Help me Wizards,
I am at my wits end, if I have any. I have a 94 Aerostar with a 3.0 liter. My dilemma started when I changed my Master Cylinder. My idle started to stumble. The Rear ABS light now stays on. I have been told that this does not apply, but, I submit it just in case. The car ran real rough early in the mornings especially after rain. I took it to a repair shop ( a National Chain) they changed: Rotor , Dist. Cap. , Spark plug wires, Idle air control, R&R idle air, checked the vaccum, they cleaned the fuel injectors, and did an engine analysis. Within a couple of days out of the shop the idle was bad again. I have changed the Oil Pressure gauge ( dips when the idle is stumbling ) , Engine Temp. sensor, Air filter, PCV valve ( it had gunk ), and cleaned the butterfly on the air intake with Carb. Cleaner. The last three items did improved the idle. The idle still stumbles if I get caught in traffic and occasionally I get a check engine light that goes away after I turn the vehicle off. The Van died ( DOA ) on the highway the other night, no check engine though. Smells like it is flooding out. After I was towed home it started up about an hour after it died. The sales clerk at the parts store suggests that I don't need any sensors if the Check Engine Light is mostly off and goes away when I restart the vehicle. I am, going to try the fuel filter tomorrow.
Any other ideas from the Ford Gurus? Thanks for any assistance.

 

Two quick thoughts, what codes do you get on a scanner? Possibly a vacuum line was not hooked up or is cracked or a bad fitting?

 

Thanks for your reply,
I did a visual and listening check on the hoses and I had hoped that the repair shop would have found any leak with their pressure check. I know, I could be asking for a lot. I have never been able to get the vehicle to a shop when the Check Engine light comes on. It very rarely will light. I was told that they can't read anything unless the light is on. Does that information get stored in the computer or elsewhere? Meaning: that the Check Engine light came on and why it was caused to trip? The guy at the Auto Parts store said that I have a mixture problem and if that gets screwed up enough it will cause the light to illuminate.

 

Ford computers store codes, so they should be able to pull any code for what is wrong. Since you say the ABS light stays on, this sounds like when the master cylinder was changed it affected this. They can pull codes for this also.
A good place to find out info on the RABS is here: www.chiltonsonline.com