mustang is bucking and running like crap

[donsbad68]

Ok, my 1989 5.0 5spd is running like crap. I have replaced the following parts and the car still bucks in every gear like it has a miss, cruising it bucks at almost any RPM and it acts like it hits a wall at 5000 RPM just boom big time jerk and it wont pull anymore. In extreme case it sounds like it pops out the TB. The timing is set at 12* with the pill out.

New parts:
tune-up
O2 sensors
TPS
EGR
Idle air

 

[Camman]

Troubleshooting so far?
Any codes?

 

[donsbad68]

The CEL light comes on only when bucking and goes off when idling or sometimes goes on and off

 

[HISSIN50]

The CEL light comes on only when bucking and goes off when idling or sometimes goes on and off

And what code is stored?

 

[donsbad68]

no clue have no reader and the nearest parts store is about 50 miles away, wouldnt like to drive it that far like this, the bucking on the hi-way at 75 would get old real fast.

 

[donsbad68]

also would like to say its good to see the famous hissin subscribe to my question

 

[txgunrunner]

my car is running like that and dying on me and cleaning the idle air control was suggested. i havent had time to clean mine though. good luck

 

[donsbad68]

my idle air is brand new

 

[txgunrunner]

duh, sorry

 

[donsbad68]

quite alright anyone else have any ideas?

 

[HISSIN50]

no clue have no reader and the nearest parts store is about 50 miles away, wouldnt like to drive it that far like this, the bucking on the hi-way at 75 would get old real fast.

Here is some info on retrieving the codes with a paperclip/jumper wire, etc.
That is where i would start. Your repair manual should also have a run-down on pulling codes.
The thing with EFI is that it is a bit more complex than a carbed set-up. So it is nice to utilize the on-board diagnostics to help find issues.

Are you sure your plug wires are up to par? One can get a nasty miss if they are bleeding.

Good luck.

 

[donsbad68]

plug wires and supporting ignition items are all brand new.

 

[Scott_95GT]

Harmonic Balancer could be on it's last leg.

 

[88GTStreetRod]

My car did the same thing. I replaced everything and nothing helped. What fixed my problem was the mass air meter. I clocked the meter 90 degress.

 

[donsbad68]

problem is fixed! I broke down and went and bought a 20 dollar code reader, and for next to nothing fixed the problem. Turned out the TPS voltage was way too high and the EGR valve didnt have any vacuum! Thanks for the help guys she is running like a champ now!

 

[HISSIN50]

Glad you got it fixed. Knowing the codes really helps.

 

[Camman]

Right on!!! Thats awesome that you fixed it with the codes.