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Last night I set 2 codes for Bank 1 AND Bank 2 -- engine lean, after 2 runs from 0 to 120. I've been having intermittant problems lately which seemed like dirty injectors, so I've had it into the dealer 3 times now for that. The first two times they cleaned the injectors and the last time they kept it overnight to replace the fuel pump. (which required dropping the tank. NP, they've had it out twice before).

The symptoms include the engine stalling when I push the clutch in at highway speeds, sluggish pedal response with a small lag both on and off the throttle -- not as crisp as normal, although it has good acceleration. One Sunday after a couple hundred mile cruise, wifey and I got off the freeway and it would occassionally stall just pulling up to a stoplight. The RPM's would fluctuate between 300 and 1200 until it finally died. I could give it a little gas and it would be ok, but it wasn't right. So I took it in. Seemed like dirty injectors to me, and they had cleaned them twice before, but the third time they said the fuel pressure was low from the fuel pump, so they replaced it. That was last week, and seemed to have cured the stalling issue, until last night. After I got the check engine light I headed home and it acted like it was going to stall when I got off the freeway. The idle dropped to about 600 and it was idling a little rough, but not as bad as before and it didn't stall. But it's still not right. There were no codes other than the bank 1 and 2 lean after the 2 runs to 120.

I hate to think about taking it back to the dealer but I suppose I'll have to. It's been in there a lot since I bought it last June, (10 times for warranty repairs, twice of which were to fix their own screwups) and this will be the 4th time for this same issue. The tank's been out twice, both axle seals leaked and I've had the clutch and transmission replaced and the diff serviced, all under warranty and all since last June. Do I have a lemon? It's not the same car I bought at any rate.

Sorry for the rant. :mad:
 

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Engine Lean Bank 1 and 2

Is there any corelation between when your your fuel trim problems began and the Blackwing install? Just a thought.

Good luck in tracking down the culprit and be sure to post the result that cures your problem.

Regards
 

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Discussion Starter #3
II on 6 said:
Is there any corelation between when your your fuel trim problems began and the Blackwing install? Just a thought.

Good luck in tracking down the culprit and be sure to post the result that cures your problem.

Regards
I've had the blackwing since about 10K miles and I have 32K on it now. The problems started around 28K.
 

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HI there,
Is the dealership sure that the MAF sensor is tightly connected to the engine????
Are they also sure that the fuel pressure regulator is holding the correct pressure????
You show an 03, based on production numbers, you could have the FFS fuel system.
This would place the regulator inside the fuel tank, where on the older c5, this is in the fuel filter.
Allthebest, c4c5
 

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Discussion Starter #5
c4c5specialist said:
HI there,
Is the dealership sure that the MAF sensor is tightly connected to the engine????
Are they also sure that the fuel pressure regulator is holding the correct pressure????
You show an 03, based on production numbers, you could have the FFS fuel system.
This would place the regulator inside the fuel tank, where on the older c5, this is in the fuel filter.
Allthebest, c4c5
Thanks for the tips c4c5. . I'll check the MAF and all the connections myself, and suggest these other things when I take it in again. I might put the stock airbox back on and see if the problem goes away.

At one point I asked them to change the in-line fuel filter and they told me it didn't have one. Is that true?

As for the FFS fuel system, around 3K miles the driver's side fuel tank had a broken Y connector, and they broke something on the fuel Module while putting it back in, so they "borrowed" one from a new Vette on the lot. (that's a nice thought. Highly unethical. I'll never buy a new car off a lot again! :NoNo: Some hapless victim is driving what he thinks is a brand new Vette, when it's had the tank out and the fuel pump replaced before it was sold to him as new). When they replaced that faulty pump last week they told me I got the new style pump, so maybe I had the old style before. (I hope they didn't rape another new Vette for this pump).
 

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Just a thought along the lines of a possible MAF problem. If the Blackwing was "over oiled", the wires on the MAF could be contaminated with filter oil causing the condition you describe.
 

