alpop

The outward appearance of boots and such is fine. Haven't driven it enough to know about damp mornings. However it didn't do it when I test drove it in December, then when I came back to pick it up a few days later he had just power washed the engine - It was all wet in there, then It did it bad all 85 miles home.

Hmm, I'll check the resistance on them, I think I read they should be all pretty similar 8000 - 16000 ohms, if greater than 20k replace. Sound right?

Replaced the cracked knock sensor with a $15 Aisin one (Amazon) and took it out. Drove 3 miles to town for a meeting and it ran flawlessly, drove the three miles back and it ran flawlessly, then I thought I'd take it out on the nearby country road just to make sure - and it started acting out again. No CEL yet. I had disconnected both battery terminals while replacing the Knock sensor, as I did for the coolant temp sensor, and both times it ran great for a little while afterwards - then Hmmmm- Anyways on to the TPS, after all I did have a TPS code a few weeks ago.

Ok great pic, thanks! Yes, I see the TPS holes are slotted for adjustment, I hadn't noticed previously. Hopefully I won't have to fool with it, I just pulled out the knock sensor and it has several cracks in it, vertical and horizontal. I'll look around locally here for a new one at a reasonable price tomorrow.

ok I get the explanation on the TPS. However, I don't see how to do the back probing with a paper clip (when its all plugged in) because there is absolutely no room to shove the clip in there and I'm afraid you would ruin something if you tried. Are they really adjustable on the "99? I thought that was on earlier models and mine doesn't appear to have any play in the mounting to turn it. I'll check the knock sensor first. Al

I will check out the knock sensor tomorrow. looks like $50-$60. In terms of checking the voltage of TPS with ignition on and slowly opening throttle. I've seen the descriptions of back probing the wires into the plug (with paper clips?), but there sure wasn't any room for this when I looked at my connector. I guess you could do this by probing the actual TPS pins and looking at resistance, but I don't know what values are expected.

yeah I heard those knock sensors crack pretty commonly, Forgot to say I already put in new plugs, air filter, PCV valve.

Thanks for all the responses! I have had those connectors apart and looked closely at them, couldn't see anything problematic. Needed to unplug them to replace that coolant temperature sensor. Good call on the engine cooling fans and cabin defrost setting - I just checked (ignition on only) and it only does it when set on defrost so that makes sense. I'm used to vehicles with engine fans and fan clutches, so had no idea. So when it did this when the engine was running,and the cooling fans would cycle on and idle would up to 1500 at same time this is probably the same explanation - idle up with defrost and AC on, though 1500 does seem sort of high. So that leaves two problems, inconsistent idle which could very well be the IAC valve (I understand it can be cleaned), and terrible acceleration under 2500 rpm. The idle is not that big a deal so I will concentrate on the acceleration issue at this time. This helps me to feel that it is probably not the ECU unless its related to this TSB about knock sensor and ECU.. So with poor acceleration probably either the knock sensor or the TPS. I did check the reference voltage to the TPS and it is about 5 volts (ignition on) as expected, there is another test to look at resistance of the TPS as you slowly open the throttle which I could try to do. The darn things look really expensive, cheapest was $120 at Amazon, on up to $250 or so. So why does Subaru run coolant through these components? I did a simple test with the knock sensor to make sure the sending wire/terminal was not grounded and it was not. Might try physically removing it, leaving it plugged in, isolate it in some padding, grounding it and see if this makes a difference in performance, if so then it is either the knock sensor or the way the ECU reacts to the knock sensor. Make sense? which should I fool with first? I guess since I did have a TPS code probably that. thanks, Al

Newbie here. Picked up this 1999 Legacy L wagon with 2.2 engine and automatic transmission for my HS daughter to have AWD in the winter. I noticed a little heasitation at sale but glossed over it. Exterior and interior beautiful cond., good price. The below problems are intermittent, sometimes runs great. PO was a backyard mechanic who dropped the new (used) engine in the car which the 2x PO had burned up the old one. New engine is a phase II 2.2 from a '99, 5" spark plug tubes, all wiring harness plugs fit and are fully plugged in. The main problem is very poor acceleration below 2500 rpm, then at 2500 rpm its like you flip a switch and it takes off like a rocket. Typically you'll be trying to get it going and its lugging in that particular gear, then hits 2500 rpm and takes off in that gear briefly before shifting to the next gear and lugging below 2500, then takes off , then shifts, etc. Does it with manual shifting also. Other aberrations are at times when I turn on the cabin heating fan the engine cooling fans will turn on at the same time, and then turn off when I turn off the cabin fan. At times the idle will go up and down from 700 to 1500 and the cooling fans will go on and off in concert. Can happen even with the engine stone cold. At times the idle will be all over the place. Done a few simple things like cleaning grounding points in engine compartment, installed new grounding system, checked spark plugs (new), checked transmission oil (looks excellent and level right), latest thing was replaced the coolant temperature sensor on the advice of PO and that made no difference. CEL off and on, codes include TPS and IAC valve low voltage in circuits. Current ideas include: 1. replacing ignition wires 2. isolating knock sensor with padding (and ground) see if performance improves 3. TPS? 4. IAC valve? wouldn't explain acceleration issues 5. ECU? These Subaru sensors seem pretty darn expensive. I saw something about a TSB for this year and engine, where the knock sensor signal is mis-interpreted by the ecu and it retards the timing 10 degrees or something, fix was to get a completely different ecu. Haven't actually found the TSB. Ideas?