1995 mustang gt gt40 crate swap on going idle issues

[dcevil79]

Hi everyone i am new to the site and in search of answers. I did a engine swap on my mustang gt to a ford crate motor gt40 with and x303 cam and x303 heads i added a cobra intake off a 94, a inch bbk intake spacer to clear the valve covers, 30 lb injectors and mass meter from brothers perfomance a 70mm throttle body,stock ignition exc for the coil,cold air intake not k&n because the problems it has caused me in the past,i have replaced the tps,iac,coolant temp sensor,checked for vaccum leaks and replaced the upper intake gaskets.My tps is set at .98. HERE IS MY PROBLEM it idles like poop and stalls out when in gear i set my idle at 750 rpm's timing is at 13 degrees and i am sick of paying someone to fix it then it's right back to crap. I dont own a scan tool but have the basics to trouble shoot. so anyone out there that can help i could use it alot!!!!!

[lilred86]

You have got to dump that 95 computer! Ford in 94 changed the EEC lV settings in computer. You need a A9L computer from a 89-93 Fox. Give MV Performance a call and ask for Tim Mathley,he can lead you in the right direction on this swap. Another problem seems you have to big injectors.24lb injectors are plenty for your combo. They are probaly running to rich at idle with that wild X303 cam. What's your fuel pressure? You need an adjustable regulator and fuel pressure gauge. At idle with vacuam attached,pressure should be 36-38 psi and 40-42 with vac. hose off. Do you have an AODE tranny with a stock stall? If so, thats why your stalling in gear. You need a 3000-3500 stall with that X303 cam to smooth out your idle and stop the stalling in gear. I hope your runnig at least 3.73 gear, better yet would be 4.10's with the heavier 95 body. The 94-95's were harder to tune because of that weak computer. In the end, a custom dyno tuned chip needs to be made for it. Good Luck!!