Throttle body swap

Hey yall, i just got a 3.8l throttle body and swapped it with my 1993 1.9l throttle body, its like an original mod for this car and seems to work for everyone. Im having a huge problem with the idle i believe. The car idels at 2500-3000 rpm on park or neutral. If im correct it should be at 1000. When i shift it into drive or reverse it decreases to 1500 rpm. I dont know what the problem could be, so first i disconnected the throttle and kickdown cablse and still the same problem. I was wondering what it could be, maybe the iac, or possibly the sensor on the throttle body itself(dont recall what its called) but i left the 3.8l sensor on it. Should i swap it with the original 1.9l's sensor? Need help asap, thnx.

Maby a bad tps. Thats a pretty big throttle body for that little motor isn't it?

Well its not THAT much bigger, maybe 5-10mm bigger radiums openning, other than that not much bigger, plus others have used it on the car and saw it works perfectly? Maybe i need to cange the MAF from the escotrs to the mustangs as someone else suggested.

Any more information on it? I got a 96 escort wagon that I got free because someone didnt want to fix it. (timing belt broke, bent a couple valves). heh, I still havnt got around to fixing it either... I'v had bad experiences with escorts in the past.

well i tried some shit, neated up the rewiring to the tps and stuff. didnt try the New MAF yet but now i got it to idle at 1500 rpm, and goes to 1000 rpm in gear. Now the problem is if i leaveit in gear for awhile with my foot on the brake, the rpm begins to drop and the car turns of. now im thinig its the kickdown cable. maybe its not in a good position? what u think?

My guess is that the new IAC needs to be altered for the requirements of the smaller engine. The IAC is receiving the same signal as it was before and opening the throttle x%. Bigger throttle body at the same opening = higher idle.

Reprogram the computer for a different IAC value and see how it works.

I know that your car is listed in your profile, but please list it in the message so we know what we're talking about without having to click through your profile to find it.

All that trouble, finally figured out it was just an air leak, woops lol. HATE RUBBER TUBING.