running issue w/ low rpms, etc

[movin on]

90 TSI 550/2gmaf
Car has been running rough for while. I installed a FMIC and new coil pack and next time I ran the car, it had problems. Fixed my boost leaks and checked for spark to make sure my newer parts were good.

My A/F gauge always shows I am running very lean when idleing or below 3K rpms. The car sputters and sometimes quits while idleing and when I am below 3K rpms driving, the car chugs terribly. When above that range it runs well and the A/F gauge stays well in the optimal range. The check engine light is not on and when I brought it to a shop they said

"coolant fan runs all the time when key is on. If not hooked direct indicates ect system is out of range. There is a voltage reference of 5.5 volts at switch however grounding out system with small amount of resistance causes engine to stabilize. Need to look at PCM valves and determine what is what. This system calculates fuel to air ratio. Also provides info for oxygen sensor input ot PCM".

They did not get anything else from running a diagnostics because I guess my diagnostics plug is bad. I bought I palm pilot and after plugging it into my car it shows no results for anything.

Evidently this just isn't an issue with cars with turbos. My friends 97 Grand Am GT has the same issue at about 4K rpms.

[cyclone]

umm, sounds like a bunch of crap. Youre problably leaking somewhere after the maf and its sucking in un metered air. But the engine doesnt know that so its telling the injectors to only dispense enough fuel for the amount of air that it thinks the engine is taking in.
Thus lean a/f ratio

[Dizmm]

Yes like said above, it could be a boost leak. I would start with that has 80% of the time thats all the problem is.

[movin on]

The hard sputtering part is taken care of. It was due to my mbc. On the bolt that screwed into the mbc had a nut on it that was set about one third of the way on it. I didn't change it's setting and now I realize because of taking the mbc and to make a long story short. The setting the nut was at completely blocked the airflow, so now I only have the problem of sputtering a little bit while I have been at max boost levels (12.5 lbs) for a second and still sputters while idling.