Continuing Problems 88 5KSQ

[urq]

How well do you trust this shop?  Do they have much experience with CIS?  The only electronic means the computer has to influence the mixture is via the OXS Frequency Valve.  IME the mixture screw rarely needs to be touched.  
   
  Have codes been read from the ECU?  What do they indicate?  Have they been cleared after the OXS has been replaced?  Has the fuel control pressure and system pressure been validated against the specs?
   
  I'm thinking that you have a leak into the intake after the airflow sensor plate somewhere ... I stated my prime candidate earlier ... that being the crankcase ventilation system.  Another possibility could be the vapor recovery system.  Has the mechanic blocked these paths into the intake to guarantee that they aren't contributing?  I've never seen this, but I suppose another way to bypass the aitflow sensor is the deceleration valve ... mounted on the airbox ... perhaps it is leaking.  
   
  I agree that the sudden onset of the problem indicates that something has failed, but I wouldn't be so quick to jump to that meaning it has to be something electrical ... 
   
  Steve B
  San Jose, CA (USA)

b1biker at aol.com wrote:
  Fellow listers. driveability issues continue to plague me. A brief update on the current problem. About 10 days ago I installed a new power steering pump and multi-function temp sensor, when I returned the pump core to the parts store it ran fine; on my way home when I tried to accelerate it just fell on it's face and had to be shut off before it would run again. I checked the fuel pump, changed the air filter, and tried disconnecting the O2 sensor. With the sensor unplugged it ran marginally better mut not properly. I put the car into the shop on last Monday; ther found, and replaced?a defective?O2 sensor; now they tell me that it's running way lean and they're having trouble getting the allen screw loose so that they can adjust the mixture. they said that they suspected some sort of electrical problem due to the sudden on-set of the problem but everything seems to be working properly. They have checked for vacuum leaks and can't find any. Now they are going to adjust
 the mixture but are having problems getting the allen bolt loose so thaty can accomplish that task. This is a small independent shop that has a very good reputation, I've been very happy with their work in the past.

I'm at a lose as to where to look. I don't understand how the mechanical adjustments to the MAF sould suddenly get out of whack. I've already spent more than the value of the car in repairs over the past 6 month; which really isn't a problem as I plan on driving it for quite some time. Any advice, hints, BTDT, solutions?will be greatly appreciated.

Thanks in advance,
Gary Meier