Ford Repair: Sporadic starting problem with 4.6L V8 T-Bird, air induction system, mass air flow sensor

Question
Thank you for your assistance, Dave.  I will try it to see if it solves the problem.  But, since
the MAF sensor is kind of an expensive part, I was hoping you might be able to give some
insight to maybe eliminate another possibility a buddy of mine mentioned.

Do you think that we can rule out the possibility that a faulty fuel vapor valve might
be part of the problem?  Again, I really appreciate your help!

Richard

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Followup To
Question -
I have a 1996 4.6L Thunderbird with a sporadic starting
problem.
Occassionally, when starting the engine in the morning, the
starter will turn normally, the engine will crank, and all of the
normal dashboard lights will come on, but the engine won't
start.

The symptoms seem to indicate that either no fuel is getting to
the engine or there is no spark. No engine diagnostic codes are
stored.

I have had the idle air control valve replaced and also had the
injectors and air induction system cleaned.

Sometimes after failing to start, it would start when I retried it
30 minutes later. Other times, it would not start for several days
in succession.
Any suggestions would be greatly appreciated.
Answer -
Well, my first guess would have been the Idle Air Control Valve.  The next thing that I would
suspect is a bad Mass Air Flow Sensor, it is another common repair for this vehicle.  There isn't a
good way of testing a MAF Sensor.  Most of the time, you can monitor the voltages at a "known
bad" MAF Sensor and they will all be within the acceptable range.  For diagnostic purposes, you
could try unplugging the MAF Sensor while the engine is acting up. I believe this engine uses a
Throttle Position Sensor for redundant sensor inputs.  At our Dealer we would try swapping out
the sensor with a "known good" one for testing.  Some people would suggest disassembling the
MAF Sensor and carefully cleaning the sensing wires inside with an Air Intake Cleaner.  This
repair is not recommended by Ford, and is generally a temporary fix.  I wouldn't expect to see
any DTC's with this type of concern, and cleaning the Fuel Injectors and Air Induction System was
a good thing, even if it didn't fix your problem.  Fuel Pumps are not common repairs for this
vehicle, but I would check to make sure that you have fuel pressure before replacing anything
else.

I hope this helps,
Dave

Answer
I have not heard of a Canister Purge Valve or any other EVAP System part causing a "crank/no-start" concern, and if it malfunctioned it would trigger a DTC.

I would first try the procedures I listed before replacing the MAF Sensor or any other parts.

I hope this helps,
Dave