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another problem in my saga of replacing my 372,000 mile 93 legacy engine with a donor junk yard unit (65,000mi. verified). The donor was a 2.2, but the wiring harness was different than my motors. Harness switching time. So I labelled all the plugs with duct tape labels and used a permanent sharpie to write where each injector plug went. My gas laden hand happened to have smeared the passenger sides injector ID's. SO I had no idea which passenger side injector plug went front and which went rear. I've tried driving the car but can't tell any driveabilty difference, but I don't want to be dumping gas in at the wrong stroke and be thinning my oil out. HOW do I rectify this and make sure I've got them straightened out. I figured I would be able to feel a driving difference but nada.

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what's weird is that I can't discern any difference in how the car drives. Each spark plug is doing it's thing, but there is a 50% chance that the passenger side fulel injectors are squirting out of sequence. Since it's a fourstroke, the fuel is getting in there but out of sequence.

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Earlier Subaru MPFI was not sequential, and I doubt that the Legacy uses sequential. I have read stuff that talks about how sequential could only be a benefit at low rpm... higher rpms require the injectors to be open for longer than intake valve duration.

 

I would bet that your injectors are gang-fired, so connection would not make a difference.

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Just an fyi on the wiring harness thing.

 

The 90-91 engines had a three plug electrical harness, while the 92-94's only had a two plug harness. This was the problem you ran into correct?

 

As for which injector is which. I can take a look at the factory manuals when I get home, or you can look through the one I posted in your other thread.....or was that someone else's thread.

 

Here's pics from my injector swap. Maybe you can find a clue about which connector goes where from them.

 

http://www.main.experiencetherave.com:8080/subaru/images/injectors

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yeah, the donor had a 3 plug and my 93 had a 2 plug. Since the number of connections was the same on the engine, what was the 3rd. plug for. donor had 65k documented miles. switched the harness. Only problem is the off idle response seems kinda rougher, maybe some injector cleaner? still can't discern a difference in seat of the pants when switching passenger side injector connectors. The injectors are tilted at an angle wheras on my 93 the were at 90 degrees to the head. I'm hoping a 90-91 engine with my 93 harness will not give me any headaches. First day seems that the gas mileage is worse though, maybe from the injector plugs not being on the right injector. I did notice that one injector plug wire has a white band on the wire- can'tfind any info on whether that should be the forward or rear passenger one. Any things, other than the harness that I should swap with my 372,000 mile motor? thanks again to all.

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yeah, the donor had a 3 plug and my 93 had a 2 plug. Since the number of connections was the same on the engine, what was the 3rd. plug for. donor had 65k documented miles. switched the harness. Only problem is the off idle response seems kinda rougher, maybe some injector cleaner? still can't discern a difference in seat of the pants when switching passenger side injector connectors. The injectors are tilted at an angle wheras on my 93 the were at 90 degrees to the head. I'm hoping a 90-91 engine with my 93 harness will not give me any headaches. First day seems that the gas mileage is worse though, maybe from the injector plugs not being on the right injector. I did notice that one injector plug wire has a white band on the wire- can'tfind any info on whether that should be the forward or rear passenger one. Any things, other than the harness that I should swap with my 372,000 mile motor? thanks again to all.

wait wait.

 

So you swapped the injectors over too? You're running the 91 injectors on your 93?

 

The injectors will work, however the ecu's for the 90-91's are not setup the same. The duty cylce is different or something is different with the injectors. If you did indeed swap injectors, you need to put the old fuel rails and injectors back on (might as well swap the manifold back). Or you can get a 90-91 ECU....However that can open another can of worms, which you probably don't want to deal with.

 

I swapped a set of 92 balanced and blue printed injectors in my 90, and it ran, but it got horrible mileage and power was not what it used to be.

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Ok....here's how you can tell which plug goes where.

 

Check the color of the wires going to each plug.

 

The numbering scheme should be the same as the piston numbering scheme

 

3 4

1 2

 

front of engine

 

 

For the 92-94 legacies

 

#1 injector

 

Pin 1 = Br (Brown)

Pin 2 = Y (Yellow)

 

#2 injector

 

Pin 1 = Lg (Light Green)

Pin 2 = Y (Yellow)

 

#3 injector

 

Pin 1 = LR (Blue w/ Red stripe)

Pin 2 = Y (Yellow)

 

#4 injector

 

Pin 1 = LB (Blue w/ Black stripe)

Pin 2 = Y (Yellow)

 

 

If you need the 90-91 color scheme, let me know.

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Well, The spark plugs fire in banks. I believe it's both lefts and both rights at the same time. I would expect that if you had the injector wires backwards you would get serious backfiring.

no, 1 & 3, and 2 & 4 fire at the same time. each plug is connected to one end of the secondary coil winding in the DIS module, so the spark comes out one side, across one plug gap, through the block, across teh other one (Relatively easy since it is not firing under compression), and then back into the other side of the coil. This is the reason why this DIS is referred to as "Waste spark" since one spark is "wasted" on an empty cylinder. (As opposed to coil-on-plug which uses a coil for each plug.. Very efficient, but at 90kV+ you do NOT want to come across it!

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my #1 injector plug is brown & yel + red stripe

#3 is yey + red stripe & blue +white stripe

 

can I just put the 93 injector in place of the 90-92 injector or switch just the rails (not the twisting tubing going to the fuel line). The darn junkyard told me it's a 93 motor, it really is a 90-92. But with 65,000 (on the title, I forgot to look at the year.....) I can't complain. I just hope swapping injectors is all I need to do.

