200 10V stumbles, poor mileage

[Konstantine Bogach]

Stumbling is solved.  It was TPS (infamous soldering inside the switch). 
   I had two such switches before but I could not recall this symptom.  
I did not check the signal on O2 sensor and did not drive enough to see 
the mileage.  By the way, yesterday O2 sensor was pegged to 0.1-0.2 V.  
But when I tried to adjust the mixture to the rich end, nothing changed 
until engine started to shake.
  Car drives just super.  It is getting new shoes this week.
As far as CSV goes,  I measured voltage on the connector when engine was 
on.  I did not check wiring for hacking  yet.  I disconnected it a few 
days ago.  That did not change anything  but I keep it disconnected 
until I check the wiring.

Thank you very much to everyone for help.   I would not be able to keep 
this car without your help.

Konstantine.

On 01/02/2010 11:51 PM, Ben Swann wrote:
>
> Steve, Konstantine,
>
> The Cold Start valve only pulses in order to get the engine started, 
> and therefore is only activated during cranking and possibly initial 
> startup.  The CSV only pulses about 10 times when engine is stone 
> cold.  Any more and the engine would flood quickly.
>
> The CSV does not activate during WOT and not only is not the type of 
> injector that would be used for additional  fueling, but is in a bad 
> location for adding fuel for performance - too much fuel would end up 
> at cyl. #4 & 5 and #1 & 2 would be too lean.  So don't consider this 
> location for supplementary injector, which should be placed before the 
> throttle body or directly in muli-port configuration.
>
> If faulty CSV operation is suspected (I'm scepticatal) then get engine 
> started and disconnect the connector to it.  Unless it actually is 
> leaking, then CSV would be out of the picture for diagnosis.  I bet 
> there is no difference and problem lies elsewhere.  If CSV leaking is 
> suspected, then unbolt it from the manifold and run fuel pump.  You 
> would see it dripping fuel.
>
> Unless there is visual evidence of a hack job, or melted wiring inside 
> the harness, I'd be looking for the problem elsewhere.
>
> The sypmtoms as described are that of massive air leak that opens up 
> under load.
>
> Also, bad temp sendor or O2 sensor would cause problems as described 
> as well as other culprits.
>
> Once again,  there should not be a path to ground at the CSV connector 
> during normal engine operation.  If engine is not running, but 
> ignition is on, I surmise that the loop would be closed and perhaps 
> that is why it is suspect.  Check while engine is running - should be 
> no continuity to ground.
>
> Ben
>
>