'92 Loyale - Difficult to start, rough idle, and stalling/no power while in gear.

[SuspiciousPizza]

For SPFI models, the fuel pressure discharge from the fuel pump is 36-50 psi. After the regulator is 20-24 psi @ 700rpm. The regulator drops the high pressure from the pump to a usable pressure for the injector. So there is a high pressure side and a low pressure side, separated by the fuel pressure regulator on the throttle body.

Could be an issue with the fuel lines or filters. But most likely the fuel pump is tired and out of spec.

[cherrythesubaru]

Well wish I had done this check sooner! I'll see if I can find a pump and swap it out. 

Thanks! 

[cherrythesubaru]

Searching around for a pump that will work. My local parts store carries this pump: 

https://www.rockauto.com/en/moreinfo.php?pk=1111648

Thoughts on this being a viable replacement? 

[el_freddo]

I don’t know the SPFI well at all, are you sure the fuel pressure spec is 21psi? I thought it would be more inline with other EFIs like the EJs up at about 40psi. 

I’ve used the same external fuel pump for a NA MPFI EA82 and an EJ22. No issues. 

My thinking is that your fuel pressure is half of what it should be. This could be the fuel regulator or the fuel pump itself, or both. 

Pull the vac line for the fuel pressure regulator and make sure it doesn’t smell of fuel. If so, it’s dead. 

Cheers 

Bennie

[SuspiciousPizza]

Yeah that pump should work. Really so long as the pressure, voltage, and current draw are correct (the pump you showed looks to meet those specs) then these cars really don't care. 

I don't know if it'll last as long as an OEM or equivalent pump but it'll do the job. 

You may have to do some electrical work and figure out a mounting solution since this isn't an OEM equivalent pump but that's not a big deal and it's nothing too complicated. 

Sadly OEM/equivalent SPFI pumps are NLA but if you do ever want to keep a lookout for one, the part number is 42021GA242.

Good luck, let us know how it goes.

:]

 

 

[cherrythesubaru]

Ok got that pump installed. Still only getting 19/20psi from it though... going to inspect my fuel lines and blow some air through them to see if there are any blockages. 

[SuspiciousPizza]

Did you check that fuel filter down near the fuel pump? 

Too bad you had to go buy that pump but it'll give you more peace of mind in the future. Plus you can keep your old one in the car as a spare if you're ever in the situation you need it.

If you do have to replace any rubber fuel hoses, Codan makes hoses that are the right diameter and are very good quality. Check out Volksbolts, they've got a good write up on fuel hoses. If you ever need some reading material.

[cherrythesubaru]

I believe my model only has one fuel filter in the engine bay which I swapped out. 

I blew out the hoses with compressed air and reconnected. Didn't seem to make any difference. 

Out of curiosity, I pinched the outlet hose on the pressure regulator with my pressure gauge still attached (in line after the filter but before the regulator) and was able to get a reading of 40psi. With this in mind, could there be an issue with the fuel injector being stuck partially open and not allowing enough pressure to build for a correct psi reading in front of the regulator? 

 

[SuspiciousPizza]

I checked the troubleshooting table in the FSM for "Engine stalls after initial combustion". All the following are what it says for the fuel injector:

Poor contact at terminal (could be at the injector connector itself, an issue with the wiring in the harness, poor connection at the wiring harness connectors (large black connectors near the driver side strut mount), or poor connection at the ECU.

Performance characteristics unusual (maybe the mesh "birdcage" on the injector is dirty or it's sticking.) (To check if it's sticking, place the business-end of a screwdriver on the metal body of the injector and put the handle on your ear. Put voltage to the injector BRIEFLY LESS THAN A SECOND and listen for the "click-click". One click for power on, one for power off.)

Clogged filter.

 

I'd check the injector, mate. You've got a good pump, lines are clear, new filter, good regulator. Really the only other component in that fuel circuit is the injector. Maybe the mesh birdcage sieve is dirty? Either that or the injector is borked?

Injector resistance should be between 0.5-2ohm (measured on the connector on the injector). If the injector tests okay and is clean on the sieve/not sticking, check the engine harness for damaged wires or poor terminal contact. (I doubt it's a contact since squeezing hose has nothing to do with electrons)

:]