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New Plugs, Wires and Ign. Coil. Air, Oil and Fuel filter where changed a couple months ago. TPS tested with no dead spots. No codes(ODBI). No miss firing that i can hear. I Did a compression test a couple months back and all the cylinders where good and close to each other. I was told if you pull the o2 sensor and the car performs a little better it could show a clogged catalytic. The next thing in line for me is a Fuel pressure test. I`m just kinda lost here looking for other possibilities.
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How does the exhaust gasses look/smell?
Ive never had the pleasure of working on a Subaru and with no check engine data, your on the right track with starting to test for fuel pressure.
You said you replaced the coil already, have you tried stress testing it to make sure your getting good spark?
When was the last time the 02 sensor was replaced? Did you try to disconnect the 02 sensor and see if the vehicle performs a little better (depending on if its a signal wire 02 or a 4 wire o2).
Does that vehicle have a MAF or is it similar to a Speed Density setup? I would definitely be checking for vacuum leaks too.
Keep us posted.
If you have an EGR valve I would check that also, because you could get a hesitation when you start to pull away from a stop.
Without any codes you need to start with the basics but it sounds like you have already covered the tune up items and compression testing, well done. Next it might be time to check the timing to see if that is correct. Also check for any air leaks in the tube that goes from the air cleaner to the engine, if memory serves that engine uses a MAF sensor and if that is the case any leaks in that tube can cause performance issues. Does the engine come up to temp normally? If not you may want to check the cooling system to make sure it’s working properly, if the engine temp is off or not correct it can also cause performance issues.
Good luck and keep us posted.
It does have a MAF sensor. I disconnected the 3 wire o2 and it didnt effect. I didnt throw a code either. It comes up to temp and stays where it should but I will say it runs a little better after reaching temp. Not much but a little. The water pump and thermostat only have a couple thousand miles on them. I replaced the timing belt then and I put it in time (using the hash marks). The idlers and tensioner where in good shape at that point so I didnt replace. The car doesn`t smoke at all and I cant detect any coolant coming out. There is an exhaust leak at the driver side manifold (at the pipe side not the engine) and the muffler fell of 2 weeks ago. I dont know if that could add to it or not. Thanks for all the input fellas. I`m gonna go get dirty.
I wasn’t recommending disconnecting the connector to the MAF but rather you look for any air leaks in the tube that goes form the air filter housing to the engine, any leaks here WILL effect engine performance.
I didn`t disconnect the MAF it was the Oxygen sensor. I checked for vacuum leaks via the propain method to no avail. I haven`t had a chance to check fuel pressure yet but through driving it I have descovered a new symptom when driving the car if I barely press the throttle the car acts, accelerates and pulls hills normally ( for that amount of throttle). It seems the more throttle I give it the more it “bogs” down. Is that a fuel to air ratio problem? Through research it looks like its common for build up on the intake valves on the boxer engines. Common enough they made there own product to clean it. The cars old enough I didnt know if build up could be suspect.
I think your going a bit too far with the valves being carboned up enough to cause a performance loss. I do believe you have a mixture problem but as I said in the last post look for air leaks (you don’t need to do it like looking for a vacuum leak because it wont’ show up that way just physically inspect the hose, remove it if you have to) in the tube that runs from the air filter houseing to the throttle body as any air leaks here can cause the mix to be off because it’s air that was not ‘measurered’ by the MAF sensor. It makes sense that this might be the cause as when you accelerate hard the engine will move making the hole bigger and the problme worse.
One of my instructors pointed out that an exhaust leak downstream of the O2 sensor can still cause the engine to read lean, depending on how far downstream of the 02 sensor it is. If I understood him right, the closer to the sensor, the greater the effect it could have.
When you unplugged the o2 sensor it should have thrown a code.
Are you sure the check engine light bulb is not burnt out?
Do you have a scan tool?
Did you test the fuel pressure?Most obd1 cars do not have self tests nor any monitors to determine faults in the fuel pump and delivery, No code diagnostics on obd1 is hard but usually a fuel issue.
And here is this.
MEASUREMENT OF FUEL PRESSURE
- Release fuel pressure.
- Connect connector to fuel tank.
- Start the engine.
- Measure fuel pressure while disconnecting pressure regulator vacuum hose from collector chamber.
Fuel pressure:
235 – 265 kPa (2.4 – 2.7 kg/sq.cm, 34 – 38 psi)- After connecting pressure regulator vacuum hose, measure fuel pressure.
Fuel pressure:
177 – 206 kPa (1.8 – 2.1 kg/sq.cm, 26 – 30 psi)WARNING: Before removing fuel pressure gauge, release fuel pressure.
NOTE: If out of specification as measured at step 6), check or replace pressure regulator and pressure regulator vacuum hose.
Quoted From Beefy:
One of my instructors pointed out that an exhaust leak downstream of the O2 sensor can still cause the engine to read lean, depending on how far downstream of the 02 sensor it is. If I understood him right, the closer to the sensor, the greater the effect it could have.
I’ve never seen this in the real world but I’ve seen plenty of upstream leaks throw off the readings.
Well I think i found the source. The crank shaft has a keyway groove and a key way. Some how the key way was bent and was wiggling and made the groove bigger wich was allowing the crank shaft to be about a tooth ahead of the cams. So now i have a whole new set of questions. Is there somehow i can fix the groove without having to change the whole crank shaft i.e. welding?
If I am reading this correctly you are saying that the slot in the crank where the woodruff key ( that is what I call them ) sits and keeps the lower gear from turning is now wider then normal ( I am assuming the slot in the lower gear is still the normal width ) this is what I would do… pick up a set of those keyways ( woodruff keys ) I believe harbor freight sells them. they come with a variety of sizes. next , select one that is wide enough to fit tightly in the crank slot. now comes the fun part… since this wider key will most likely not fit in the lower gear slot you will need to grind down the width of the top half of the key to fit the slot in the gear ( basically you will have a key with two different thicknesses ) this will take a lot of patience for sure but it would probably be the cheapest route.
Yea that will throw off the timing in all kinds of ways. It really depends on how much groove is left, if there is too much play you may have to weld or someting like that, You may be able to tighten it in place but it may work loose again. This type of call is difficult to say the least but if you can’t find a way to fix the only way I know is to change out the crank and that’s a lot of work for something like that.
About 6 months ago I ended up getting a new timing gear and a harmonic balancer for about 20 bucks from pull-a-part. Covered the crank and loaded the groove with sleeve retainer. Tightened it down to spec and have been driving it ever since. I can tell its not in perfect time but i have put a couple thousand miles on it and it still performs close to perfect. (Which still kind of surprises me). I have a 95 legacy that was deemed total loss with a 2.2 liter and auto. What is the best way to determine if i could put it in place of the 1.8 and manual. And if It would line up with the mounts and trans?
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