no high idle when cold/ tech is erratic

[Bel-air 454]

i have a 97 dodge caravan. it will start fine but it will not idle up when it is cold. i have also noticed that the tech is jumping all over when driving down the road. i have have some problems before with this van. the biggest problem has been the the egr vacuum switch. i also have had problems with misfiring and the cooling fan not coming on. the van has a 3.8 with 285000 miles.

[HeadlessHorseman]

I have a '96 Caravan with the 3.8 and 223,000 miles on it... I had the idling issue you described some time ago. I removed the snorkel from the air intake and, with the engine running, shot some spray cleaner into it to clean it out. It has been running great ever since. Make sure the cleaner you use is correct for your fuel system. Stuff for fuel injection and carb systems are different. You may also wish to shoot the linkages around the intake system with the same cleaner as well and then shoot a little WD-40 for lubrication.

As far as your tach issues, it sounds like you may have a sensor or two to check out - I had to replace the crankshaft positioning sensor because there was a time when I could start the engine, but the RPMs would speed up, slow down and cause the engine to stall. My parts guys tell me that this is a very common problem.

AutoZone will hook up a diagnostic tool to your '96 and tell you if you have any unresolved error codes. That's probably a good place to start. You can accomplish the same thing by turning your ignition switch on and off three times, leaving it in the on position on the third twist - and count the number of times the lights flash to get your codes.