Dodge Repair: 2000 caravan wont start

Question
QUESTION: My wife was told my battery for oir 2000caravan needed replacing. She wenr to a local autozone to purchase a new one.she drove our minivan there went inside to buy a new battery when she came out could not start van, with the old battery or the new one.several mechanics said it jumped time replace the chain .did that still wont start any ideas

ANSWER: Hi Andrew,
Which "chain" was replaced as the result of "jumped time"?
Which size (L) engine do you have? Where is the vehicle now?
Did anyone check for diagnostic fault codes? These are 4-digit numbers preceded by a P which may shed some light on why it won't start. You may be able to get them using the ignition key: "on-off-on-off-on and leave on" doing that in 5 seconds or less elapsed time. Then watch the odometer window to see if the mileage reading is replaced by a such a number. If not, then a plug-in code reader is necessary which you can buy for under $60. Or a shop would do it for about $40 but you would have to have it towed there for that. The reader plugs into a socket under the dash next to the steering column. Let me know what number(s) you get and we'll go from there.
When you say "won't start" do you mean the starter motor cranks the engine but it won't catch and run, or do you mean the starter motor won't crank the engine at all?
Roland

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

QUESTION: I replaced the timing chain as well as the oil pump since I was there. My caravan has a 3.3 liter v6 flex fuel motor init.I tried the on off on off likeu suggested but didnt get a code.I feel like Im oveelooking something   the reason I say this is because this all started happening the second a new battery was installed. Is there a reset on this model by any chance? I know im getting fuel air and fire.

Answer
Hi Andrew,
As to the code readout, did anything appear in the odometer window such as "done" or was there no change shown? I know it works for the '02 model but not the '99 model so let me know.
If you got a "done" that would mean no codes, otherwise if there is a 'hidden' code you would need to borrow or buy a code reader.
The one thing that is often not detected by the pcm and thus can cause a no start without there being a code is the exhaust gas recirculation valve can be cruddy and fail to close tightly when you shut of the engine. That then leans out the mixture too much to allow a start.
Look at the egr which is located in a narrow diameter pipe that branches off the right side exhaust manifold towards the throttle body. It has a round top operated by a vacuum line and between that and the valve body there is flange inside of which you will see the valve stem. It has a slot into which you insert the tip of a screwdriver to move that stem back and forth against spring-action in one direction that tries to close the valve. Spray the stem with WD-40 or similar solvent then exercise the stem to make sure it is closing to a dead stop. Then try to start the engine.
Roland