Chrysler: starting problems: 96 3.5L


Question
I have a 1996 Chrysler Concorde 3.5 w/ 150K on her.  Problem is:  when I start w/ temp around 50 or above it starts great.  After driving for awhile, shutting off engine for 10 minutes or less it starts up again fine.  If longer than maybe 20 minutes it will turn over for exceptional time ( 5 to 10 sec.)  If it is colder than say 40F start times are too long also, very cold is worse.
I have replaced fuel pump, filter, injectors, plugs, wires, air and water sensors on top of engine and intake gaskets.
Battery is also new, old one died.
No codes besides 5 5.
Thank you in advance, I'd like to continue driving this car as it was my Mothers, reminds me of her.

Answer
Hi Charles,
Sorry for the delay in responding. Without fault codes it is difficult to be sure why this is happening. But one of the more common causes is that the exhaust gas recirculation valve is fouled up as far as the valve stem action is concerned. You can spray some WD-40 or similar solvent on the stem where enters the body of the valve and them notice the slot in valve stem into which you can then insert the tip of a screwdriver to move the stem back and forth (against spring action in one direction that tries to close the valve). That may then allow the valve to close tightly when you shut off the engine which will improve the subsequent starting.
The valve is located on the rear of the right cylinder head and is horizontal. There is a vacuum operated round part on the top, and then between that and the valve proper is a flange that partially conceals the valve stem from view. So look behind the flange to find the stem and its slot.
Roland