dp213 Posted July 19, 2017 Share Posted July 19, 2017 I just got a 99 impreza sport wagon 2.2 5 speed 175k. The previous owner said it had a lack of power. After trailering it home, I drove it around for about 30 minuy es with no problem. I decided to do timing and reseal. Got done drove great for about an hour then started having problems they were talking about. It definitely has a lack of power at times. If I try, I can find the sweet spot with the gas pedal and it does great. A little to much or not enough and it loses power. If I floor it, it will kick in and run fine. It does this in all gears. I put a new fuel filter on it, because it was easy, but no change. Any help would be great. Thanks Dp Link to comment Share on other sites More sharing options...
lmdew Posted July 19, 2017 Share Posted July 19, 2017 Are there any CEL Codes? The mass airflow sensor could be going out. Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted July 20, 2017 Share Posted July 20, 2017 scan for codes as said possible exhaust blockage or knock sensor - but any codes will be important Link to comment Share on other sites More sharing options...
dp213 Posted July 20, 2017 Author Share Posted July 20, 2017 No codes no cel. I did scan it and check live data and noticed my tps is flat lined at 0 while idling. I loosened it to adjust it and no change at all. Still 0. I am going to put a new one in tomorrow. I have noticed now that this lack of power only happens after driving for about 45 minutes. For the first 30-45 minutes it runs perfect. ????? Link to comment Share on other sites More sharing options...
dp213 Posted July 21, 2017 Author Share Posted July 21, 2017 So I put a new tps in it and same thing. Runs fine for a while then goes bad. Tps is now at zero and non responsive Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted July 21, 2017 Share Posted July 21, 2017 some sensors require a 5v reference I think - maybe something is killing that line after it gets hot? Link to comment Share on other sites More sharing options...
dp213 Posted July 28, 2017 Author Share Posted July 28, 2017 Well, after taking it to a mechanic buddy. I found out the motor has internal problems. When rpms go up there is a faint knocking sound. The knock sensor is picking it up and retarding the timing. I am pulling the motor to replace it. At least I had another motor already sitting in my shop. Link to comment Share on other sites More sharing options...
AdventureSubaru Posted July 29, 2017 Share Posted July 29, 2017 (edited) i'd go with a new knock sensor first. They fail ALL THE TIME These motors are consistently tappy sounding. No need getting scared off by what could be normal chatter of a subaru. Edited July 29, 2017 by AdventureSubaru 1 Link to comment Share on other sites More sharing options...
dp213 Posted July 31, 2017 Author Share Posted July 31, 2017 I did a new one knock sensor and it still did the same thing. Run fine for a while, then power loss. Swapped motor and all is well now. I used the intake (with knock sensor) from the old motor. Runs great and no power loss. Link to comment Share on other sites More sharing options...
dp213 Posted August 2, 2017 Author Share Posted August 2, 2017 Today it started doing the same thing again. Apparently I hadn't driven it long enough since the motor swap. Now I'm stumped. New knock sensor, fuel filter and pump, plugs and wires. Not sure what to think now. Maybe ecu? Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted August 2, 2017 Share Posted August 2, 2017 (edited) maybe some of the media in the cat conv is loose and blocking exhaust? vacuum gauge testing might be good - might spot a sticking valve too??? sure the feeling of power loss isn't a sticking brake caliper or some other dirveline issue? Edited August 2, 2017 by 1 Lucky Texan Link to comment Share on other sites More sharing options...
AdventureSubaru Posted August 2, 2017 Share Posted August 2, 2017 (edited) I'm still suggesting mass air flow sensor. They are known for causing the engine to periodically become gutless and even stall out without throwing a code. Intermittent fuel pump would be number 2 on my list. I chased one all over the place trying to find why it bogged down on hills until I could actually hear the pump whirring, then I knew for sure. They are cheap and easy to grab from a junkyard. I think $10 put me back on the road that time. At least you know that first motor is good. Now you've got a spare. Edited August 2, 2017 by AdventureSubaru 1 Link to comment Share on other sites More sharing options...
dp213 Posted August 3, 2017 Author Share Posted August 3, 2017 Fuel pump is new. Mas is cleaned, not new. Guess I could swap it out. Shitty part is, car ran great for a couple days and I just finished moving to a new place with no shop, so I scrapped the other motor Link to comment Share on other sites More sharing options...
idosubaru Posted August 5, 2017 Share Posted August 5, 2017 1. Swap the MAF. Www.car-part.com or post in parts wanted here. 2. When it does it again pull the fuel hose and crank. If it flows like a hose the pump is fine. If it trickles out you found your issue. Link to comment Share on other sites More sharing options...
dp213 Posted August 13, 2017 Author Share Posted August 13, 2017 Update. Fuel pump flows great, maf swapped, still same problem. I had a scanner hooked to it today and was watching live data while driving around. I (think) all looked well, but I no tires 1 thing odd. The line labeled fuel sys1 was bouncing back and forth between clsd and open1. Does anyo me know if that is normal or should it stay one way or the other. It would change all the time, car was comepletly warm and it would do it while I was giving it gas or not. Link to comment Share on other sites More sharing options...
dp213 Posted August 13, 2017 Author Share Posted August 13, 2017 And also the line labeled abslt tps was at 0.0 again at idle. I had it set at .45 at idle to begin with. Link to comment Share on other sites More sharing options...
dp213 Posted August 14, 2017 Author Share Posted August 14, 2017 ? Link to comment Share on other sites More sharing options...
dp213 Posted August 14, 2017 Author Share Posted August 14, 2017 Something is making the tps reset to 0.00 after driving for a bit. I have changed the tps and still does it Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted August 14, 2017 Share Posted August 14, 2017 any chance of wiring damage from rodents or pinched by some work that was done? Link to comment Share on other sites More sharing options...
dp213 Posted August 14, 2017 Author Share Posted August 14, 2017 I am about to pull the dash. Everything in the engine bay looks good. If I don't find bad wires in the dash then I am ordering the ecm Link to comment Share on other sites More sharing options...
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