This is kind of a weird one for me. I haven't come across an issue like this before, so I'm not really sure where to even begin diagnostics at. I drive a 1997 Legacy GT with a 5 Speed (EJ25D NA engine) My car starts and drives great. No issues except once in awhile. While I'm coasting in 4th or 5th gear, the car will bogg down sometimes. It only happens when I feather the gas to maintain speed. It never happens past about 15% throttle. It almost feels like I'm trying to pull a 50,000lbs trailer up a hill. To correct the problem, I can push the gas in a little more and about 2 seconds later it will kick back into normal operation after throwing me back in my seat a little bit....or I can push in the clutch, rev it up a little bit, and let off the clutch again. At first I was thinking something along the lines of the rear diff or the transmission having problems (low fluid level or something like that), but I've checked as much as I can check and it seems OK. Clutch is new (about 10k miles installed myself). I've recently done a tune up (less then 20K miles) using a Duralast wireset and Denso Double Platinum plugs. I've as well checked for vacuum leaks (via smoke machine) and didn't find anything. Throttle body is sparkling clean....blah blah blah. New fuel filter as well. My check engine light isn't on, and there isn't any codes. Part of me thinks it may be the fuel pump, but with intermittent problems only in certain gears seems kind of strange to be a fuel pump...especially with no problems starting the car. Has anyone ever come across this before? What possible repairs might I be looking at?
that almost sounds like the typical Subaru hesitation. Sometimes regrounding the motor will fix that.
I've done the grounding mod and cleaned the iac and maf. here is a video. start watching it at 1:50. about 1:55 you will hear the engine bog down. then about a second later you will see the camera shake from it kicking back in. This isn't normal. I've never seen any car do this. http://www.youtube.com/watch?v=9DzGjdMYYV8
I had something similar to that once..the wires on the MAF were cut from moving around so often and one of them actually completely dislodged itself from the rest of the sensor. Replaced the wires going into the MAF sensor and it solved the problem.
it's usually something stupid simple, get another pair of eyes on it to double check your work. I'm betting a plug wire or faulty connection
its more or less random. it will happen uphill, downhill, and on level ground.....engine cold or warm........warm or cold outside... The only trigger seems to be that it only does it in 4th or 5th gear when I'm feathering the gas to maintain speed. It does it anywhere between 45 - 60mph
well sometime within the next few days I'll be swapping over the coil pack and plug wires with known good ones off another 97 Legacy GT. If that doesn't get anywhere, I'm going to start digging into the wiring harness. Talking with b reel made me realize a few things. Thanks for the help man I'll keep you posted on what happens. BTW Matt, you have the coolest avatar I have ever seen haha