Hesitation/Popping
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Racer
Joined: Jan 2005
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From: Fort Lauderdale/Miami FL
Hesitation/Popping
To summarize, I have an '01 M6 Coupe w/ 30k miles. Just a few days ago, I did the de-carb procedure with GM Top Engine Cleaner. When I started it the next day (10 hours later), it stumbled & puffed smoke, as expected.. & then I immediately brought it to the dealer to have the oil & filter changed, along with new plugs, new diff oil, & a new tranny oil. Ever since then, I've noticed a reduction in power/hesitation when WOT in almost any gear as the revs climb. Basically.. when I floor it, power comes on, then hesitates for a second or two, then builds full power again. This has been getting progressively worse over the past few days.. & is occuring more often, accompanied now by a popping/backfiring noise. I have the car scheduled to be at the dealer this Monday to get a TechII hooked up to the car & see what's going on. What do you all think? The new plugs in there are NGK TR55's. Are the cats really clogged? Timing/kR issues? Anyone have a similar problem like this before? Lemme know, thanks in advance.
- Matt
- Matt
Team Owner
Joined: Oct 2001
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From: Boynton Beach Florida
St. Jude Donor '07-'12, '20
Loose or broken plug wires, loose or cracked plug. Matt I would check these items first. If you want to drive to Boynton Beach, I will be home around noon tomorrow and I can look at it. 
Bob
Bob
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Racer
Joined: Jan 2005
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From: Fort Lauderdale/Miami FL
Originally Posted by 16Again
Loose or broken plug wires, loose or cracked plug. Matt I would check these items first. If you want to drive to Boynton Beach, I will be home around noon tomorrow and I can look at it.
Bob
Bob
- Matt
PS - Others are still encouraged to provide any suggestions/feedback.
Melting Slicks
Joined: Jan 2003
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Originally Posted by 12stepvette
Have the O2 sensors Checked...They don`t react well to harmful fuel additives, carburetor Cleaner or other harsh chemicals.
Tech Contributor
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Sounds to me like the technician damaged one or more of your sparkplug wires. I would remove them one at a time check them with an ohm meter. Each (OEM) plug should read 250 - 700 ohms. Check the wires and boots for burns, cracks and rips. Make sure that all of the wires ar properly connected to the coils and sparkplugs.
I use silicone lubricant on the boots.
Here is what I found after I had someone work on my car!!
I had a real bad miss and poping under hard acceleration!!
I could hear the arching when the engine was running!
Bill Curlee
I use silicone lubricant on the boots.
Here is what I found after I had someone work on my car!!
I had a real bad miss and poping under hard acceleration!!
I could hear the arching when the engine was running!
Bill Curlee
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Team Owner
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From: Boynton Beach Florida
St. Jude Donor '07-'12, '20
Bill I thought the same thing. Matt just left here, I found 2 badly broken wires and 1 with a small tear in the boot. I changed out the wires (old set from my car) He just called me and still has the same symptems. Under hard acceleration at roughly 4500 it's as if it has backfiring. I only pulled one plug and made sure all the others were tight, I don't see anything obvious. I thought for sure those broken wires were his problem. I'm stumped...........
Bob
Bob
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Racer
Joined: Jan 2005
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From: Fort Lauderdale/Miami FL
First off, a personal thanks to Bob for extending the courtesy to look at my car, free of charge at that! There were indeed 2 extremely mangled wires that were replaced with Bob's old set. The car seems slightly better. From the few runs I got with the car, I noticed it doesn't happen as much around the street as it does at higher speed (i.e. - the highway.) I really don't know what the deal is. Some folks mentioned O2 sensors, fuel filter, spark plugs/wires. Maybe all the plugs need to be checked? Stumped as well.
- Matt
- Matt
Tech Contributor
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Matt
An O2 sensor would set a code. This is what I recommend. Since the last place anybody had their hands was the sparkplugs (tune-up), as much of a pain in the A$$ as it is, remove and check each on of the sparkplugs and maybe throw on a new set of wires. Look for proper gap, cracked.damaged insulators ect
It sounds too much like a misfire than a problem with one of the other engine componets. Do this test. When the problem occurs, take a look at the check engine light. If it comes on as the problem occurs and then it goes off, it's indicating a mis-fire. When the light is on you will be able to pull up a PCM -0300 DTC code. When the light goes out, the code will go away. If the check engine light stays light, the P 0300 code will remain in memory.
Before you get too deep into replacing expensive stuff, run this one into the ground first.
Bill
An O2 sensor would set a code. This is what I recommend. Since the last place anybody had their hands was the sparkplugs (tune-up), as much of a pain in the A$$ as it is, remove and check each on of the sparkplugs and maybe throw on a new set of wires. Look for proper gap, cracked.damaged insulators ect
It sounds too much like a misfire than a problem with one of the other engine componets. Do this test. When the problem occurs, take a look at the check engine light. If it comes on as the problem occurs and then it goes off, it's indicating a mis-fire. When the light is on you will be able to pull up a PCM -0300 DTC code. When the light goes out, the code will go away. If the check engine light stays light, the P 0300 code will remain in memory.
Before you get too deep into replacing expensive stuff, run this one into the ground first.
