 FI Challenged Individual Checking Fuel Pressure, and a question re: fuel pressure regulator |
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| 76-914 |
 Mar 23 2009, 10:56 PM
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Repeat Offender & Resident Subaru Antagonist  Group: Members Posts: 13,876 Joined: 23-January 09 From: Temecula, CA Member No.: 9,964 Region Association: Southern California 
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Trying to teach myself about FI. Bear with me! Does it matter where you check the fuel pump pressure i.e. before or after the pressure regulator? Secondly tell me if I got this right: 76 2.0 GC series engine; Fuel leaves the tank, flows thru fuel filter to pump where it is pumped to the passenger side fuel rail the over to the drivers side fuel rail. One branch on this fuel rail feeds the cold start valve while the other branch goes to the pressure regulator. If pressure exceeds appx 35psi then excess is bled off and routed back to the tank outlet/pump inlet junction??? Is this how it works???? Thirdly, does Pelican rent a gage? I took a water pressure gage (0-60lb) and checked pressure on outlet side of PRV. It pegged the gage so I'm thinking wrong gage/wrong side of PRV or pump is on steriods. Can ya hep me?
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| 76-914 |
Mar 25 2009, 03:25 PM
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Repeat Offender & Resident Subaru Antagonist Group: Members Posts: 13,876 Joined: 23-January 09 From: Temecula, CA Member No.: 9,964 Region Association: Southern California
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(IMG:style_emoticons/default/headbang.gif) OK. Retested at "test port" and pressure was appx 31 on a 10yr old air gage so I'm guessing the pump is good and at some point I need to get a better gage and set the pressure correctly. I should mention this car was not running, 53,000 original and found that the pump relay not working. Jumped relay (#30 to #87) to complete pressure test. This is where I am getting confused. I don't have power to #86 so I wanted to trace it down. Looking at my Haynes (black&white flow chart on pg 181(which says it is for 75 model year-no listing for 76 here) I find J17 (pump relay) and follow #86 to the ECU where it connects to terminal 19. What color is this wire so I can find it outside of the ECU or relay board. Wouldn't I need to disconnect this wire to check for ground at terminal 85, anyway? Now, 2 questions about rennlist statement below. What controls the 1 1/2 second activation of the relay. If it turns off doesn't the pump stop? And secondly, I don't understand the last comment about switching the key on/off. how many times? Once, five times? What happens then? Or did they mean turn switch to off position before replacing ECU? And what is meant by "If no ground is available to wire 19 ............"? I thought #19 was a hot (12v) wire. Is 16/24 off the ECU the neg switch for this circuit.
NOTE: Relay is active for only about 1- 1 1/2 seconds after the ignition has been switched on. Check with voltmeter; relay is wired from ground through control unit. Do not connect terminal 85 to ground without first disconnecting wire 19 leading to the control unit, otherwise the control unit will be damaged. If no ground is available to wire 19 (switch ignition on and off), replace control unit. |
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Posts in this topic
76-914 FI Challenged Individual Checking Fuel Pressure Mar 23 2009, 10:56 PM
SLITS Tank .... fuel filter ..... pump .... passenger si... Mar 24 2009, 06:56 AM
type47
Pressure should be measured at tap for cold star... Mar 24 2009, 07:21 AM Bleyseng or if its pegged it could be a pinched return hose... Mar 24 2009, 08:08 AM SLITS Sorry I didn't fully read the post .... You sa... Mar 24 2009, 10:53 AM underthetire If you are new to FI, i suggest you read all of th... Mar 24 2009, 11:19 AM McMark :agree: Check fuel pressure at the CSV port.
If f... Mar 24 2009, 01:03 PM 76-914
:agree: Check fuel pressure at the CSV port.
If ... Mar 24 2009, 10:43 PM 76-914 Hot Damn this is some good information. Dead head ... Mar 24 2009, 10:21 PM McMark
That's a good way to get it right. But getti... Mar 25 2009, 11:22 AM 76-914
That's a good way to get it right. But gett... Mar 25 2009, 03:29 PM |
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