96 windstar problem

i have a 96 windstar i have a problem with what i think is a engine problem. sometimes when driving the van will jerk or buck the rpm's will jump about up about 1000 rpms then back down. I dont have a check engine light on it used to do it only on the freeway but now it also is happing in the city too. the engine has about 78,000 miles on it i had the fuel pump tested its ok changed the fuel filter it seems like its something in the fuel system because its running a little ruff too i just gave it a tune up not to long ago i am stumped on this one. maybe egr valve?

Your thinking is correct - Check the simple and easy things first. Look for vacuum leaks (including the EGR, PCV, hoses, gaskets, cracked intake), check spark plug and wire condition, make sure the intake port valves are operating (vacuum actuated), check the air filter and intake tract, clean the throttle body, test compression, and perform a general inspection of engine electrical connectors.

Even though fuel rail pressure is correct, the injectors could still have problems. If you exhaust the "easy" items and still have problems, a power balance test may be a good step.

I had a similar problem with my 96 Windstar. It turned out that it was my transmission range sensor that was causing the problem. My engine acted like it was losing 4th gear at times, the RPMs jumping up about 1000 or so. My husband changed this and it has worked fine ever since. I think the part was about $50 CDN and he said it was fairly easy to do by himself.

Naomi