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I swapped the injectors and the rails. It idled at 1100 so I turned a screw or 2 on the maf and dropped it down to 800. Like I said, I was lucky to get a very low mileage engine (inside the valve covers it was sparkling clean compared to my 372k motor) So I hope the injector swap will help. Does anyone know why the injectors are so drastically different looking? hopefully my gas mileage will get back to what it was. What other changes are there from a 90-92 to a 93?

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Eek.....there's just way too much stuff going on in this thread. One thing at a time.

 

Hondasucks, how you've described the ignition system is partially correct.

 

It's the 1 & 2 cylinders & 3 & 4 cylinders that fire at the same time. See the little piston numbering diagram in my post.

 

As for how the current flows. It doesn't flow back up into the coil. The front coil is tied directly to the same output for cylinders 1 & 2. Similarly, the output for the rear coil is tied to cylinders 3 & 4. If you had long enough spark plug wires, you could reverse wires 1 & 2.......similarly 3 & 4, and the car would run fine. The power flows through the coil into the plug and then grounds itself through the block and back to the battery.

 

 

John.....so did you swap injectors and fuel rails? It sounds like you did. The 90-91 injectors are different from the 92-94 injectors.

 

Since you have three posts in a row saying what I think you are doing, or did.....can you post the answer's for these questions, for my clarification.

 

What model year is your car?

Which MY injectors and fuel rails are currently installed in your car?

Which MY harness is currently installed in your car?

 

BTW John, the changes took place between the 90-91 MY's and the 92-94 MY's, not 90-92 & 93-94.

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What I have is a 93 with a 90-92 donor motor. I'm using my 93 harness, fuel rails and injectors. Had to lower the idle (1100 when warm in neutral) by turning the stop screws on the MAF. I'm happy I got a 65k motor. I have to drive it for a day or two to see how everything runs now. I have the following passenger side injector plug wires, front: Brown/ yel with red stripe

rear: yel/red & blue/white. I'm assuming the brown set is cyl #1 since the harness to that injector has a white band over the black harness. appreciate all the help. Now it seems like the revs go up a few under on some 2nd to 3rd upshifts on the automatic. Argh

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What I have is a 93 with a 90-92 donor motor.

I hate to keep harping on this, but it is NOT a 90-92. The change occured between the 91 & 92 model years. So it would be a 90-91.

 

 

What color MAF do you have? Black or silver?

 

I was unaware of any screws that could (should) be tweaked on the MAF.

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I lowered the idle bt turning the throttle stop screw, the thing would not idle below 1100 warm. The maf on my 93 is silver,sorry about calling it a 90-92, I stand corrected. I do have worse fuel mileage than I had when everything was 93. I know I'm not supposed to adj. the stop screws on the throttle linkage, but there was no way of lowering the idle speed, the cables weren't tight, no air leaks etc. seems fine now, the cold idle works as does the ac switch. I never ends, now my tranny is slipping on the 2 to 3 upshift. ARGH.....

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Ok,

 

So you have a 1993 Legacy automatic with a silver MAF?

 

You've got the incorrect MAF sensor. All the automatic's had the black MAF sensor.

 

Did it always have the silver MAF?

 

The idle thing.....you shouldn't have turned the screw. By doing that, you're fixing a symptom, not the problem. the MAF sensor thing may be the cause of the idle.

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I thought you are refering to the cast aluminum air flap in between the intakes. That is silver cast aluminum. the thing with the wire in the air flow is plastic (black) is that what you mean? On y 911 and bmw's the maf's are cast aluminum.Sorry if I'm referring to the wrong thing. with the 93 injectors and rails my gas mileage is worse than my all 93 93.

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sorry Josh if I'm confused, it's been a tough week, lost a week's pay finding, getting, installing this engine, having to pull it again because of the rea main seal problem, then after all that was done, swapping the injectors etc. all in my driveway, alone , with a floor jack, and an improvised hoist and a bad back. Did you ever try to get that tranny tube and clip in alone? I'm shot. Now I have a funny tranny slip and terrible gas mileage. Argh......then today my hot water heater floods my basement because of a crack, what's next? your web pages info on error codes etc. have proven priceless in helping me before all this happened.

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Yeah the MAF sensor is right after the air box, that is what I'm talking about.

 

What silver thing are you talking about? The throttle body?

 

Sorry to hear about all the headaches. I'm sort of at a loss to what the issue is, whether it's a tranny issue or engine issue.

 

I know before I swapped trannies, I was getting horrible mileage with my auto. How many miles are on the tranny?

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Yeah, I thought you meant the throttle body. Gas mileage dropped from 28 highway to 22. Tranny was rebulit 9k ago. Now there is a slip in the 2nd. to 3rd. shift under power. Backing off the gas right about shift time results in no tachometer "slip". I figure my computer thinks it's my old engine, old harness, injectors, rail. Can't figure it out. This donor engine does only have 65k on it, I saw the title that was transferred to the junk yard. With my 93 injectors and closed eyes, the seat of the pants opinion is that it feels identical to my original motor. What differences may there be? valves? pistons, I doubt anything significant. What is the difference in the injectors, they don't even look close. Unless the computer has to "learn" this engine, but it shouldn't think it's different anyway.

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