Chrysler Repair: 2003 Chrysler minivan starts then dies

Question
QUESTION: I have a 2003 Chrysler T&C minivan with a 3.3L with 150K miles. In June, the engine computer crapped out and had to be replaced -- then engine wouldn't start after coming out of a restaurant, and I had to have it towed. The technician told me when I came to pick it up that I shouldn't be surprised if my car does unusual things such as RPMs changing or shifting gears in an unusual manner, as the new computer has to learn how I drive.  It sounded reasonable to me.  Everything worked great for a few weeks, but then one day, when I started the engine, it would start right up but then die after a second or two.  I would have to do this two or three times before it would finally stay running.  When the engine runs, it never runs roughly.  I might go another 2 or 3 weeks before it would do this again.  Eventually, I would get it started, and everything would be fine.  There was no rhyme or reason to when this would occur, and I simply chalked it up to the new computer.  Over the past 3 weeks or so, this problem has become more frequent.  Then 2 days ago, when returning home on a long trip, the engine died while cruising down the interstate.  I at first thought that maybe I had broken a serpentine belt, as I had had that happen years ago in another car, and the sensation was almost identical.  But when I drifted over to the shoulder and tried starting it, it started right up.  It happened again about 10 miles down the road, and I put it in neutral while coasting and got it to start.  The I continued another 250 miles home with no other problems.  Since being home, I have had it do the thing where it starts then dies, but that's it.  I searched your questions and found one here: http://en.allexperts.com/q/Chrysler-Repair-807/97-T-C-starts.htm that almost exactly describes the start-then-die issue.  I did the check for any engine codes recommended by Roland, and no codes (flashes) come up.  I only get a "done" on the odometer.  Any ideas?  Thanks so much.  Joe

ANSWER: Hi Joe,
Without a code there are not too many other possible reasons for stalling or refusing to start. It might be something flaky in the electrical part of the ignition system, or it could be a mixture problem that is not well-monitored by the computer. The mixture is what I would check first:
My immediate suspicion is that your egr valve is sticking slightly ajar which will cause the engine to falter when running/be hard to start/stop at idle speed after slowing down. The valve is located near the throttle body air intake at the end of the engine, mounted in pipe that recirculates exhaust gas from the rear cylider bank exhaust pipe back around to the intake manifold. The exhaust gases have some fumes that can plate out a crud on the valve stem and thus keep it from closing tight when you are at idle. That makes for a too lean mixture so the engine stalls. The valve proper is mounted horizontally with the stem visible in a space between the body of the valve mounted on the pipe and the round top of the valve which is flanged and so if you look carefully you will see a metal rod (stem of the valve) with a slot around its circumference. You can take the tip of flat blade screwdriver and insert it in the slot and then lever the valve back and forth to check if it is moving freely (against spring action in one direction) or not. If it doesn't seem to close easily with the help of the built-in spring, then I would spray the base of the stem with solvent from a pressure can (such as WD-40 or carb cleaner) while moving the stem back and forth.  Then see if that solves the issue.
Other than that, when it stalls the next time, listen for whether you can hear the fuel pump run (coming from the gas tank in the rear) for a second or so when you first turn the key to the run position (which is normal). If not that is significant so let me know. Also try checking for spark when that happens. And finally keep checking for fault codes.
Roland
PS Sorry for the delay but I just found your question in the pool where it had been referred by Kevin.
Please 'rate' my answer, and where you see the question about 'volunteer of the month consider a 'yes' if this has been helpful. Thanks


---------- FOLLOW-UP ----------

QUESTION: Hi.  I just wanted to let you know that a technician replaced the ignition switch, and that has cured the problem for me.  Thanks again for your assistance!

Answer
Hi Joe,
Thanks for the report. I guess that qualifies as "something flaky in the electrical part of the ignition system" but I couldn't recommend you replace the switch without measuring the continuity of its switch contacts. I'm glad it is resolved now and I'll keep that straightforward possibility in mind when I get similar questions. We often forget the simple when dealing with these modern vehicles.
Roland