[LITE SPD]

I am throwing no codes that I know of (atleast not any check engine light). I first noticed the car shaking upon moderate acceleration at low rpm but in a high gear. Then I tried romping on it and all the car did was misfire and backfire or pop.
So far I think I have ruled out sparkplug wires because I sprayed them with a mist of water to see spark jump and nothing. Sprayed the intake manifold and TB with brake cleaner to see a idle change and still nothing. I even tapped the MAF with the backend of a screwdriver and still no idle change. So I think my only other option would be the o2 sensors which I can't check myself or the sparkplugs themselves which are less than 2000 miles old. I also had a dynotune 2000 miles ago with a A/F that was flatlined.
Anyone with some possible options for me? What should I look for when the plugs come out? Can I tell if an o2 sensor is bad by looking at a plug? How can I tell if its the coil packs? Could this also be a valve problem or ECU problem? Thanks!

 

[LITE SPD]

Nobody has ever had this problem?

 

[Blown_Red_97z]

even though the CEL didnt light up, you might have still thrown a code. Go to Autozone and see if they will scan for codes, they usually do it for free. In most cases for the CEL to light up, the code has to be thrown in two repetative cycles. I have had misfires on my 97 that havent lit up the CEL light. Its worth a shot

 

[LITE SPD]

even though the CEL didnt light up, you might have still thrown a code. Go to Autozone and see if they will scan for codes, they usually do it for free. In most cases for the CEL to light up, the code has to be thrown in two repetative cycles. I have had misfires on my 97 that havent lit up the CEL light. Its worth a shot

Thank you for repling. Just had the car scanned and no codes at all. Now I'm just baffled!

 

[LS2GTO05]

if it is droping a cly plug ,coil,wire,fuelinj, most likly the prob 02 sensors can not make it miss

 

[LITE SPD]

if it is droping a cly plug ,coil,wire,fuelinj, most likly the prob 02 sensors can not make it miss

OK, I'm just tring to read your post. Your saying that the o2 sensor is not the problem?

 

[ShaneD_06GTO]

Should have bought a GMM... :fawkdance haha, just kidding...good luck Fiz

 

[LITE SPD]

OK, I think I fixed it. I had burnt a plug wire in the past and I thought I fixed it by wrapping it up in electrical tape. I guess that did not work too well, the end of the plug wire that connects to the coil pack had this orangy yellowish crust in it. This was way different looking than the other wires. I cleaned the bad plug wire slightly (but I will be replacing it), replaced all the plugs and then just fired her right up. Runs good now but I will be watching it closely.

 

[Blown_Red_97z]

OK, I'm just tring to read your post. Your saying that the o2 sensor is not the problem?

I dont know what that guy just said but I think he is saying that it could be either spark or fuel related, and not o2 related. I dont agree with that, bad o2's can be the devil, but really the only way to check them is to have your car hooked up to a laptop and get the readout on the o2 sensors. There is a certain perameter that the sensors need to be in, and if one bank is low, that could def. be your problem. One other thing I was just thinking about was my MAF reference wire once grounded out and that caused a lot of grief, so it could be MAF related as well. I am kind of baffled as well because I would think the car would throw a code. I guess the next step would be to hook up a fuel pressure gauge and see what the fuel is doing. If it is not in between atleast 37-45 psi under WOT, that can cause a pretty bad condition.

 

[Baaa]

OK, I think I fixed it. I had burnt a plug wire in the past and I thought I fixed it by wrapping it up in electrical tape. I guess that did not work too well, the end of the plug wire that connects to the coil pack had this orangy yellowish crust in it. This was way different looking than the other wires. I cleaned the bad plug wire slightly (but I will be replacing it), replaced all the plugs and then just fired her right up. Runs good now but I will be watching it closely.

Thats called corona and its associated with high voltage leakage. We see this alot in high voltage applications in the power industry. Our coils fire at near 100k volts. Electrical tape cannot withstand that kind of voltage and will still leak by. Just thoughts for the future!

 

[LITE SPD]

Thats called corona and its associated with high voltage leakage. We see this alot in high voltage applications in the power industry. Our coils fire at near 100k volts. Electrical tape cannot withstand that kind of voltage and will still leak by. Just thoughts for the future!

So I will probably replace the wire. I hope the coil pack did not cause this. That would suck, but I would know atleast where the problem was coming from then.
The burn on the wire was from a year ago. And it was fruther down from the boot of where the coil pack and boot connect. Do you really think it was from the damaged wire? And why did it not make that paticular plug look different from the others?