-2014, 01:33 PM
The cranking does get progressively longer as the car sits.

11-12-2014, 01:55 PM
Edited above post a bit.

11-12-2014, 04:39 PM
Try priming it a couple of times before starting. It could also be a loose/torn fuel pump hose.

11-12-2014, 04:43 PM
look on amazon. they may have a check valve you could use.

11-13-2014, 06:19 AM
Thanks everyone. Back at the shop today. Not sure of the brand they put in but price wise it wasn't cheap....$260 just for the pump. Will update later today....