Is it needed for FI guys to let the fuel pump prime before start |
|
Porsche, and the Porsche crest are registered trademarks of Dr. Ing. h.c. F. Porsche AG.
This site is not affiliated with Porsche in any way. Its only purpose is to provide an online forum for car enthusiasts. All other trademarks are property of their respective owners. |
|
Is it needed for FI guys to let the fuel pump prime before start |
carcus |
Sep 20 2017, 10:47 PM
Post
#1
|
Member Group: Members Posts: 223 Joined: 16-March 16 From: Colorado Springs Member No.: 19,760 Region Association: Rocky Mountains |
Just wondering. I have Bosch FI at Colorado altitude. My car will not start up right away unless I turn the key and wait about 10 seconds for the fuel pump to prime. All plugs and wires new, new fuel pump, and fuel filter. Moroso electronic conversion. New battery. I try to drive the car once a week. Just looking for advice. Car is a 1976 2.0 with 1973 2.0 engine. OEM fuel injection.
|
Dave_Darling |
Sep 21 2017, 11:11 AM
Post
#2
|
914 Idiot Group: Members Posts: 14,990 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California |
I don't think that valve in the photo is a check-valve to maintain pressure in the system. It is in the return line, not in the supply line. Remember that the high-pressure part of the fuel loop goes from the fuel pump to the fuel pressure regulator, then dumps back into the tank with essentially no further restriction. The return port on the pump is Y'd into the return line, but there should not be much pressure in that line regardless, so the valve shown is not relevant.
The rotor and pucks of the pump body serve as a check for fuel trying to flow back through the pressure line to the tank. The fuel pressure regulator serves as the check valve on the other end. Either could allow fuel to bleed past; I am thinking that it is more likely to happen on the pressure regulator side than the pump side, but that really is a guess. BTW, the "key on and off a few times" does not work on an L-jet car. The L-jet pump, as stated, only runs when the starter is cranking or the engine is running. --DD |
Lo-Fi Version | Time is now: 21st May 2024 - 10:21 PM |
All rights reserved 914World.com © since 2002 |
914World.com is the fastest growing online 914 community! We have it all, classifieds, events, forums, vendors, parts, autocross, racing, technical articles, events calendar, newsletter, restoration, gallery, archives, history and more for your Porsche 914 ... |