Home  |  Forums  |  914 Info  |  Blogs
 
914World.com - The fastest growing online 914 community!
 
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.
 

Welcome Guest ( Log In | Register )

> Fuel Pump 2 seconds, Fuel Pump voltage
thompson-mfr
post Mar 14 2014, 12:40 PM
Post #1


Thompson, Ryan
**

Group: Members
Posts: 198
Joined: 30-September 08
From: Silverton, OR
Member No.: 9,598
Region Association: Pacific Northwest



I have a 74 2.0L original FI and the fuel pump has been moved to the front trunk. I converted to the in and out style (75-76).

My fuel pump used to go on for 2 seconds to prime, then off until cranking or running. I know this is how it is supposed to work.

Mine now is on constant with the key in aux position (before starting/cranking or running)

What controls this? The computer?

I also have only 7 volts to the pump and 9 volts at the fuse on the relay board that pump power goes through. Good 12+ volts at battery.

Finally to the question: Does the computer control this 2 second prime?
User is offlineProfile CardPM
Go to the top of the page
+Quote Post
 
Reply to this topicStart new topic
Replies
Tom
post Mar 16 2014, 07:57 AM
Post #2


Advanced Member
****

Group: Members
Posts: 2,139
Joined: 21-August 05
From: Port Orchard, WA 98367
Member No.: 4,626
Region Association: None



86 is the controlled ground for the fuel pump relay. Remove the relay and hook up a multi-meter to 86 and ground with the meter on OHMS scale. You should get continuity for about 2 seconds when key if switched on, then it should go to infinity. If this works correctly, check out the relay, it may have stuck to on. With the meter on OHMS check from 30 to 87A and you should get continuity with 30 to 87 being open. Anything else means a bad relay. You can open them up and check the contacts and perhaps clean them up.
Tom
User is offlineProfile CardPM
Go to the top of the page
+Quote Post

Posts in this topic


Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



- Lo-Fi Version Time is now: 1st June 2024 - 08:26 PM