96 Achieva 3.1 runs poorly

I have a 96 Achieva SL 3.1 litre that runs fine for the first few minutes of driving then begins to have lack of power under load, misfire, sputters but does not ever die out. If put in park, engine idles fine, no misfire detectable if in park from 700 rpm up to 4000 rpm, only have problems when actually driving. Changed plug wires and plugs (Bosch Platinums). There was a code for cylinder #1 misfire before i changed plugs and wires, has not reset the code, but is not running much better. The car set for about a year waiting for the money to change the transmission, and also put on new intake manifold gasket. Ran fine before changing the gasket aside from the coolant leak. Runs poorly now. Any ideas of what else to check since there are no codes? Thanks in advance for any help. Feel free to send any help via email to rwever@windstream.net

hi there make sure the ground wires on the bellhousing bolt are not broken

if they are it will run like crap but not die, especially in gear

had this happen a few timeson a few different 90s cars, yes 3.1L 3100 ones
common problem

the wires are on bellhousing stud towards firewall nextone down from the top rear-most one, under master cylinder area, get a nice bright flashlight and reach down by the master cylinder and feel the wireson the bellhousing stud make sure they are not loose or broken inside the insulation

we run a garage and this is a very common problem these are ground for the ECM and injection, not jut achievas but grand ams and other 3.1 cars


very important





good luck

change your plugs use a.c. delco

change your plugs use a.c. delco