Have a 98 mustang GT 4.6 with this issue:
1- When the car is cold the idle, both in park or drive is fine and acceleration is fine as well, no noticeable issue. Car runs as smooth as a "baby's A***". Now, once the engine reaches normal operating temperature sometime around 3-5 minutes, the issues starts
A- Idle is rough both in park and drive. needle oscillates between 500/1100 RPM and engine feels like it's going to die. Sometimes have to tap accelerator pedal to insure it does not die on me at a traffic light.
B- Car accelerates very rough, feels like an engine misfiring (it's not 'cause it's fine when cold), and I have to floor the pedal for it to pick up speed and stop vibrating.
I'm afraid to take it to a shop 'cause I will pay the price again, just took it out of one a month ago after 5 day diagnostics/$1289.00 (somehow they needed 5 days to figure out the issue) and all it needed was a fuel pump in the end. Hope not to have to go that route again....
Already cleaned the throttle body, cleaned MAF, replaced AIC, checked TPS, replaced plugs and wires. O2 sensors should be good, they start working about 30 secs after ignition so the car would not be smooth for 3-5 minutes if they were bad?!
Any real good ideas?
Thanks
1- When the car is cold the idle, both in park or drive is fine and acceleration is fine as well, no noticeable issue. Car runs as smooth as a "baby's A***". Now, once the engine reaches normal operating temperature sometime around 3-5 minutes, the issues starts
A- Idle is rough both in park and drive. needle oscillates between 500/1100 RPM and engine feels like it's going to die. Sometimes have to tap accelerator pedal to insure it does not die on me at a traffic light.
B- Car accelerates very rough, feels like an engine misfiring (it's not 'cause it's fine when cold), and I have to floor the pedal for it to pick up speed and stop vibrating.
I'm afraid to take it to a shop 'cause I will pay the price again, just took it out of one a month ago after 5 day diagnostics/$1289.00 (somehow they needed 5 days to figure out the issue) and all it needed was a fuel pump in the end. Hope not to have to go that route again....
Already cleaned the throttle body, cleaned MAF, replaced AIC, checked TPS, replaced plugs and wires. O2 sensors should be good, they start working about 30 secs after ignition so the car would not be smooth for 3-5 minutes if they were bad?!
Any real good ideas?
Thanks