88 Merc Sable - 3.0 V.6 EFI - Engine is flooding

I have an 88 Merc Sable with a 3.0L V6 EFI that is flooding.
What has alerted me to this condition is that it wouldn't start for my wife one day. I checked all the normal things and everything seemded to
be in order. I had put new plugs, wires, cap and rotor on it about 2000 miles previous to the no start condition. I had spark, fuel, compresson and the timing was correct.
I took it to my local mechanic who also cound not get it to start until he drilled the catalytic converter to check for blockage. The car eventually started and ran fine. Welding the holes back up the car would start and run for a few minutes then died due to the plugged cat. I had him redrill the holes for so I can drive it down to have the cat replaced.
BUT.... before replacing the cat I want to solve the flooding problem that probably plugged it up to start with.
The car still will not start normally when cold. It seems to be flooded. After the first start the engine will start normally, cold or hot, without any problems. To initially get it started I have to hold the throttle wide open to dry it out which can take several minutes of cranking (with breaks not to overheat the starter.) The only engine code was for the TPS which would not cause the engine to flood but I have replaced it anyway.
QUESTION... Will a plugged cat cause this EFI engine to flood after it has been shut off and goes cold? (I don't believe so) The only thing I can think of that would cause the engine to flood after being shut off is leaking injectors (although it should also flood when hot and left to set but it starts right away!)
Thanks in advance for your help....
Jim
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Have you tried spraying the living shit out of the throttle body with throttle body cleaner while reving the engine up to keep it running. Try that the next time it is running and hot. Maybe your spark plugs are not gapped properly. How is your fuel filter ?

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What is the fuel pressure?

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Check the Idle Air Control Motor, (IAC motor).

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Finally found the problem with this car - the coil was weak. Sounds strange but that is where the problem was......
Had my mechanic remove the plugged cat so there was no back pressure and still the car would flood horribly on the first start of the day. After that it would start normally. Timing was checked again and was dead on. I replaced the coil on a whim and the care fired right up the next morning and has been going strong since. The cat has been replaced now and everything is back to mormal.
Jim
James Pearson wrote:

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James Pearson opined in

Now THAT is weird.
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