Hi my name is Joe and this is my first time posting a new topic,I've read many of the other problemswith other members vehicles and I am very impressed with the various ideas and knowledge found here amd I'm hoping I may be able to catch some of that same help.I just bought off a friend a 1987 E250 conversion van with a 302,the original motor died and the owner installed a 1987 mustang GT motor to help carry the load a little easier,the motor has 32,000 miles. My problem is in nuetral/drive/and park the idle goes up and down and sometimes stalls.
I took the IAC sensor off and cleaned itand did'nt seem too carboned up but I cleaned it anyway just in case,no difference,so what I've done is I jacked the idle up and at least now in drive I don't have to use two feet but the idle in park or nuetral is still up and down,anybody else ever had a problem like this?
Another thing is I'm not to happy with the 302 in such a heavy vehicle,I like driving it around in 3rd gear insted of overdrive because it so low in RPM's in OD I have my foot almost to the floor,I hope that it won't damage the tranny.Any help would be great

 

I'd change the TPS (throttle position sensor), it sounds like it's out of spec... Raising the idle just turns up the voltage sent back to the computer, so it sends more fuel. To check the TPS get 2 straight pins, 2 aligator clips, and a volt meter. There are 3 wires on the TPS. The middle wire and the black or ground wire are the ones you want... Stick the pins in them, then clip the red (+) lead to the middle wire, and the black (-) lead to the black wire. With the key on and engine off you should have .7 to .9 volts, and at WOT (wide open throttle) about 5v. If not change the TPS. You should also check the codes.

 

Did your friend change the intakes in the process of the swap?
My understanding is that the F and E series intakes are of a slightly different design than of the Mustang, with more emphasis put on torque. Along with cam profiles.

Patrick

 

thanks pfogle for the tip,I will try that next and if that is the problem what should I tell the parts counter man i need the TPS for,an87 e250 with a 302 or an 87 mustang GT with a 302,basically,would the two engines take the same TPS and also how do get codes from the computer???The truck runs strong there is no black smoke or anything but it sounds sometimes like is has a huge cam and other times it sounds smooth as you could want it,it does have headers and the previous owner went to Ford and he put the O2 sensor where they suggested,there is no check engine light or anything I wanted to put this information in my post maybe it would help with the prognosis.

Thanks ,
Joe

 

UPDATE!!! Ok ACEsn8s,I called the previous owner and he said he had to change the whole plenum and intake cause the mechanic or the place that took the motor out cracked the old one so,the thats all new/or has been changed.What he told me was everything externally was for a 87 302 van but as far as the internals of the motor it was all Mustang GT. The new computer he bought was also for an 87 302 van so hopefully that answers any q's about that. NOW.
Pfogle,I don't know where the TPS is on the motor I did see something that was bolted on to the side with three wires,I thought that was the TPS but as you described the wires on this were different as the "middle" wire was black and I think there was two orange wires on the left and right maybe that was'nt it,could you elaborate on the location of the TPS?
Thanks,
Joe

 

It's on the bottom of the throttle body, (you will have to remove the air cleaner tubes)...There should be an orange or green, a red and a black..

 

Ok,thanks! I'm off to work rite now but I will check for it tomorrow morning,please check back if you don't mind,you are my only link to repairing this problem and thanks again for the help.
Joe

 

Hey Pfogle!
I checked the TPS as per your instructions,the wires were correct as you said black,orange and green. I tested the green and black wires because the green wire looked like the one that was in the middle actually going into the TPS,so here are the results,at idle with the key on and engine not running the readings were .959 and wide open throttle the meter went to 1. and thats it no zero's or anything just 1. so please let me know whether the TPS should be changed and if so it looks pretty cramped in there should I remove the 4 bolts and take that whole piece off or what?
Thanks again,
Joe