Lag/delay in throttle response

[ARTTII]

I converted a '66 mustang to fox style EFI using parts from a 1993 Mustang LX 5.0

I'm experiencing a slight delay in throttle response, like when you snap the throttle it almost bogs or delays then takes off, ALSO, when you let off the throttle there is the same delay, meaning the rpms don't drop right away, it seems to hang for a slight pause...

Anyone ever experience this problem?? Otherwise EFI is in and running great!!

 

[90mustangGT]

Check the TPS sensor first, and get some codes while you are at it.

 

[86bluecobra]

check the codes. It could be any number of things causing this issue.

 

[superhuaman]

does your harness have a provision for a check engine light? if not, it would be a nice addition. i would say tps, mass air sensor, or lean mixture but pull codes first.

 

[GTOreturns]

I have a 93 lx and have the same problem. It runs great, but has that "slight" hesitation when I punch it. My TPS is at 094.