Good morning everyone,

My corvette has been sitting for about 3 months while I slowly replaced the water pump. This weekend I finally decided to put it all back together and now I'm experiencing something very strange with how the car is running.

I have a 95' LT1 with 6SPD transmission. After the pump was installed and filled with coolant I started it up and 'burped' it a few times and decided last night to take it out on a quick drive to confirm nothing was leaking. It has been awhile since I've driven the car but something just didn't feel right. It was like the throttle wasn't very responsive. The car did fire right up and I didn't notice a miss in the motor or anything like that. But it was very difficult to get the car moving from a stop, it felt like I had never driven a stick before. I thought maybe I needed some clutch fluid but i'm pretty sure the clutch is working Ok. I then decided to stand on the throttle a little to see if it would miss. When I did that I actually felt the throttle pushing back on my foot at about 3500 RPM. I have never felt this. Also, the car didn't seem as fast or responsive. I drove the car to the office this morning and it drove down the interstate just fine, no issues and temps were all good. I decided to stand on it again and again I feel the throttle pushing back against my foot, feels like there is a rubber ball behind the pedal.

I'm at a loss. I can't figure out what I would have done during my water pump change to make this change. Could it be a sensor not working? I can't remember how many connections I unplugged to get the water pump out but should I start looking there?

Last bit if information, I have no idiot lights lit up on the dash. That doesn't mean I don't have a code or two still lurking behind the scenes but nothing serious enough to give me an alarm with an idiot light.

Thanks for reading and thanks in advance for any help or advice.

Best regards,
Greg

 

Take a look at that sensor on the water pump

 

Thanks for the reply antfarmer.

Do you know what that sensor is sensing? I thought it was just a temp sensor. Do you know why the sensor would make the car more difficult to drive?

Thanks,

Greg

 

That sensor feeds into your ecm and can do all kinds of funny things. That one goes to your digital temp. What is that doing?

 

I have a stupid question after reading your post about the throttle pushing back on your foot, do you have the ASR on?
Maybe your tires are old and hard and they are spinning. If ASR is on it may be detecting tire slippage and pushing back on the throttle, retarding the timing causing the lack of power. Try turning the ASR off and see if it feels the same.

 

Well, I found the problem...but a little embarrassed to disclose what it was. Driving home from the office last night I was messing around with throttle position and it felt like something was restricting the butterfly valve, like the throttle would only push so far down before it ran out of movement. If I pushed hard enough the throttle would actually push back and I think that was from the pedal flexing a little bit. I thought maybe I left a wrench or something around the butterfly valve restricting its rotation. I opened the hood and realized the cable and slipped off the pulley that rotates the butterfly valve. With the cable off the pulley I was only getting about half the movement of the valve and made it very unresponsive at take off from a stop sign, especially with a manual transmission. Now that I know what the problem was it makes complete sense!!

I very much appreciate the people that responded though as I was just sure I had a sensor or something not working. I also thought it might have been tied to the ASR system because it kind of felt like the throttle was trying to kick back during hard acceleration.

Thanks again for all the responses.

Greg

 

"...realized the cable and slipped off the pulley that rotates the butterfly valve..." No need to feel embarassed.
Actually finding that it wasn't something you did and that you didn't spend hundreds replacing parts needlessly is pretty good!
And thanks for sharing . Another story of doing a little detective work paid off and maybe someday another member with a similar problem will think back on this and say, "hey did you check this....."