new fuel pump that i had gotten off of ebay weren't quite right....
Since i installed it ,the tank,filter and injectors, I was having the usual hot start problem with 3 trys to start it when hot soaked...
I checked the fuel pump pressure and it was good but instantly went to zero,when shut off, I thought to myself it could be the fuel pump check valve, or the fuel pressure regulator letting fuel drain past, or a number of leaking injectors. So i deadheaded the pump by pinching off the return line from the regulator and briefly cranked the engine, gauge shot up above 70 and then when i stopped cranking instantly went to zero
That pretty much confirmed it. So i installed the bmw retrofit check valve kit 16 14 9 068 988..... pretty cheap from Patrick at bma, less than 10 bucks. Nice kit ,comes with checkvalve, fuel line, hose insulator, hose crimp clamps and plastic nut covers to get rid of sharp edges on the pump cover.
Last edited by Bill R.; 02-08-2009 at 05:42 PM.
Thanks a lot Bill. Nice pics, I needed that too for my website and there are offten question about that, and will borough that and mention your name, if you agree.
My collection so far
http://i230.photobucket.com/albums/e...t/IMGA0609.jpg
here non-BMW http://members.cox.net/zmuff/crop%20...lve%20done.jpg
installation pics E30
http://www.bimmerboard.com/forums/posts/496880/
When yo talk to Patrick at BMA, tell him the pic does not work.
Used with the search there with the part number, 16149068988 CHECK VALVE KIT
Last edited by shogun; 06-25-2016 at 07:36 AM.
Q1) Why a bad gas check valve is this hard starting problem source only when engine hot, not also when it's cold ?
Q2) Does this check valve kit add a second check valve in serie with the pump, why not just replace the existing one ?
Glad to see that it solve the problem easily and cheap.
When hot, the fuel will boil in the fuel rail by the injectors creating an air lock or vapor lock when you have it under pressure it raises the boiling point and also gives it no place to go. On a cold start the fuel is denser and the pump fairly rapidly gets to the injectors , but it still starts faster with a good check valve.
Q2, it takes less than 5 minutes to install the check valve start to finish and doesn't hurt to have 2 in series, its a lot more trouble to pull the fuel pump out of the tank to replace the check valve. This was a cheap 88.00 ebay pump so for less than 10 more it works fine now.
Bill R,
How exactly did you hook up the check valve. From the picture I can't see now you tapped into the send line?
Erich, next time i order from bma i can check for you if you want. How many would you like? I can check my local dealer also, I have to pick up some e46 parts from them in the next couple of days anyway.