1989 Buick Regal Custom
3.1 V6


The engine will run but really rough. sounds like misfiring. I replaced the wires, plugs, igintion modual, coal packs fual filter, fuel pump checks out fine. Checked the TPS "<NOBR>Throttle position sensor" and disconnected it it ran better but is still dies when you rive on it.
</NOBR>Edited by: kewill_2000

how old is the catalytic convertor?

it's can be as said Patrick a problem on the exhaust, like to many
restriction on gas flow. You can also try to clean the air intake
system and vaccum. Shooting carb cleaner in the throttle body often
help. You can also by cleaning stuff that will clean the vaccum part.
The stuff pass by the PCV valve.

Check the firing order again just to make sure. Serioiusly. I've tuned
up cars a million times but the 3.1 are easy to get the wires crossed.
If it's not the cat try the crank sensor.