I have a 94 with a pro charger on it that I bought used. runs fine and as should except for one thing! going down the interstate holding at 70 mph or there abouts when you are just barely touching the gas pedal it runs rich and boges the engine. you can let up or give it a little more pedal and all is fine. in watching the air & fuel gage all is normal except when I'm running like I stated above. at idle its fine.
I've taken it to two different shops and had both the co2 sensors replaced as well as the throttle sensor and still does it. anyone with the same experence that had sucess in fixing? getting costly to just keep putting on parts!
thanks

 

Suggestions: get a field service manual and learn how to get any trouble codes and post them here. How do you know it's running rich? Post more info about the mods done to the engine. Auto or manual? Has the PCM been reprogrammed? If you don't know this stuff, you're in trouble because you don't know the baseline parameters of your powertrain.

I'd use a meaningful title on the post like "supercharged engine running rich" so people who inderstand the problem will take notice. Posting "help!!" kind of looks like a whiny kid post and you're not that.

Just my opinion and YMMV.

 

How do you know it is running rich? What gauges are you watching?

I can give you a list of suggestions and things to check, some hit and miss. But actually you have a classic symptom of having a bad opti. They run good at speed but then give it some throttle and it bucks, chokes and slows down after it gets hot. Just a thought and something to consider.

 

A whiny kid I'm not, I'm a 70 yr old that when it comes to these modern computerized cars that time has passed me bye.
As for the opti it has been replaced and yes by not knowing what all has been done to the engine makes this difficult.
Even without gages I do know what running rich is but I do have the fuel & air gage to watch. What is strange to me is at 70 or so when just lightly holding the petal at that speed the gage will drop to 10.0 and bog the engine and at any other speed including idling it runs as it should and the gage shows it is?
Anyway thanks for your comments.

By the way my first car was a 33 ford that I installed dual single barrel cards on and split the manifold. Then later cars it was multi carbs, cam, headers and 4:11 gears and go to the drag strip!

Time has passed me bye

Jim

 

I'm not going to offer any more technical suggestions at this time. Possible others might know this but I'm not sure if you are using injectors or a carb. This would help peoples thinking with their comments.

As for working on these cars, having a FSM is the best thing you can have. Every year is specific and a bit different. There is information in there not found anywhere else. It gives you a lot of theory of operation, what sensors are used and how, and troubleshooting steps. I grew up around the auto business, have experience and am an electrical engineer so I have no trouble with the electronics. But I approaching some of the problems I do, and others that have much more corvette experience than me would not do it without the FSM. There is lots of other information out there that can be used in addition with the FSM but that’s your main root resource.

You don’t have to be left behind, you can read in the FSM about how things are done and what makes things work. A lot of the 90s technology is still used today in theory of operation. If you learn about the corvette, you will know much more about the modern cars of today.

Would like to know more about you set up and any additional details and information about the problem. This might help with suggestions for a solution or a direction.