have a 1994 voyager with a 3.3l engine. it run great on the road, but at times will not idle. all new plugs, wires, fuel and air filter. had scanner on it, no codes, all data ok. will not act up all the time. what is the most likely cause? is this a popular problem?

If you're nt using synthetic oil I suggest to do so now. Another reason is the air flow in those engines is pretty high & the stock air filters get dirty pretty fast, suggest changing them every 2,000 mile.
If you're running air conditioner alot that is another reason, it robs electrical current from your ignition system, did you have problems w/ your A/C Yet?

Those cars w/ that engine is common all thing suggested above has been knowned to help

Good Luck

After driving for a number of months and with changes in temp between summers and winters some gooie stuff builds up in the throttle body.Normally it has to be removed and cleaned physically using some chemicals and wirebrushes etc.How ever spraying some carburettor cleaner fitrvtly on to the throttle plate esp. along the edges
while accelerating could clean up the gooie stuff and when the accelarato is released the throttle plate closes back to the required area leaving the right amount of air for ideal idling.
Try it out its easy and could save you hundreds of dollars!!

After driving for a number of months and with changes in temp between summers and winters some gooie stuff builds up in the throttle body.Normally it has to be removed and cleaned physically using some chemicals and wirebrushes etc.How ever spraying some carburettor cleaner directly in to the throttle body while accelerating could clean up the gooie stuff and when the accelarato is released the throttle plate closes back to the required area leaving the right amount of air for ideal idling.
Try it out its easy and could save you hundreds of dollars!!

After driving for a number of months and with changes in temp between summers and winters some gooie stuff builds up in the throttle body.Normally this has to be removed and cleaned physically using some chemicals and wirebrushes etc.How ever spraying some carburettor cleaner directly into the throttle body while accelerating could clean up the gooie stuff and when the accelarator is released the throttle plate closes back to the required position leaving the right amount of air for idling.
Try it out its easy and could save you hundreds of dollars!!

try changing pcv, sometimes it gets sticky

I don't know if the 3.3l has it, but my 3.0l has an idle air control motor that is known for going out- it controls engine idle. Mine does it too but it hasn't been a consistant enough problem to warrant the cost of replacing.