1994 5.0 stalls

[Tuna]

i found this mustang that had been sitting for a year or two because of trans problems. So i went through the trans completly, everthing new. I thought i had something wrong in the valve body. So i double check everything and im still having the sam problems. Now im thinking the engine is not working right. The vehicle has 140k hard miles i presume (belonged to college girl). When put into reverse it stalls out with foot on brake. When put into drive the idle goes from 400 rpm to 700 rpm with foot on brake. sometime stalls out completly when put in drive. im not sure where to begin. any help would be appreciated. also ive changed plugs, wire, cap, rotor, flushed fuel injectors with BG cleaner directly at rail, fuel filter is new, and fuel pump is new.

[jayh]

id clean or replace the iac valve- idle air control valve, its on the throttle body

[Tuna]

the engine will idle just fine but put it in gear and it dies. i cleaned the iac valve and no change. could the iac still be faulty? or the passage inside the throttle body clogged?

[jayh]

does it have mods?

sounds like iac to me or a vacuum leak. can you drive it around and see if its down on power or if the eec will go through adaptive learning?

[Tuna]

no mods. cant find vac leak. ill try and go drive it and see what happens

[Tuna]

Did alittle more diag. Vac at idle is 15 in. Compression test revealed about 125 psi all around. Put trans into drive and idle lopes, while in drive vac jumps from 0 to 15. I finally got it out of the driveway and down the road. Not very well though. engine rattles and there is no power.

[jayh]

sounds like the motor is tired and has issues internally, vacuum shouldnt drop off to 0 at idle and 125cranking psi is on the low side

[4eyedhatch]

Just out of curiosity, where is the ignition timing? The compression test does sound low, but if it were fairly even across the board I wouldn't put that as the culprit.