Odd FI problem on 90 Legacy

Check the obvious first: plugs, wires etc. Sturtter is more evident at low speed since less fuel/air is going into the engine. Check for an air leak, this really throws off low speeed running, with often little effect on higher speed running. Also add some injector cleaner and moisture absorber (dry gas) before getting it looked at. Ed B

If that doesn't work try unplugging your O2 sensor, it'll run rich (like when the engine is cold) if the shudder stops then it may be fuel mixture problems. Another problem could be hot carbon deposits in your cyclinder igniting the fuel before the spark plugs do. This can be relieved somewhat by using higher octane fuel.(this won't fix the problem of carbon build up but may prevent the carbon igniting the higher octane fuel).

Mike

I found 2 air hoses off but strangely enough, it didn't help. It's probably time for spark plugs so I bought a set and if I can get some help, I'll run a compression test at the same time. It doesn't make and strange noises but now feels like it's running on 3 cylinders at low rpm (no power and it shakes.)

I already ran 2 bottles of injector cleaner (and at least a full tank of gas) through it with no success. I'm not supposed to work on cars where I live but I manage to sneak in a little here and there. For any major work I have to take it to a friend place then wait for it to cool so I can before I can get anything done.

Tony

I'll look for the O2 sensor and try that. This car has 172k miles on it and I'm the second owner. Who knows if the O2 sensor has ever been replaced.

Tony

check the coil

A note of caution on checking the coil

I have 2 '90 Legacy's. Last summer, one was running, one was not, so I checked the coil in the not running one. By the 'specs' in my Chiltons book, the coil was bad. So I took the coil out of the running one just to verify if this was it before plunking down $100+. It did not help. Not only did both coils not pass the resistance test, they both ran fine in the running car. The problem turned out to be something else. Beware of Chiltons ! The edition I have for '90 Legacy is full of inaccuracies.

Thanx, but I had a run in with Chilton 20+ years ago on a VW Dasher. I had just replaced the transmission and filled it with gear oil. Later I read in the manual that I had only put in half as much gear oil as it was supposed to have. It cost me $10 to have it put on a rack an to be told the gear oil level was fine. Normally I would have done it myself but the monsoon season had started here in the Pacific Northwet and I didn't want to crawl under it in the rain. I bought a factory manual and burnt the Chilton.

The problem sounds fuel related. I know this sounds dumb but as a former motorcycle mechanic I have a feeling for these things but I don't know squat about fuel injection. I guess it's about time I learnt. I'm going to check the resistance on all the fuel injectors when I get to it next. I've been riding my bike so the my Subie has been a low priority.

Tony