just an FYI - I had my engine apparently lean out last year, requiring a rebuild. It appears that my original, 21 yr.-old fuel pressure regulator is faulty, fuel pressure is 8lbs or so down from what it should be, and the probable cause of leaning out. I would highly recommend doing a fuel pressure test at this point in any E30's life (particularly if you track it), and/or are above 150k miles, even more so if 200k or more. I think the only indicator you might get of low fuel pressure would be a check engine light. Perhaps Paul can offer up some comment on which conditions trigger check engine lights. Not sure if it's triggered by both low and high out-of-range readings. I didn't see any running problems w/ the pressure being a bit low, but it is certainly enough to be dangerously lean @ full-throttle, high-rpm running. If you do a pressure test yourself, unless you do something to de-pressurize the fuel lines, be prepared for fuel to spray directly at you when you detach the fuel line (keep a fire extinguisher at hand, wrap the junction w/ a rag or something, and watch your eyes). Make sure you use high pressure fuel-injection hose for T-ing in gauge.