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Discussion Starter #7
BlackZee06 said:
Just a thought along the lines of a possible MAF problem. If the Blackwing was "over oiled", the wires on the MAF could be contaminated with filter oil causing the condition you describe.
Thanks for your thoughts. I considered that myself. But if they did the injector clean twice, and as I understand, (and please correct me if I'm wrong), they're supposed to take the air bridge apart and spray an injector cleaner right into the MAF. It seems like that would clean the sensor. But, I just pulled the air bridge off and pushed the butterfly open and there was a smal drop of oil on the base of the throttle body behind the butterfly. I wiped that off and felt around inside the throttle body, but everthing else felt dry. I inspected the air bridge and there doesn't appear to be any oil residue there either, and everything looks tight and feels dry.

C4C5, (or anyone else who knows) can you tell me they normally do for an injector clean? Could I have a dirty MAF sensor? Can I clean it myself? I'd rate my mechanical abilities at about 4 wrenches on a 5 wrench scale. :)
 

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steve-check and make sure you have no air leaks/vacuum leaks.do you have a hunting idle?if so,and you have no air leaks/vacuum leaks,you could have a bad maf or poor connection.if your car has the ffs system,the fuel filter is in the tank.you could still have a fuel problem also.when the car stalls,does it start right back up or does it just crank than fire?
 

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HI there,
Well, there are a few ways to do an injection cleaning. Normally, per GM service guidelines, we use 2 bottles of premeasured top engine cleaner into a container of gasoline. This is pressurized, and the engine is run until it stalls. Then, it is performed again. Then there are other fuel injection cleaners that are out there, however none perform to GM standards that I have seen for correct fuel atomization and pressure drop afterwards. This is another reason why GM has us do the cleaning twice.
However, I honestly do not really believe that you would have a stalling condition from injectors, UNLESS you had water contamination of the fuel. Obviously, you would then pump water into the injectors, creating a concern.
FFS does NOT have an inline filter, this is correct.
Possibly a contaminated MAF sensor, however, I would simply check the bore of the sensor.
Do NOT, under any circumstances clean the sensor, with anything.
Allthebest, c4c5
 

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Discussion Starter #10
DPD and C4C5, thanks again. Everything seems tight and no air or vacuum leaks that I can detect. I took it out again and ran it to 120 twice, and about 10 miles of normal driving later I set two codes. This time both for bank 1 lean. I'll probably have to take it back to the dealership.
 

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Discussion Starter #11
Problem resolved!

This forum is great! I did a search and found this thread:
http://www.z06vette.com/forums/showthread.php?t=56274&highlight=MAF

I pulled everything apart and cleaned the MAF sensor with 100% IPA and a Q-tip, and reseated and tightened everything "vewy carefuwy." It was a piece of cake! I'm almost certain I had a leak where the accordian attaches to the air bridge, so I duck taped it until I can find a better solution. It looks chessy but I'll keep the hood closed in public until it's fixed. :D I did the idle relearn then took the car for a long drive and iit's performing flawlessly. I am one happy camper. I've been fighting this problem since December. This forum is great, and I take my hat off to each and every one of you for sharing your victories and failures. I had this to the dealership 3 times for this problem and they couldn't fix it. It took me about an hour with the right information. What a truly great board this is, and what a truly great group of people you are here. Thanks to everyone for your advise. :thumb: :z: :thumb:
 

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go to radio shack and ask for coaxial tape.. its a black tape and its kinda gooey.
jim hall at halltec told me to use it to seal under the couplers and tighten .. its airtight.. have not had a lean code since
 

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Discussion Starter #13
wvphoto said:
go to radio shack and ask for coaxial tape.. its a black tape and its kinda gooey.
jim hall at halltec told me to use it to seal under the couplers and tighten .. its airtight.. have not had a lean code since
Excellent idea. Thanks. :cheers:

BTW, how do you tighten that cheezy little wire clamp? I can't get it back on. Is there an alternative? Seems like a hose clamp would crush the air bridge.
 

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I know this is an older post but I wanted to say THANKS !!! I toasted my original LS6 at 110,000 miles. I got a LOW mileage (3900 miles). LS6 out of an 04 Z06. Been struggling with lean 1/2 for over a week and now have a fresh path to take. Not sure why Steve got banned but to the rest of you guys .... THANKS !!!! Hope to be rolling again soon !
 
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