westc

I posted this on the general discussion thread already. Quick overview:
Bought this 07 Base Manual back in May. 44,000 miles. Car is rebuilt. Had been hit in front. Car drove great. Only issue was a really rough idle; it would idle really high then really low. Sometimes it would even die while setting at a red light. No other issues.
Put on two performance Sprectre airfilters. Changed oil and oil filter (Mobile 1). Still ran fine except for idle.
Do not know what all has been done to the car as far as upgrades. I do know that it has "straight exhaust" and have been told that it does not have O2 senors (if that sounds right).
Took to a mechanic who said it had the code for a mass airflow sensor; bought one from AutoZone; did not correct. Mechanic said he does not work on Vets, nothing else he knows to do. Went to a different mechanic. Also showed Mass Airflow code. He thought the one we got may have been bad. Replaces again. No fix. It was aftermarket as well. Do not know brand. He recommended a tune to fix idle.
Set up appt for a tune to fix idle. The paperwork I have says HP Tuners custom tune; however, the print out I was given says Mustang Dynamometer Test Report on the top. Means nothing to me. I do not know a lot about cars. The car was tuned and supposedly put out more Horsepower, which I did not care about; I just want the car to run right. The tune helped the idle, but, on the way home, I started to notice a bogging down/hesitation upon acceleration, especially around 2000 - 2500 RPM. It hesitates badly sometimes and not so badly other times. When you just cruise, no problems, but when you hit the gas, it hesitates, bogs down. I called the place that did my tune and took it back to them. They did not know what the problem was. I thought it was in the tune. They removed the tune and supposedly put it back on and it did not help. They then thought it may be electrical and checked all my wiring, etc... They also thought it was the Mass Airflow sensor and tried that as well. No help. That made three different Mass Airflow sensors. Basically, they had the car for more than a month and found nothing. I got sick of waiting and just went and picked the car up. Took it back to one of the first mechanics to check wiring, etc... The only code the car will still give is the Mass Airflow, which he wanted to check again, but since we told him we've tried three, he decided against. He checked all wiring, hoses, etc...and found nothing. Now, the car just doesn't run right like I said before. It bogs down/hesistes a lot of the time. It will run good for a while, and then start again.
Then, for the first time this weekend, like 5 different times the car would not start on first button push. It has never done that before. It turned over, but did not start right away. Once, I had to try it three different times.
Today, I called Chevrolet directly. As I was afraid of, the tech told me there is nothing they can do with a car that has been tuned and has the exhaust "cut".
I do not know what to do and just want this car fixed. I love this car and it runs great other than this.
I have read a few threads and had a few responses that it could be anything from dirty fuel injectors, EMC (computer), bad gas, etc...
It's not bad gas, because I've run multiple tanks through it. I have not cleaned fuel injectors, but am planning on buying some of that cleaner you put in your tank.
Please give me some advice.
The Chevy tech said he could recommend two things: 1. get stock exhaust installed along with C Converter and o2 sensors and get flashed back to regular (a lot of money and may not work). 2. Try a Mass airflow sensor directly from Chevrolet/GM ($280). He said he would not use any part like that aftermarket.
Does anyone else have any advice/ideas? I do not want to put a lot more money in this car, but, if I knew for sure what the problem was, I would consider it. I don't want to just go around sticking parts on it.
Please help. Any advice would be appreciated.

silver ls2

I sort of had this problem. First disconnect positive battery terminal. Then tighten up All the intake connectors to your filter. This should fix it. If one is a little loose it does this.

westc

I am assuming you are talking about the air filters? I will do this hopefully by this weekend and see if that helps. Thanks.
Any other ideas would be appreciated.

westc

Another update: I bought some Techron last night to try to clean out the fuel system/injectors, which has been a common respone to this problem. I will try this next time I fill up. I will keep the post updated as to if anything works.

As always, any other input is appreciated.

westc

Just posting to keep people looking. Still no luck with the problem. This weekend I am going to try a few suggestions to see if it helps. 1. Techron in the gas tank, 2. Checking to make sure the bolts/screws holding my air filters in are not loose, and 3. Checking to make sure there aren't any cracks, etc... in any portion of the housing, brackets that hold the radiator.

These have all three been suggestions to me that others say have fixed a problem on their car similar to mine. I will keep the post updated.

On the other hand, if anyone else has any suggestions or can recommend some good Corvette shops/mechanics in the East Tennessee area, it would be greatly appreciated.

cole3

sounds like it could have a vacuum leak somewhere maybe.

pit-man

Did the Tuner mention replacing the 02 sensors ? They can really mess up your idle if not working right, as will a vacuum leak as mentioned above. Remeber the 02 Sensors need to be calibrated to open air before installing.

I would start there first, before moving on with expensive items (that really doesn't sound like your problem anyway).

#3: Do you have Cats still installed on the car ? See if they are plugged up.

westc

If I am not mistaking (as I said before, I do not know a lot about this stuff), since the car has straight exhast, it does not have cats and the tune was made to bypass the O2 sensors (I guess due to the fact that it does not have the sensors or does not use them). I hope that makes sense. As from what I have been told, that it what I understand.

pit-man

They typically turn off the codes to the rear and the front are still on if you have headers. They may be bad.

Gering

OP: Just for the fun of it did you check all of your spark plugs & wires?

westc

Yes, plugs and wires have been checked.

westc

The car does not have headers, but I may need to check to see about the O2 sensors in the back. However, I was thinkning that surely of all the people who have looked at it, that woud have been checked. I will definitely look into it...or have it looked into.