[CELIA]

1993 Mustang 2.3L Lx(4 cyclinder) :Rpm's won't go above 3000.We have changed the fuel pump and filter,PCM,checked throttle position sensor,mass air sensor,and disconnected exhaust to rule out cat converter(also changed mufflers to dual flow- masters).When checking codes it shows a 998 code /hard fault ,this code only shows up with engine running(reason why PCM was changed out).:headscratch:Any info would be greatly appreciated.

 

[66restomod]

Im guessing it's an automatic? you need to test the solenoids in the tranny. One or all of them has pry failed.

 

[NavySVO]

Will it at least rev over 3k RPM in park or nuetural?

How about engine timing. This shows the symptoms of the cam timing being retarded

 

[Amscray88kr]

Feels underpowered?
Rpms wont go over 3k no matter how much gas you give it?
Idles at 500 rpms?

Might be ICM. Thats what mine did. Replaced it and it runs great now.

Buttttt...Dunno about the code you pulled.

 

[66restomod]

code 998 is for transmission control solenoids.

 

[MilkMaster122]

code 998 is for transmission control solenoids.

hes right. thats what you need to get checked out. but the ICM is good to. ive had some CRAZY problems with some of them. and they would even test good.

 

[ExtrmZ]

i would make sure the engine timing is spot on. i had the same problem with my car, and my distributor is still kinda messed up. the spark jumps everywhere, making it run underpowered