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Posted by: 76-914 Sep 8 2016, 08:43 PM

A month back I installed a digital fuel pressure (FP) gage and when the car died due to low and then down to no fuel pressure, I suspected the fuel pump. I confirmed that the fuse was good and replaced the pump. Turned the key and nothing. I failed to check for the presence of voltage at the pump connection. Idiot. Must have been the relay. So I reach up behind the AC and un-clip it. Bench test it w/ a 9v batt and ohm meter. Test ok! Hmmm, Still no power at the pump. Well lets plug it back in and check for bad connections on the molex plug. Then I notice that when the FP relay was energized the 12v side leaving the relay was @ 5v. Turn the key off and check the hot side of the relay and it reads 12v. At this pointe I'm speaking in Tongues and I'm pretty sure that I ended up in a Fetal position. What in the Hell is going on? Then I remembered what that relay served. This little Bastard. The fuel pump controller.



So I dropped the AC and pulled the console just to access the FPC. It was in a great place before I added AC. Once I removed the controller from the circuit I got 12v at the relay outlet. All of the turbo WRX's used one but only one Subaru EZ30 used one; mine, the 2003 YM. I had noticed that my fuel pressure varied with acceleration and that's what these do. I looked into bypassing the controller but decided Subaru knew better than I so $160 later I'll have one in a few days. Because mine is a "one year only" I had to order from the dealer. Otherwise, they're $35-$45 a pop on Ebay.
The carnage. Not as bad as it looks. I can have it back together in an hour.

Posted by: 11tenths Sep 9 2016, 08:17 AM

When I scrolled down to that picture I involuntarily jerked back two feet to a defensive position...

-Harry

Posted by: Mblizzard Sep 9 2016, 10:47 AM

I can put that back in 4 beers!

Posted by: rhodyguy Sep 9 2016, 01:31 PM

let me know when to start the stopwatch on those 60 minutes.

Posted by: JOEPROPER Sep 9 2016, 01:40 PM

Posted by: Mblizzard Sep 9 2016, 04:11 PM

QUOTE(rhodyguy @ Sep 9 2016, 11:31 AM)

Posted by: 76-914 Sep 9 2016, 06:44 PM

It came in today and I took the dogs with me to pick it up. Hope my diagnosis was correct and it isn't the ECU. It may take a bit longer than an hour but not too much more.One of the benefits of modifications. You end up doing everything 15 times so you end up with a :stromberg:load of experience.

Posted by: 76-914 Sep 10 2016, 03:32 PM

Well Fuch me to tears. That twern't it neither. So I ordered another ECU. What's another $80. I've already thrown about $300 at this so far. I decided to verify what I already knew. Sound familiar? I was now getting 12v on both sides of the pump relay load side so I decided to bypass the controller and feed straight to the pump. Snip/snip, wire nuts, turn the key and nothing. Verify voltage; 12v, yep. Hmmm. Maybe the pump plug in the tank came loose? Pulled the pump, dried the gas and jumped it at the batt. Bingo! It came to life. I take it back up front and jump it directly off of the fuse block. Nothing! Check voltage and it's now 3.87. BTW, did any ya'll hear a thunderous roar coming from southern California about 9:30 this morning? I turned the air BLUE. This 6 circuit fuse block is connected to a 4 pole distribution block. The distribution block is supplied by 2 wires. One 10ga & one 8ga. I connected the pump directly at this distribution block on the 8ga (same circuit) and nothing. Moved it to the 10ga wire and the pump came to life. Huh? Checked the voltage at both wires and the 8ga is "0" now. It runs undisturbed thru the tunnel to a main distribution fuse block in the engine compartment. I tested that fuse; good. 12v on both sides of the fuse, too. So I move the test probe a hair to the right and check the 8ga wire and it's "0". Ahaa you Son of a Bitch, I got ya! Power coming in the fuse box on this circuit, the fuse is good and there is no voltage where the wire connects???????? This is what I found:

This is the power distribution source since the conversion. The starter circuit is separate. It is supplied by a 4ga wire that enters on the left bottom. There are 2 10ga wires and 1 8ga wire that exit on the right side. The fuses are removed in the pic's. This is the front side. The questionable circuit is the middle one.



And the backside:



But look very closely at the middle, right side. See all those bubbles in the plastic. Looks like a mfg defect. Bottom line is; sometimes I got a connection and it varied. Any load applied basically changed any voltage readings I had previously taken. I thought I was going Mad. This is where an experienced mechanic's knowledge would have really helped. I assumed the presence of voltage was adequate. An experienced mech with the correct meter would have checked for amp draw and had this diagnosed in 20 minutes. So I now have a spare 3.0 engine, ECU, fuel pump, FP controller and a neglected 4 cyl 914 sitting in my garage.

Posted by: Chris H. Sep 10 2016, 04:26 PM

I hope you're out thrashing that thing just to be sure it's fixed. Seems like that's it. Hope so. I though fuel pressure regulator since it was intermittent.

Posted by: 76-914 Sep 11 2016, 06:16 PM

Put it back together and started it this PM. 71psi @ start up.



I ordered another fused distribution box. I piggybacked 2 on the lower circuit until the replacement box arrives. Geez,, a month down time. Putting this one to bed!

Posted by: potomacmidget Sep 11 2016, 07:39 PM

QUOTE(11tenths @ Sep 9 2016, 10:17 AM)

Posted by: Elliot Cannon Sep 12 2016, 11:36 AM

I went out to my 914 yesterday morning, opened the engine lid and looked at my carbs. Got in the car. It started right up and ran great all day. I just thought I would inject some joy to an otherwise depressing thread.
Cheers, Elliot

Posted by: Toast Sep 12 2016, 03:25 PM

Posted by: 76-914 Sep 13 2016, 08:41 AM

QUOTE(Elliot Cannon @ Sep 12 2016, 10:36 AM)

I went out to my 914 yesterday morning, opened the engine lid and looked at my carbs. Got in the car. It started right up and ran great all day. I just thought I would inject some joy to an otherwise depressing thread.
Cheers, Elliot