I replaced all the filters, spark plugs, checked the timing, etc. and my engine still stumbles under acceleration. but only when the engine is warmed up after a few mins of driving. The computer isn't producing any fault codes, but i get a check engine light during prolonged idle after cruising. Any suggestions?

it only stumbles when engine is warmed up?? hmm it would make sence if it stumbled when it was cold but.. Maybe your fuel pump is about to die? is your transmition auto or stick, if it is auto possibly try changing trans fluid (and put new filter.. in)

kyle

I'm going to vote bad coil or some other cause for weak spark. A richer fuel mixture as in warm-up provides an environment that is easyer for spark to cross. As it warms up the coil output needs to go up.
If it is rythmic, ground the plug wires one at a time to see witch cylinder it is and check cap, rotor and wire. If it mixes them up or misfires irraticly, look at ingition output ie. coil.
Ross

How can you get a check engine light with now codes? I thought everytime it came on it stored a code.

my guess would be the ingnition control module. it's under the dist cap. when they get old the start burning up and heat makes them act funny. mine stumble for about 1/2 a day before it just started stalling out when ever it got warm. it's only $40 or so at napa, and it's reletively easy to replace. also, the coil would be a lickly culprite, plug wires too.

It's a manual tranny. How much resistance should their normaly be across the plug wires?

That would depend on the wires on hand. Also it doesn't mean they are good because they pass a resistance test. If they are more than a couple years old just replace them and be done with it.