NorthWet

Before worrying about the complexities, take care of the everyday: New sparkplugs, sparkplug wires, distributor cap and rotor. Also, don't forget the fuel filter.

What you have is, essentially, a dumb valve. You want to vary how long the valve is kept open, not how often you open it. Two methods can be used: Pulse width modulation (PWM), or pulse code modulation (PCM). Pulse code modulation keeps the length of the opening time the same, and varies how often the valve is asked to open; it varies frequency but not the cycle's "on" time. PCM might be used, but varying frequency might cause some problems involving response time/inertia effects; to get a 1-99% variation would require a 100:1 frequency variation. Far easier to vary the "on" time per cycle.

I sort of mentioned the need for a power transistor or relay, without much elaboration. Assuming that the solenoid uses a switched ground, the 555 should be able to drive a Darlington transistor, or you could use either an op-amp IC or a small-signal transistor (eg 2N2222) to drive a 2N3055 power transistor. All are common and cheap parts.

Nerd, eh? I have still got Mims books!!!! FWD is not as fun to drive as RWD or AWD. Hard to do power-induced oversteer with FWD... As another "Oh, BTW...", I drive my 3AT in 4WD quite often on pavement. Since the transfer isn't by gear, it is less likely to bind then a manual tranny would.

Don't you just love DOA parts??? Trust no one. Assume nothing. Glad to hear the problem is resolved.

Certainly... if someone wanted to spend the time to reverse-engineer the coding and the maps. The question really is: Wouldn't it be better to use an up-to-date, forward-engineered ECU? MegaSquirt comes to mind. Or, a direct replacement that fits the original ECU case and connectors. Wouldn't THAT be something?

Sure does... the "Easy-peasey, and Bob's your uncle" is fairly English. Cheap parts, and stuff you can pick up from Radio Shack. Its simple, really... Honest... The only hard part is finding out what the tranny wants (and fooling the TCU if needed).

Gall Dang It!!! yur rite! fer got bout them yeller wires!

PM'd. I forgot to ask for address.

Striped wires are a female-dog to identify/distinguish without adequate, even lighting. And then they will put a red/white and red/grey wire in the same harness, and expect you to tell the difference after 20 years of aging (both the wire and your eyes! ).

The real reason is money. There isn't any in it with the earlier cars. I haven't opened up an EA81's ECU, but the EA82's ECU contains a real microprocessor; a 6502, IIRC, or a 6809 if IIDRC .

I have a little experience with DMMs... like a couple of years of Electronics Tech training... I MIGHT be able to answer your Q's. Mostly, you will be using the DCV (direct current Volts) section and the Ohms/resistance section. Depending on what you are doing, you will probably be checking to see if you are getting voltage to a component (light/whatever), so set it on 20V in the DCV section, ground (typically) the black probe, use the red probe to check for voltage. DMMs are pretty forgiving, so black and red can be interchanged without any worries (voltage might read negative, though). To check a component for continuity, use the ohms section, and pick a setting that kind of matches your expected reading. DO NOT check for Ohms/resistance on a powered circuit, as it is possible to do nasty things to the meter, and the reading may not be valid anyway. (It is possible to do resisitance checks on powered circuits if you know what you are doing.) Pat

99% chance that the governor valve needs a little TLC. (The other 1% is low ATF level.) The governor tells the 3AT when to shift while in "D", using a centrifugally actuated valve that is spun by the pinion shaft. The governor tends to gum up (sliding valve parts), and the driven gear on the governor shaft tends to wear out. (My personal belief is the gear problem is caused by rotational imbalance caused by the valve sticking.) The governor valve can be easily removed and serviced. It is underneath the 3"-ish dome on the passenger side of the tranny, right above the axle shaft. There are instructions on how to do this on USMB, or I can tell you what to do. The main thing is that the sliding surfaces NEED to be deburred and sanded/polished so that they slide like a hot knife through butter. Servicing the governor valve (and changing the ATF!!!) can make a huge difference in how the 3AT works.

Idealized (discounting signal distortions ), it would be a square wave. PWM is fixed frequency, variable "ON" time. The "ON" transitions occur at fixed intervals, but it stays on for a varied lenght of time before transitioning "OFF" again. The basic electronics is very simple: You can either use a dedicated PWM chip, or a chip with a pair of generic timer circuits (556 Dual Timer IC). With the 556, you would set one timer to be an "astable multivibrator" (produces a fixed frequency output signal) and feed that into the trigger of the second timer circuit configured as "one-shot" (that produces the "on" signal). Circuit requires a couple capacitors and resistors to set the timing, and you can use a potentiometer to set the one-shot's "on" time (the duty cycle). The output of this can be fed to a power transistor (if DCC is switched-ground), or a relay. Easy-peasey, and Bob's your uncle. (And, at the risk of being argumentative, HDDs use rotary voice coils for head positioning. Steppers haven't been in common use in 15 years.)

