Originally posted by The_Robinator:
Hugo - it always stays running, as long as I don't shift out of PARK....will your water-splash test still work if I keep it in PARK?



If there's a problem with plug wires the problem will be all the time reguardless of what gear you are in.

It is possible that the IAC valve intermittently open when you select the transmission out of park. When in park or neutral the transmission doesn't load the engine. But when you go into drive or reverse the IAC valve is supposed to open to let more air into the engine to compensate for the load applied when the transmission goes into gear. If the IAC valve doesn't open the load applied to the engine can be enough to stall it if its just idling.

It's probably something in the transmission.

When in park the transmission hydraulic circut goes onto open loop and on some transmissions is actually shut off. ultamitely it prevents it from making pressure in the torque converter, but the pump section still moves oil throughout the trany for lubrication and cooling. The neutral switch is one of the switches and sensors that tells the computer the shift lever is in neutral or park so it commands a valve in the transmission to make the torque converter to stop making presure.

There is another feature of the transmission that "locks" the torque converter to give a more positive power transfer from the engine to the transmission for better fuel economy. This feature is electronically controlled by the computer which receives inputs from several sensors and switches, the neutral switch is one of them. When the system is working properly the torque converter will only lock when you are moving and usaully in the upper gears like drive and overdrive. If the torque converter locks while its in 1st gear and you are going slow the load applied to the engine can be enough to stall it, like leting the clutch out with a manual transmission if you are moving too slow for the gear you are in.

I have a feeling that the problem lies in a valve or sensor inside the transmission. These electronic units, once they start to act up, usually work ok when they are cool, but as they warm up their problems are aggrevated.

I suggest you take your car to a transmission shop that has experience dealing with Ford electronic controlled transmissions. They will have the equipment to hook up to the transmission to test and check the pressures and operation of the various valves and sensors while driving. This way hi=opefully while during the road test the problem will present itself.

Sorry I can't pinpoint a problem for you. But at least its another idea on an area to look at for troubleshooting.

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