Engine Miss

My wife’s 1999 Plymouth Voyager seems to have an engine miss, but basically only when going up a slight upgrade between 45 and 65 mph. Any ideas?

Too many - unless you say something about the maintenance history of the van.

spark plugs
wires
ignition coil
fuel filter
air filter
fuel injectors
the list could go on…try to say a little something about maintenance with regards to the basics.

Van has 120,000 miles now. Three years ago, at 85,000 miles, had reputable service center do tune-up. They replaced spark plugs, distributor cap, rotor, spark plug wires, air filter, fuel filter, and pcv valve. Also, did fuel injection service. It has run great since then until several weeks ago.

That’s a good 35K miles ago. I’d be ready to toss in new fuel and air filters. I would also ask someone to check the fuel pressure, and inspect all of the ignition components again. A new fuel filter might actually do it as a miss under load commonly comes from fuel starvation - but that’s also a good reason to check out the fuel pressure.

Is the check engine light on?

No. We have never had a check engine light come on.