Nipper is both correct and not correct regarding solenoids. They generally are used in a simple on/off mode. But they can be used in a varied-voltage mode... just with little guarantee of how "on" or "off" they will be at any given voltage. Audio speakers are an example of a solenoid-like device that is controlled by varied-voltage, as is the positioning coil on a hard disk drive. If the "duty-cycle" signal that you send to a solenoid has a short enough interval between signal transitions (relative to the solenoid's inertia/reaction time) then the solenoid will essentially "see" a varied voltage anyway. The electronics to send a "duty-cycle" signal (technically, Pulse Width Modulation, aka PWM) is relatively simple and inexpensive. The parts would at most cost a few dollars (say $5-10), with the main IC costing about $.50. If somone could "o-scope" the duty signal to find out its frequency and the bounds of the duty cycle, or if this information is provided in the FSM, it would be pretty easy to whip something up. Also, it would be needed to know if the Duty C solenoid has 1-wire (switched power, ground to case), or 2-wire (constant power, ground switched by TCU). **Edit - BTW, I believe that a similar method could be used to make 3ATs into FT4WD/AWD trannies, since their transfer clutches operating on similar principal, though maybe not as robustly designed. At the very least, it should be easy to have a 51/49-ish split by occasionally sending a pulse to the solenoid to release the transfer clutch pack. - end edit**

Touring wagons have a different roofline than normal Subaru wagons, with a hump that starts a little bit behind the windshield (IIRC)... sort of like they welded another wagon roof on top of the regular one, giving a couple inch rise in the roofline.

A thought: Get a viscosity cup (I know you can get one from paint stores, used for telling if paint has been thinned enough to be sprayed) if you don't already have one, and "measure" the viscosity of the original shock fluid, preferably at room and "hot" temps, and then do the same with some known oil viscosity. This should give you a baseline for viscosity changes.

My suggestion: Put in a new set of spark plugs, warm it up to normal operating temp, run it on the skidpad until the smokescreen and/or power cut has occurred for a few seconds (or as long as you can stand it), cut the ignition and pull the spark plugs out and take a look at them. See if any particular plug or sets of plugs are sooted. This should tell you what in general is actually happening. My vote goes for a loose/bad wire/connection... my first thought was spark plug wires. Spark plug wires can go bad at any age, even OEM; and one year old is not really the same as new. Directed at the novices (the ones with far less than 7k+ postings): When your engine isn't running right make sure that the ignition is first rate, with new parts, especially spark plugs. Make sure the ignition timing is set properly. The ignition is the foundation for all of the rest of the engine's tuning, so get it right before you go messing around with carburetor, FI, cams, whatever.

What makes you believe that the engine is worn out? Many symptoms have other causes...

Life happens. Don't dwell on what might have been, or try to second-guess Life. Just be truly happy that everyone walked away, be thankful that your Subaru held up as well as it did... and get to a doctor to have your self checked. Soft tissue strains/injuries can take a day or two to show up. Best wishes. Pat

I would agree with Hush777 that it would be better to stay with the MPFI. Regarding the mechanic that said that he could do it, I believe that he was just going to replace the throttle body with a carburetor, rather than removing the entire intake system and replacing it with a carbureted system. The oxygen sensor is needed for the MPFI to operate properly; it is possible that the previous owner replaced the front portion of the exhaust system with a part from a vehicle that did not use an oxygen sensor. The oxygen sensor should be mounted where the two pipes from the engine exhaust ports join beneath the engine, very near to the right side (as viewed from the driver's seat) axle's inner joint (rubber boot).

The air charge does not get hot enough to "detonate"... virtually all early turbos were carb'd draw-throughs. The problem is that if the engine "backfires" through the intake system you have that much more fuel/air to burn. Also, the turbo is very likely to get damaged, as in overpressuring the seals or stalling the compressor.

Please note that the vacuum will go way down with throttle opening (duh!)... and with altitude. You may not be able to get a deep enough vacuum at 3/4 throttle. Perhaps a more important question is how much airflow the gyro needs; too great of a CFM demand and your engine won't idle... at least not at a low RPM.

Several importers around Lynnwood. Japanese Engines, Inc. is one that I have used and been satisfied with.

You really need to figure out your ignition timing before you go messing around with cams and such. There are various means to find TDC, and everything else is just math and measuring for the marks.