What are the symptoms of a bad EGR valve?
 

I just bought a 1990 Aerostar from a private party, and the guy says that the EGR valve is going bad. The symptoms that I can definitely notice with out having any prior experience with Aerostars is that it is real sluggish at times, but at other times it runs like a top. When you push on the gas while it is being sluggish it almost feels like it is trying to come out of gear in very quick bursts (automatic trany), especially on hills. Starting it is a major pain. It won’t start unless you peg the throttle to the floor, and even then it takes 1 - 2 minutes of trying at times, and I think it has a easier time starting when cold. If you peg the gas while it is idling it will try to bog down or even die, bug at higher RPM it has great throttle response.

Are you sure your Aerostar has an EGR valve? Neither my '91 Ranger nor my '95 Aerostar have one. I would do a tuneup and clean the MAF and then see how it behaves before you go chasing down any problems. In many cases, that's all it will need.

Thanks Mikeman.
I only have basic knowledge of auto mechanics. I know my way around old school motors and such, but when it comes to more modern things like “EGR” and “MAF”, I am clueless. What is a MAF and were can I find it? Is there anybody else that can comment of whether my Aerostar should have an EGR valve? (I am going to make a different post on this subject)

Also, I am leaking oil somewhere around my exhaust manifold. I haven’t had a chance to see whether it is a crack or a bad seal yet due to limited visibility, but could this be the cause of my problems?

Gas to the floor sounds like a bad idle air control. See the sticky at the top of the explorer forum about bad idle air control valves. It's the exact same situation with the Aerostar as with the Exploder 4.0.

Thanks aletheuo. I just read the sticky and it sounds very similar to what I’m going through. The guy I bought it from even told me that there would be times were I would have to double peddle it until “I fixed the EGR valve” (which I’m starting to wonder if my van even has). Today on the way home from the pharmacy I had to really baby the gas peddle any time I let it drop down to an idle, and even then she died in the middle of a few stops, but at this time I hasn’t been bad enough for me to have to double peddle it.

Could also be a bad sensor in combination... in my experience it's always good to check the ecc engine temp sensor, too. Get engine up to normal operating temp and then disconnect the sensor (the two wire one just above thermostat housing - take off throttle snow shield and it's right in view) If it runs better/more consistent without it then you have to replace it b/c it'll run aweful when cold when it's disconnected. JR

"What is a MAF and were can I find it?"

Try this link; http://www.glue.umd.edu/~singletn/web/pages/ping.html

"Also, I am leaking oil somewhere around my exhaust manifold."

I'd guess that you have a leak coming from the valve cover gasket. The gasket is close to the exhaust port and gets pretty hot.