1991 Legacy ECU Swap to change to Red top injectors.

[none77]

I want to swap the fuel rails and injectors from a newer Legacy onto my 1991 Auto N/A Legacy wagon.

I have read a lot of different posts, and I'm under the impression I need to swap the ECU from a newer car for the red injectors to work properly.

I'm trying to figure out what years I can swap. I found some injectors, rails, and Fuel Pressure regulator from 1995 Legacy today at salvage yard. The car was missing the ecu....

I live in Northern KY/Cincinnati Area and I don't see many of these cars at salvage yards.

I saw some other posts that seem to suggest 1992-1994 ECU would be direct fit.

Thanks in advance!

[86BRATMAN]

You can use any na 92-94 ecu, but you'll need to grab the plastic maf from the same car as well. The 95+ legacy ecu will not plug into your wiring harness.

[none77]

Great! I'm not 100% what you mean by "Plastic maf," can you elaborate. Sorry, to be such a Noob.

Thanks Again!

[86BRATMAN]

The mass air flow sensor, yours now is metal and won't work with the 92-94 ecu. The one you need is a plastic body, you can grab the maf sensor from any 92-98 legacy/forester to use with your new ecu.

[none77]

I have a MAF Sensor from 1993 Legacy on my car now. It actually looks exactly the same as the one I took off. The out side is definitely plastic.

I swapped it when I was trying to determine why my car was running so poorly with defective injectors. I was under the impression that it would work with my 1991 Stock Set-up. My car is driving great, but is a little hard to start, and gas mileage isn't great.

I was having a terrible time finding the Grey Injectors, and the ones I purchased from Bostech made the car not drivable. I read several posts, and decided I would switch to Red Top Injectors. They seem to be plentiful at Salvage Yard. The posts I read suggest car drives better, and gets better gas mileage with correct ecu.

[mike-tracy]

I was in the junkyard the other day and noticed all but 1 1st gens had the plastic Maf. The 1990-94s had em, only one with an aluminum Maf was a very early 1990 with an 1989 build date and Japanese VIN. I've been guilty of directing people towards grabbing a metal Maf off 90-91 cars before (because the person who gave me that info was trustworthy), but when I looked myself it turns out only really early 1990 NA's had em.

I was there for AC parts and the differences between the cars was also staggering. The early 1990 had a unique ac pump (by diesel kiki) and differently bent lines. Late 90 had calsonic, 91 had zexel, 92-93 had same setup as late 90, but different electrical plug, 94, was unique again with the 1 year only r134... It felt very un Subaru like.

That being said, if you find a 1st gen with red injectors, it should be safe to grab the ecu from it.

[wtdash]

It felt very un Subaru like.

'90-'91 ('91 transition year??) manual / 5-speed transmission non-turbo Legacys had the same HITACHI MAF as the '91-'94 turbo models.

All others had the plastic, green label JECS/AUTECS MAF.

My '90 AT had the JECs MAF and gray injectors.

The '92-'94 non-turbo ECU should be the correct one to run the reds.

TD

[mike-tracy]

The 91 I pulled parts off had a plastic Maf, as did thr late 1990. Both 5mt. I promise

[Nohbdy]

I have only ever seen the plastic MAF and I've seen them from Japan and Lafayette (Yey hometown wins) and they've ranged from 89-94 in the salvage yard so I'm over here going "what metal MAF??)

[86BRATMAN]

Weird, I was going by what I've always read. And that I had a 90 5mt LS years ago that had the metal maf. No idea what it's build date was.

[none77]

I was at local Salvage Yard yesterday, and the oldest car they had was 1995 Legacy. They only had 5 Subaru's in the entire place. I was there a few weeks ago, and they had a 1993 Legacy that I took MAF from, and they had already crushed it.

[86BRATMAN]

How pressed are you to do the ecu swap? I know where a couple 1st gen's are that will have the right ecu, but it may be a week or 2 before I can get time to go.

[none77]

I'm not pressed... car is running fine, but I'm running 2 black tops, and two grey tops. So, I feel like I'm on borrowed time.

I grabbed the fuel rails off a 95, but I was reading multiple threads on replacement, and I'm not sure they will work. Has anyone ever swapped Fuel rails from 95 legacy with 2.2 onto 91 with original Grey top injectors and angled tops?

[wtdash]

Hi,
The main thing is the metal spacers, I believe. They look like thick washers and sit on top and bottom of the rails on SOME of the fuel rails. I don't recall exactly which models.

I don't think the '95 would have them but the '91 might. And the next question is whether to use the '91 washers (if they're there) w/the '95 rails - sorry, I'm not 100% sure.

Did you leave the FPR attached to the passenger side rail? It can be reused w/the '91, too.

TD

[James614]

Those metal spacers are the devil! I had never seen them mentioned anywhere prior to my fuel rail swap and they love to drop down under the intake manifold. I wound up having to tape them to my rails for install.

/rant.

[none77]

I didn't see any metal spacers on the 1995. I could go back to junkyard, and look. When, I was at the junkyard a huge thunderstorm blew in and distracted me.

I have never removed the fuel rail from my 1991, but it's stock. If it had spacers, they will still be there.

[86BRATMAN]

I've not seen a second gen legacy with the spacers, but the manifolds are slightly different on them than the first gen.

[mike-tracy]

My 91SS had spacers, and my very early 90s legacy ej20g manifold had the spacers. I haven't seen them on anything newer.

[none77]

If I use Rails from a 95, will i need to use the spacers?

Thanks for all the help!

Lou

[wtdash]

Thinking about this.....I'm running 'newer' rails from a '95-'96-ish Legacy (I have bigger injectors for my turbo mods), and I reused the spacers on my '93 intake. So, use the spacers w/the 'newer' fuel rails. Spacers should stay w/the manifold, regardless of the rails involved.

Make sense?

TD

[James614]

I agree with that from my experience. I have ej25D rails which had no spacers originally, but needed to reuse the ones from my manifold for them to fit right.

[Legacy777]

The metal MAF sensor should have come on the 90-91 MY manual transmission Legacies while the black plastic MAF sensor should have come on the 90-91 MY automatic transmission Legacies. I have a tech book at home that states this.

Regarding the spacers for the fuel rails, they are dependent on the intake manifold not the rails. If your current manifold does not have the spacers, swapping the rails shouldn't cause you to need the spacers.