2002 Chevrolet Corvette Z06: Injector Flow Report

Yes whos going to buy a car that pings in the midrange rpms.

Try seafoaming it.

I'm lovin' all this technical engine stuff. Keep it coming!

The midrange RPM range puts the highest load on the ignition so a hot spark plug could cause pre-ignition but a misfire 'should' throw a DTC.

Does it pass the OBD-II emission test? All sensors ready?

I'm with jefe - keep it coming. Don't whitewash over the challenges when buying a used performance car (or any used car). Instead dive in and start searching for the fix taking us along for the ride.

Have you pulled a plug? How's it look? Right exact model?

I know this sounds crazy, but has anyone thought that maybe they got the Z06 knowing it knocked to try and fix it?

I would have been cool if that was what had happened. But I would be furious otherwise.

i like the fact you guys have all these problems. a lot of people out there like to throw around the idea that you could buy a used car and it'll run circles around a new car for less money. this is a nice reality check for them. there are many potential problems, not to mention maintenance. (that is extensive and costs a lot)

Plugs are an easy check at this point, might as well do it right? I suppose you could test the MAF if you found the spec in a shop manual and tested it with a volt/OHM meter.

Have you guys done a compression/leakdown test on this badboy yet?

Have you guys scanned the car to see if the PCM is commanding KR (Knock Retard)?

I wonder how much $$$ you spent already on diagnosing/trying to fix this. Don't make it a 100 000 project, it's just a freaking old Corvette. Dump it and buy another one.

This car is such a POS. It makes for an interesting read though...

Broken record time, do the cheap basic tune up stuff: change the filters (including fuel), change the plugs, read them to see what clues they give, clean the mas air flow sensor, check for vacuum leaks w/a can of quick start. Then take it to a Vette specialist. The cars not a POS, it's a used performance car. They ignored the basics & didn't take it to a specialist for an inspection before buying it. Here's a link for you: http://www.edmunds.com/advice/buying/articles/78387/page008.html Here's the line you should have paid attention to: "If you like the way the car drives, you should still take it to a mechanic for a thorough inspection." :)

Being wrong seems to be a hobby of yours Jason. You'll make a good husband.

so how much would the average person be out right now if they were paying for this stuff?

haub: "Try seafoaming it."

Seafoam is one of those things that everyone does and doesn't tell anyone before they do it. If it works, they tell the world. If it doesn't, they keep it to themselves.

In other words: IL tried Seafoam. It didn't work. They're not going to admit to having tired it.

;)

majin_ssj_eric says:

09:09 PM, 02/26/10

"This car is such a POS. It makes for an interesting read though..."

Are u serious?

Fortunately the majority of people here actually suggests solutions.
Don`t surrender guys, keep on going.

The response from so many here explains a lot about the American consumer. One thing goes wrong and the immediate solution is to sell it and buy a new car.

Wondering how much of this you'll encounter...

http://autos.msn.com/research/vip/Reliability.aspx?year=2002&make=Chevrolet&model=Corvette

I love how non-Americans can smugly lump all Americans together. Just like all Muslims are terrorists, all French women don't shave their pits, and all Canadians love hockey and drink Labatts... all Americans apparently prefer to dispose and buy new.

Yeah, it's also in American culture to dump something if the cost of owning it is greater than any benefits. That's why we have things such as standards for service and expectations of quality.

I've had cars I've loved and blown $8,000.00 repairing over the course of a year only to have something major (engine) go wrong. I should've gone with my gut and sold it.

That said, Edmunds trying to fix this old Corvette is insightful (and may be damning of General Motors, we'll see.)

"may be damning of General Motors, "

May?? Two guys have vettes at work. Both are only driven on the weekends and both are driven by guys over 50. Both cars (an 06, 07) have had a lot of electrical problems and have driven them crazy. One had a ECU failure which left him stranded 100 miles from home when it was less than a year old and the other never left him stranded but both power window motors have gone out and the drivers seat motor crapped out. Along with a power steering pump and an A/C compressor. When I asked them they both said they loved their car but wished it was built a lot better. Neither of them have had engine problems that was not related to the ECU. Vette owners remind me of Harley Davidson owners from the 60s and 70s ......people who owned them had to love them because they drove you crazy with problems....but people loved them. Harley has changed since the horrible AMF owned days....hopefully Chevy has got it together with the new models.

"Even if the four worst injectors somehow managed to find themselves in same cylinder bank, it'd only be 4% lean on that bank and not the 14% reported earlier by the ECU. This suggests to me that the MAF is underreporting the actual airflow."

Remember that time you guys took apart the intake and showed us all a VERY dirty throttle body??

And then a bunch of people said "wow, thats really dirty, you should check your air filter and intake assembly to make sure there aren't any holes because you might be getting irregular air flow readings at the MAF sensor."

Then you guys didn't listen to anyone's comments and continued on your merry way?

MAYBE YOU HAVE A CRACK IN YOUR INTAKE TUBES AFT OF THE MAF SENSOR!!!!

Well said, stoppre75. Jason, you're on the right track suspecting the MAF is showing less air than is actually getting into the engine, creating a lean condition and the pinging. It doesn't explain why one bank is more lean than the other, since both banks consume the same air flow from the throttle body. So there could be a faulty O2 sensor somewhere as well.

The clues are right there in front of you:

1) dirt on the front side of the throttle plate, indicating dirty air is leaking in past the air filter. That dirt on the throttle plate is not normal - it should be spotlessly clean.

2) Rat poop found on the intake manifold. Chances are very high the visiting rodent chewed on some intake tubing, air filter, wiring, or all of the above. Few rodents just come to the engine, poop on it, and just leave, without doing more damage.

I meant to add that the dirty air leaking in past the air filter is likely getting in between the MAF sensor and the throttle body (downstream of the MAF, but upstream of the throttle plate). I would CLOSELY examine the intake hoses, air bridge, clamps, etc. in this area for damage or leaks. Another way to confirm that dirty air is getting into the engine is have the Blackstone oil analysis done on the engine oil - if dirty air is getting in, the oil results will show a high silica content.

Agree with stoppre75 and stingray454. The problem was right there in front of you all along.

Have you guys tried waxing using a Clay Magic bar?