Chrysler Repair: 95 3.5L cold starting problem: no codes, side exhaust manifold, coolant temp

Question
Hello Roland. I have a 1995 Chrysler intrepid(Canadian)with/ 3.5l v6. I have checked the trouble codes using the turn key method and only code 55 is recorded. The car will only start in the morning if it is plugged in over night. It will start up right away and runs great all day,but over night it has to be plugged in too start? If I don't have it plugged in it will turn over like mad and floods itself and wont start. If I then plug it in and let it sit for a while it will start and run fine. any ideas?

Answer
Hi Calvin,
You might want to check the resistance of the coolant temp sensor next to the thermostat housing to see if it is reading in the range of 7-14,000 ohm when cold. That as well as the charge air temp sensor on the rear of the intake manifold are the most likely items to affect mixture for cold start up. Were either of these reading low that would cause an incorrect (too lean) mixture.
The other item would be the egr valve, under the throttle body which you could check to see if it might be stuck slightly ajar. It can do that without setting a code. It is located on the rear end of the cylinder head, near the right rear corner of the engine. It has a vacuum hose attached to its top. The exhaust gas is supplied to it by a small diameter exhaust pipe that branches off of the right side exhaust manifold (about the middle of that manifold) and runs around to the rear of the engine where it goes into the egr valve. So look for that small pipe and follow it back to where you will find the valve. The stem of the valve has a slot into which you can insert the tip of a screwdriver and thus move it back and forth against spring-action in one direction that tries to shut it. If it doesn't close to a dead stop by the spring, then squirt some WD-40 on the stem where it enters the valve to free-up the action.
It also may be useful to clean the throat and both sides of the throttle plate and the air by-pass passageway at the throttle body.
Roland