200 10V stumbles, poor mileage

[Hayes Myers]

Konstantine: When I don't have garge I like to put up a 'tent' so to speak
around the hood... that keeps the wind out nicely :) Still.. rather it be
daylight as you say. it is kkkold

-----Original Message-----
From: quattro-bounces at audifans.com [mailto:quattro-bounces at audifans.com] On
Behalf Of Konstantine Bogach
Sent: Monday, December 21, 2009 4:35 PM
To: David Michael
Cc: Quattro List
Subject: Re: 200 10V stumbles, poor mileage

Dave, thank you very much for such detailed response.
  Can you explain in more details on how to do the measurement in your 
item 2?  Which points to hook O-scope to?
Duty cycle sweep is same as before, maybe a little wider (35-65).
Air meter plate is always a suspect because you can't see it.  Can I 
reach it through air filter box?
Can coil be bad even resistance test is good?
Need to check air cleaner too.   I have no garage and have to wait next 
weekend - I need at least daylight if not warm weather.

Thank you.
Konstanine.

On 12/19/2009 10:50 PM, David Michael wrote:
> Konstantine,
> On and off I have had several bouts of fixing my poorly running 200 
> 10V. Some of the issues it sounds like you are familiar with, but here 
> are some things I learned:
> 1. Air leaks. Double, then triple check. Use Scott M's site as a guide 
> for where to look.  Injector seals, valve cover gasket, rubber "igloo" 
> and intake hose clamps all good places to look. All are easy except 
> for the injector seals..
> 2. I fought a poor drive ability problem for very long time before I 
> found that the Hall Sensor in the distributor was sending false 
> signals. I finally found that when I hooked an O-scope up between the 
> distributor and coil, and found there were random "ghost signals" 
> inter-spaced with the sine wave. New dizzy fixed a world of problems.
> 3. When you set your idle mixture duty cycle, make sure you also set 
> the  idle valve control current with the bypass air screw. It's best 
> if you have two meters - one for the mixture duty cycle and one for 
> the bypass valve current. If you cannot set the idle air valve it to 
> 430MA, look for the reason why......
> How steady is the duty cycle at idle? It should not swing by more than 
> about 30%
> 4. I had a very strange problem where my control pressure regulator 
> was not constant - it would randomly change the control pressure by 
> ~5psi. But that affected the part throttle accelerating, not idle. New 
> WUR fixed that.
> 5. Make sure your air meter flapper plate moves without binding - 
> there is a roller bearing under the fuel distributor plunger, and mine 
> was occasionally sticking.  I fixed it by spraying some  lubricant 
> through the idle mixture setting hole. You have to bend the tip of the 
> lubricant can little red hose at 90 degrees to do this. It would be 
> better to remove the fuel distributor from the AFM but that is a PIA.
> 6. You need to find out if your car is hard to start because there is 
> too much fuel or too little. I did have  a drippy injector once, and 
> it would cause hard starting after 15 minutes - but you could also 
> smell gas. It also had no affect on idle.
> 7. Other things I have done that may or may not have helped: New coil, 
> new plugs, new TDC sensor, new air cleaner
> Good luck
> Dave
> 90 200 qa 240k

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