1990 20V no start when cold

[Cody Forbes]

Flywheel sensors can be bad and pass tests. Swap both from parts car or monitor them with an oscilloscope. Also don't get the plugs backwards, not sure if that's possible on your car but on 5000's, 944's and 911's I've fixed them many times when somebody confused the RPM and TDC sensor plugs. 

-Cody
(Sent from my phone, if a word doesn't fit blame Siri)

On Mar 25, 2012, at 7:01 PM, "Mark Rutherford" <mark.rutherford at emerytelcom.net> wrote:

> I am looking for ideas on how to fix a no start condition on my 1990 90 20V
> 7A.  
> 
> 
> 
> Here is a chronological history of work done so far.
> 
> 
> 
> Initially the car would not start when cold < 40F.  Would start with a shot
> of ether, but would not rev well unless the throttle is eased into.  I have
> replaced and checked everything I can think of( there is a list below of
> items I have tried).  With the manifold removed and the fuel supply
> connected I turned over the engine and noticed that no fuel in admitted
> during starting.  Taking a injector to ground triggers the injector, but
> they are not triggered from the ECU.  This does not seem right.  Shouldn't a
> small amount of fuel be admitted during cranking?  Any experience, or
> suggestions out there.
> 
> 
> 
> Pulled mass air sensor high voltage code.  Replaced code went away problem
> stayed.
> 
> 
> 
> Pulled coolant temp sensor code, changed it, original was still in spec,
> code stayed, problem stayed.
> 
> Checked wiring OK
> 
> Wired sensor directly into ECU still have code on 2 different ECU's.
> 
> 
> 
> Found throttle position sensor on bottom of throttle body had fallen off and
> was cooked.  Replaced, still have problem.
> 
> 
> 
> Replaced the following from a parts car that will start at any temperature
> and runs fine.
> 
> 
> 
> Mass air flow, idle stabilizer, throttle body and sensors, distributor,
> computer and coil.  Still have problem.
> 
> 
> 
> Checked fuel pressure, 85 PSI, a little high, replaced pressure regulator,
> holds pressure and meets specs from Bentley.
> 
> 
> 
> Checked fuel delivery volume, meets Bentley specs.
> 
> 
> 
> Replaced fuel injectors and rail from parts car, resistor pack, both the
> original and parts car meet specs for resistance.
> 
> 
> 
> Check all wiring from plug A on the computer to source, replaced fuel pump
> relay, RPM and timing sensor, all originals passed tests from Bentley.
> 
> 
> 
> Placed all parts back on the parts car.  Parts car starts and runs well.
> 
> 
> 
> Moved parts back to problem child.  
> 
> 
> 
> Checked pin in the fly wheel , found one about 15 degrees BTDC. 
> 
> 
> 
> Looked to ensure distributor, cam, and crank are all in sync.  No problems..
> Condition remains.
> 
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