the car is fine when started but, when put into gear at normal acceleration it starts stumbling and sometime backfires.

the issue seems to be getting worst with time and no check engine light is on.

it also feels like a lost in HP.

 

Do you have any leaks of any sort under your car as that is what mine did when I blew a head gasket... Also could mean plugs could be bad several things could be wrong... Could be short somewhere in your wiring that will even cause that i had a camaro that had bad wiring in it that caused this... Any thing you have done to it recently or changed?

 

I've had that problem before. Once it was the fuel filter. Once it was the inlet elbow had slipped off the throttlebody partially. Once it was the optispark. And once it was the plug wire coming from the distributor. Most likely in your wiring/ignition or fuel. GL

 

Are you loosing coolant?could be the water pump drippin down onto the opti to cause this,with no codes.Check your driveway for leaks.Otherwise,plugs and wires(coil wire#10.Hope this helps.)

 

i has been leaking oil around the crank it looks like.
i have change the wires, plugs and, the fuel filter.
i was thinking opti but never had any issues.
just wanted to see what others thought about the issues before a change out.

 

I replaced my opti at 100K miles and it made a huge difference. If you have high miles and its the factory original, it would not be a bad idea to replace anyway. I always look for a way to replace the cheapest stuff first and then go for the ones that are just old and need it eventually. I cleaned my maf and it made a difference.

 

Check for codes. There are codes that do not turn the SES light on.

Check the fuel pressure.

Do the basic checks before jumping on the "it's the Opti band wagon".