fuel pump surging, why?? |
|
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. |
|
fuel pump surging, why?? |
Tab914 |
Aug 1 2005, 06:52 PM
Post
#1
|
Member Group: Members Posts: 158 Joined: 25-April 04 From: Alexandria, Ontario, Canada Member No.: 1,978 Region Association: Canada |
Another one for you guys...........
Here is the problem I am trying to fix. Whenever the needle in the temp guage gets to about 1/4 the fuel pump starts surging. This causes the idle to start to go up and down in rythm with the fuel pump. Also when under load the car stutters and shudders and kinda wants to choke. Before the car gets up to that temp. it runs nice and smooth, strong on acceleration and no poping or backfiring on decel or anything. Just sounds great and runs fine. Idle is where it should be and fuel pump does not surge. Here is what has been done. -Valve adjustement -Dwell adjustement -Timing adjustement -Tested MPC as per proper ohms. Parts I have changed- coil, plugs, ignition points, trigger points, condenser, rotor, cap and wires. Questions:- what could make the pump surge like that? -does it make a difference how the MPC wire goes into it's conector? -How do I properly check the head temp sensor. -Could the intake temp. sensor be the cause. I am at a lost. Feel like I am going in circles. (IMG:http://www.914world.com/bbs2/html/emoticons/confused24.gif) Has anyone had this kind of problem?? Desperate for advice. (IMG:http://www.914world.com/bbs2/html/emoticons/sad.gif) Thanks, Dominic. forgot to add. car is a 1974 2.0 with stock fuel injection. |
Dave_Darling |
Aug 1 2005, 07:57 PM
Post
#2
|
914 Idiot Group: Members Posts: 14,991 Joined: 9-January 03 From: Silicon Valley / Kailua-Kona Member No.: 121 Region Association: Northern California |
The air will get purged without any extra effort on your part. The bubbles will (eventually) wind up in the return line, and go back into the fuel tank.
Not sure what's going on with the pump being intermittent. I would suspect the pump, the wiring to the pump, the pump relay on the relay board (especially that!!), the relay board itself, the connections to the relay board, the fuses on the relay board.... Hmm, not sure what else offhand. The trigger points, because they tell the EFI that the engine is still running. --DD |
Lo-Fi Version | Time is now: 6th June 2024 - 05:06 AM |
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 ... |