Expert: Roland Finston - 8/2/2011

Question
QUESTION: Hi I hope you can help..I have 1998 minivan town and country LS 6 cilinder 3.8 . Well, after I drive my van,I turn it of..and after a time (mins, hours,) I try to go on my way and it does not star..I just to disconect de batery for 1 hr, and it star it again..The mecanic has change the map sensor,cam shaft sensor, and another thing,,) The problem continues to happen..I leave it hous and some times days and it stars agai,,now on the dash boar it appears service engine, alarm set, an the abs lights...an the speedometer, gas gage, watter temperature and RPM does not move..whe it works (when the van starts.. can you give some ideas

ANSWER: Hi Javier,
I am not clear about when the gauges/warning lights do or don't work when the van starts or doesn't start. Please explain again that observation.
What are the fault codes now: turn 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 the miles reading change to show instead 4-digit number(s) preceded by a P. Let me know what numbers appear.
Roland

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QUESTION: The van works well for some time..days or simple weeks. But sudently, it will not star..and after trying several times turn it the key. On the dash board all the signs (service angine, alarma set, set....) they light up..
I found out that, disconecting the batery for some minutes (30-60min) it start it again..and all the gauges funtion well..
The mecanic first toll me that the problem was de (spanish arbol de levas and the cigueñal) sensors on the engine that moves the pistons and valves
It fubtion well a few days..and again . I bught the map sensor..and again it happen.. Referin to the sdash board..When the van work after the insident..Tha gaeges on the dash board they did not work..But the van move  Ok...I hope this other explanation can help you more to understan me
I laredy have taken to several mecanic to make a computer analisis an all said Its all A O K....sow again can you help me

Answer
Hi Javier,
I understand the situation. I have two possible repairs to try.
First if the exhaust gas recirculation valve (egr valve) which can become sticky in its action and then stick slightly ajar. When that happens the mixture will be too lean when you try to start the engine. If you remove the fat intake airhose that connects the air filter box to the throttle body you should get a view of the egr valve just below and toward the front of the engine from the place where the airhose attaches the the engine (the throat of the throttle body). It is mechanically bolted to a pipe that comes from the center of the exhaust manifold located behind the engine to the throttle body area. It has a round top with a vacuum hose connected to it, and in the area between that top and the actual body of the valve which is bolted to the pipe there is a flange with openings wherein you will see a thin rod which is the valve stem. It moves back and forth between the body and the round top section, spring-loaded in one direction. It has a circumferential slot into which the tip of a screwdriver can be inserted to allow you to test how freely it moves. If the spring action doesn't appear to positively return it to the fully down position then you spray some solvent such as WD-40 on the stem where it enters the valve body and then lever the stem back and forth gently to loosen it up.
That is all there is to it.
Give it a try. The other thing to do while you have the air hose off it to clean the butterfly valve plate in the throat of the throttle body as well as the throat itself and the small air passageway at the inside surface of the throat. Clean both surfaces of the plate. Use a Q-tip moistened with solvent for this task.
Finally, do try the ignition key/switch technique I told you in the first answer as a fault code may appear that will tell us something else that might be wrong.
Roland