Bill
Thread Starter
Racer
Joined: Jan 2005
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From: Fort Lauderdale/Miami FL
Bill, I was thinking the samething. Based on your pictures, both the wire AND plug were bad.. so who's to say my technician didn't cover all the angles as well? 
Anyway, I shot a PM over to Bob to see what he thought. I really hope it's only a plug/wire related problem, as going from component to component isn't exactly what I had in mind, nor should I have to do that. For the record, Kelley Chevrolet in Hollywood, FL are the ones who worked on my car. For a dealership that has their own self-proclaimed "Corvette Performance Center," I find it interesting that one of their techs couldn't handle a simple plug job. Did I mention that when I received the invoice, the tech noted that he had to replace (and subsequently charge me for) a plug wire that "came apart" as he was doing the plug change.
- Matt
Anyway, I shot a PM over to Bob to see what he thought. I really hope it's only a plug/wire related problem, as going from component to component isn't exactly what I had in mind, nor should I have to do that. For the record, Kelley Chevrolet in Hollywood, FL are the ones who worked on my car. For a dealership that has their own self-proclaimed "Corvette Performance Center," I find it interesting that one of their techs couldn't handle a simple plug job. Did I mention that when I received the invoice, the tech noted that he had to replace (and subsequently charge me for) a plug wire that "came apart" as he was doing the plug change.- Matt
Drifting
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From: Yakima WA
Just curious as to why you changed plugs, etc?
I just recently bought my 01 vette w/25k on it. I thought plugs didn't need replacing until 100k? I thought it was longer to diff. fluid, etc. too? Why did you decide to do these changes w/only 30k on the ticker? Was it a mod? changing plugs?
Thread Starter
Racer
Joined: Jan 2005
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From: Fort Lauderdale/Miami FL
Originally Posted by dbwade36
I just recently bought my 01 vette w/25k on it. I thought plugs didn't need replacing until 100k? I thought it was longer to diff. fluid, etc. too? Why did you decide to do these changes w/only 30k on the ticker? Was it a mod? changing plugs?
) As for the plugs, I was not sure when the last time they were last replaced, so I had them done. A lot of Vette owners I know use the TR55's & love them. You are correct however, the diff & tranny oil don't need to be replaced at 30k. Again, just peace of mind on my part. - Matt
Tech Contributor
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
I changed my tranny fluid at 18,000 and it was dirty. It looked darker than it should have been! The new Synthitic ATF made things A LOT better! Shifts MUCH smoother!
I will do the rearend fluid in the spring. She will have 22,000 on it. I will do it to get some synthetic fluid in there!
BC
Shifts MUCH smoother! I will do the rearend fluid in the spring. She will have 22,000 on it. I will do it to get some synthetic fluid in there!
BC
Melting Slicks
Joined: Jan 2003
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Originally Posted by imagine32000
I am the second owner of my Vette. Based on service reports I've looked over on the car with the previous owner.. it looks like he took fairly good care of it. Anytime I purchase a vehicle, I have all the basic (and then some) maintenance completed for peace of mind. I'm also a fan of Red Line oil/fluid products, as I've heard nothing but good things about them. My transmission shifts noticeably better, the diff is the same (no whining/grinding noises), and I thought a switch to 10W would possibly help guard against oil consumption (that.. and I live in South FL (i.e. - no holy crap cold starts ) As for the plugs, I was not sure when the last time they were last replaced, so I had them done. A lot of Vette owners I know use the TR55's & love them. You are correct however, the diff & tranny oil don't need to be replaced at 30k. Again, just peace of mind on my part.
- Matt
) As for the plugs, I was not sure when the last time they were last replaced, so I had them done. A lot of Vette owners I know use the TR55's & love them. You are correct however, the diff & tranny oil don't need to be replaced at 30k. Again, just peace of mind on my part. - Matt
If you have the choice, I'd find a Corvette tuner near you rather than GM.
Best of luck to you.
Team Owner
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From: Boynton Beach Florida
St. Jude Donor '07-'12, '20
Matt I answered your PM. C'mon over and we'll pull all the plugs (after the car cools down) Boy that thing was hot! I don't know any speed shops that are open on Sunday but if you do, pick-up a set of MSD wires or something else of your choosing. Can't hurt to put brand new ones on. What I put on today only had about 12,000 miles on them. Hey Bill any chance he may have a bad coil?
Boy that thing was hot! I don't know any speed shops that are open on Sunday but if you do, pick-up a set of MSD wires or something else of your choosing. Can't hurt to put brand new ones on. What I put on today only had about 12,000 miles on them. Hey Bill any chance he may have a bad coil?
Tech Contributor
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From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
I personaly have not see a C5 coil go bad but anything is possible.
Here is a couple of things to check. There is a fuel rail support on the drivers side fuel rail that can cut the engine wiring harness. Look at the rear fuel rail support. You will see the wiring harness around it. On some C5's the harness is short and that support cuts the wires. Your fuel injector wires and coil wires are in there!
Give that a look see!
BC
Here is a couple of things to check. There is a fuel rail support on the drivers side fuel rail that can cut the engine wiring harness. Look at the rear fuel rail support. You will see the wiring harness around it. On some C5's the harness is short and that support cuts the wires. Your fuel injector wires and coil wires are in there!
Give that a look see!
BC