Ok, So I bought a 02 Z06 this Saturday with 24k miles- drove it back home ~700 miles. Got on it on the way a little bit, car runs excellent. Great condition, etc.
Well I get back home and take my GF for a ride in it and wot at 4600 rpm + in 3rd the car stuttered a bit and I felt a little miss. It did it 3-4x before 6k and I let off and shut down. It was fairly light almost unnoticable- she couldnt even tell but I could. I thought it was weird, but I figured Id hit it and see if it did it again, and it did it again, this time she noticed it too. This time the Check Engine light also came on and soon as I let off the gas, 5 secs later, it went off.
It threw a code P03000 or something - but it was for Engine Misfire.
So I went home, grabbed my laptop, auto tap and went for a drive. Did the same thing again and although you don't feel it in 1st and 2nd gear it does it in all gears around 4600 and up under wot. This data was shown in the AutoTap log. It got a few misfires in random cylinders and also got knock retard 2x. So its not just 1 cylinder missing, it seems to be random. I think it picked it up on 4,5,6 but don't remember exactly.
Other than that, the car runs excellent. Very smooth, no hint of any misfire while getting on it a little or normal acceleration and even wot before 4500 rpm. It doesn't make sense.
Since it didnt do it when I picked up the car and on the way back I figured it could be bad gas. So I let the tank run out and have about 60 miles in this new tank of gas. Well, I ran it again after about 60 miles- ran the car hard and got no miss. But another run on the highway in 3rd gear wot, it did it again and threw the check engine light for the same code.
Im stumped on it- it could still be bad gas I guess and have effects of it in the tank, but I dunno. Maybe the car needs the plugs and wires replaced? I don't see why, it only has 24k miles.
Did the car have or does the car have any mods? That would be the first thing I would want to know. A little history would help here.
If it were me, I'd start with checking to make sure all your plug wires are secure. You should pull each wire from the plug and push back on. There should be a distinct click. Next, I would pull the plugs and have a close look at them. Pay close attention to the insulators. I had an insulator crack on mine when I installed my headers which caused mis-fire codes. If all looks fine then run a compression test on all the cylinders. Make sure the throttle body blade is wide open when you do. Compression should be around 210 psi. The next thing would be to have someone check your injectors. The procedure to check them is a little more involved so unless you have the equipment and expertise, I would let someone else check them.
That's about all I can think of at the moment.
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It's from the family Phrynosomatidae, earless, spiny, tree, side-blotched and horned lizard.
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i will pull each wire and re plug em in and see if that takes care of it. if not, the car is still under warranty, should i take it in? I know the response Im going to get - problem not found.
i will pull each wire and re plug em in and see if that takes care of it. if not, the car is still under warranty, should i take it in? I know the response Im going to get - problem not found.
If you don't mind letting the dealer work on it then take it in. Have the service writer or tech go for a ride so you can show him what you're talking about.
Im so used to working on fixing things myself, etc I was trying to problem solve and fix this as well. (Like working on cars).
But I just realized something, I actually have a warranty since this is like the first bone stock car I've had in a while!! So I took an appointment w/ the dealer that a friend of mine is the GM of and am taking it in Thurs morning. I hope I get it back that evening or Fri at the latest. I can't stand being away from it already!!
I could be so many things. U said u auto tapped it. Did you get you A/F and timing on your logs. If you are a little lean then you might be getting a little knock. This will pull timing. Might cause the car to shutter like u say. Also what kinda gas are u running like from who. What is the oct in it 91 or 93. If you realy want to know if it is timeing go to the track and by 100 unleaded and put 2-3 gallons in. If it still does it, it is not a timing or a fuel map problem. I have never felt it but i have a TA and a nice cam in it with ture duals so it is not so quit in the cab of the car.
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Justin Molina
99 Trans Am 390RWHP 417RWTQ Unlocked.
Turbo 370 in the works and on the stand.
Current mods are:
LPE 228 cam(228/228 .588/.588 114LSA) / Baskett Case Psycho Racing 2.00-1.55/LS6 Intake/Shaner2TB/Asp Crank pully/Comp timing set/Comp R Lifters/TR 7.4 pushrods/Comp 918 springs and 772 retainers/Whisper lid and K&N/FLP headers/Lanes True Duals/PT4000/3.23s/Rock On stage III race prep 4L60E/BMR SFC, TQ arm/ Baskett Case Psycho Racing LCA/TARear Girdle
Current set up Best time?
Yep. I hate taking the car in for service. It bothers me just knowing it's not in the parking lot at work.
When I travel and I get a rental car, I go through withdrawl and I almost get hives. I was in FLA a few weeks ago, and I got a Kia Alanti (or something like that) for a rental. It was mentally distressing to drive. Really bad for my "Chi". I needed an extensive set of Z06 therapy sessions when I got home again.
I too have a similar problem. I just bought a 2002 Yellow Z06 (only 14000 miles and has warranty), drove it for a week, changed the oil (Mobile 1 10W-30), and just started to have the same symptoms. The car needs to be warm (I live in Phoenix). I get a subtle stutter anywhere between 4 and 5600 RPMs, and it gets worse the harder you drive. Seems like there is a general power loss as well...kind of sluggish in overall performance anywhere in the rev range when compared to cool. I might be nuts, but I swear during these episodes I can here almost like a light vaccume noise or something in the bulkhead. I too thought that the timing was retarded from perhaps, bad gas, but I have tried several different brands of 91 oct. and the problem is persistant. I took it to Van Chevrolet, and they could not find any codes that were wrong, so they dumped it! They absolutely refused to investigate any further. Horrible experience. I am getting a second opinion from another dealer tomorrow. These kind of issues scare me because the service people try to make you feel like a jerk for getting them to look into it. I hope I get someone who actually cares at the next place. If anyone has actually found a fix, please post it. I will bring up the injector harness thing tomorrow.
What did you find out? Just bought a 2001 c5 with about 35k on it. Had oil changed two weeks ago. Same problem. Hesitation at highway speeds in excess of 65+mph- check engine comes on intermittantly; slight shudder through steering wheel at 55-65mph. Dealer looked at it in Tucson for 2 days with certified tech. Couldn't duplicate. Showd engine misfire at low rpm 200-300 and intermittant misfire at higher rpms in excess of 2500. Sent me packing too with no solution. Bought the car in Mesa but transferred with work to Douglas, Az? Were you able to find anyone in phoenix metro to help? Van chevy are not reputable from what i have heard.
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