ALL I want to do is sell the car so I can get a ls-1
OK my pal is a tech for saturn so he puts his fancy scanner on it and go for a drive everything working good but car stumbles and bucks at low rpm and putting around. The funny thing is if you floor it or drag race it runs perfect not a miss or stumble at all. He said its probably the opti he said its got to be a secondary ignition issue. So i put a new gm opti and still runs like crap.
I replaced wires/plugs and ignition module is a year old. 02s are brand new all the obvious things check out ok or are new.so know ses light or any problems when the $2500 scanner is hooked up
all the sensor readings were good 02 air sensor all that even when the car would buck and stumble.
I don't know what to do????
Its getting me so pissed when I drive home from work at night it stumbles and lunges forwartd in stop go traffic I just slam it in 1st and floor it sideways half the time. I realy hate lt-1 cars I think GM realy screwed up with the opti crap ignition thing!!!!!
someone please help me

Oh yeagh its a stock 93 Z-28 camaro 6 speed no mods to the motor just exhaust/suspenion

 

How old is the coil? What do it's connections look like? How about the connector at the opti, what do it's pins look like? Have you checked the condition of the fuel system? Filter, pressure or injector cleaning? What about a dead cylinder? Does the oil smell like fuel? What about a sticky EGR?

Seems like you got some work to do.

 

There are a lot of things it could be, as usual, people always blame the Opti.
Check everything said above and also check;

mass air flow sensor
EGR valve

Good Luck and let us know what you find

 

I'm chacing the same type of problem, did all the ignition, checked fuel, checked vacuum, etc etc. Right now I'm leaning to bad knock sensor or bad PCM, my car pulls up to 15 degrees. Go check your knock retard.


Brian

 

I have no MAF or egr. I will check the knock sensor and connectors and go over the fuel system again

 

i know how you feel when these cars arerunning good their is no better feeling in the world, i love driving lt1's, but stumbling and bucking like you said makes you want to drive it off a cliff and get something new. it could be so many things from opti to wires to plugs to new coil good luck.

 

I still need to check my knock sensor and fuel stuff. I replaced the IAT just for the heck of it. Could a bad coil do this? I thought if the coil was bad it would just not run or stumble at WOT
I have a extra coil I can try