Hesitation at WOT

[Jefe]

Hi,
Here is my situation. About a week ago I was driving to work and decided to let the beast loose. I down shifted to 3rd gear and nailed it at about 2000 RPM. As it went through 3500 I noticed a reduction/hesitation in power and my check engine lite illuminated with a resultant code of P 0128. I posted a question on this and C4C5 replied, with his technical prowess, that my coolant system was telling the car that something was not right. It was either a faulty ECT connection/valve, coolant bypass, or faulty thermostat. He recommonded I put the stock thermostat back on, reconnect the coolant bypass lines to the throttle body and check my ECT connection. I accomplished what he recommended, except the ECT, (I don't know where it is, stop laughing), and everything seemed to be running smoothly at low power. My coolant runs about 192 to 194 on the highway and if I accelerate gradually, no wot, it will go right through the RPM ranges with no hesiatation.
HOWEVER! If I go WOT I get this hesitation around 4000 RPM. It seems to smooth out a little after 5000 but the power doesn't feel right. It is most prevelent in 3rd and 4th gears. Any advise??? Here are my stats on my car.

2003 Z06
5400 miles
Vortex Ram Air
High Flow Power Duct
Borla Stingers
X-Pipe
NO OTHER MODS. Yet.

Thanks in Advance,

Jefe

 

[c4c5specialist]

HI there,
Now, I am assuming(sic) that the P0128 is gone now.
Please make sure that the mass air flow sensor is connected and tight, because when the engine twists under WOT, it could come loose and cause the hesitation. Your Powerduct does not flex, so it could work loose.
Then, if that is ok, a scan with a Tech 2 would be the next course of action.
Please keep us posted, c4c5

 

[Jefe]

You were correct in your assumption, no codes at all. Will check the power duct to make sure that there are no leaks! Thanks as always!


Jefe

 

[Jefe]

C4C5,
The SAGA continues!! Made sure that there were no air leaks after the MAF but the problem persists. Still no codes. However, each time before I would immediately get off the pedal as soon as it started hesitating. This time I rode it out a little and the "Check Engine" lite illuminates each time and stays on for about 15 to 20 seconds before extinguishing. Again, no codes are being displayed. I ran the diagnostics, "Option" button held with 4 presses of the "Fuel" button, and nothing. My apologies if I am being a pest but I would like to get more information before taking it to the dealer. Thanks in advance.

Jefe

 

[c4c5specialist]

HI there,
Unfortunately, there must be a sub code occuring that is not being displayed by the DIC.
What I would suggest in this situation is to schedule your appointment with the dealer, and road test with the Corvette tech. Have the Tech 2 attached and recording, while you drive the car to duplicate the condition.
The Tech 2 will record the condition, and you will get invaluable information as to what the problem is.
Please keep us posted, c4c5

 

[Nick Palafox]

Hummm....how interesting. Makes me think of a number of times when I floored the accelarator on my '03 automatic coupe the car seemed to "bog." Once, I kept the accelarator floored to see what would happen but it just continued to "bog" with no indication of increased rpm's and certainly not a racing engine. Most times when it happens it's momentary and when I release the accelarator and then push it down again it seems to run fine. Took it into the dealer with this issue, but they said nothing was wrong/no codes. Someone on this board advised that I should have a software update. Hadn't done this yet, but I will.

...just my 2 cents worth.

 

[Vett-Less]

Walmart Stoped Flushing Auto Tranny

 

[Jefe]

Well I finally found the problem! It was a cracked insulation on one of the spark plugs. Once they changed the plugs, I requested they do the entire set and they did, it runs like a scalded ape again!! Thanks to all, especially C4C5, for their advice and help.

Cheers to all,

Jefe