Hi everyone...

I am posting because I am in dire need to assistance. I replaced my spark plugs and wires in my 1997 corvette and after finishing the installation, it is running like crap. It idles fine when in Park, or Nuetral, but when I put it in any gear it idles very rough...

I have went through and checked the wires where they connect to the coil pack, and also to the plug; they seem to be on fine. Any idea's???

The car was running fine before I decided to change them out, I just thought it might help it, but seems it done the opposite. I know it doesn't make sense, the car should run better with new plugs and wires, but I can't determine where my problem might be. While driving it, the check engine light did come on. Then I came home, disconnected the battery and rechecked the wires, connected the battery back and the check engine light hasn't came on yet...

Please help me... Thanks in advance!

~Chris

 

What code did it set, did you check the plug gap and whos wires did you use?

 

Did you hear a distincitve "click" on both the coil and plug side of the wire? I would check them again. If that is OK, pull the plugs and made sure none of them are cracked.

Did you unplug anything else like a vacuum line or electrical connector to gain access to some of the tougher to reach plugs?

 

I used the DuraLast wires and Autolite Platinium plugs; they said to gap them to .50, so that's what I done...

This morning I took the wires off again and with a sandpaper sanded the connector of the spark plug, it seemed to help, but still, something is not right.

The only tube I removed is the one that goes to the master cylinder and I connected it back after I was done. That's all I disconnected, unless something else accidentally. Thanks for the help guys...

~Chris

Oh as for the code, I wasn't aware until later that you could check your own codes on the vette, so I didn't. I disconnected the battery and played with the wires, it cleared it and the check engine light has not turned on yet.

It has to be a cylinder misfire, because I can smell gasoline at the exhaust tips... Comments???

 

There is a ground near the back of the driver's head, make sure the cable is OK and still attached. There is a temp sensor on the driver's head between #1 and #3, make sure that it plugged in as well. I would also measure the resistance of all the spark plug wires and make sure one of them wasn't bad out of the box.

I'm running out of ideas, other then to install the old parts and see if the problem goes away. Kind of a pain though.

 

After driving a bit, I got the codes P0141 (Oxygen Sensor) and P0300 (Cylinder Misfire).

I came home, pulled the plugs again, opened the gap to .57 and visually inpected them; they looked fine. So I put them back and put the wires back.

Car is still running like crap, this is frusturating... What the guy at AutoZone told me is that maybe a oxygen sensor went bad when I replaced the plugs because it was used to the old plugs... Do this sound likely?

This sure sux, the oxygen sensors are $50 a piece... They said its the 2nd sensor in Bank 1... Anyone know which one that is??? I'd hate to replace them both and spend $100 needlessly...

When you say the temp sensor between the #1 and #3 cylinders, is that the aluminum tube that connects to a rubber hose? If so, then it's connected. I haven't been able to find anything out of the ordinary...

Thanks for the help guys, I think you all are the only ones keeping me from going insane!!!

~Chris

 

My advice: I just did this too, and I had a similar problem. The wires really need to "click" when they go on like was mentioned above. My rough idle was exactly this. I thought the wires were on, but a few were not quite clicked on.

 

Didn't drop any of the plugs when you put them in did you? If the ceramic part is cracked on any they may be grounding out. Also make sure you wires are not laying on the exhaust or each other and cross firing... something stupid but it can happen.

 

Alright, now I am stunned... I freakin went to AutoZone, bought an O2 sensor, replaced it ($55, not to mentioned burn my arm)...

But the P0141 code does not clear, I disconnected the battery and it is still there... The car is still running like crap, very, very bad! I should have never messed with it!!!

I'm at the end of my rope, I don't know what else to try...

New plugs/wires, O2 sensor and it still runs worse than it did with the equipment it came with in 1997... Boy do I regret ever messin with this damn car... I've changed plugs and coil packs before, but NEVER, NEVER have I had this hard of time... This sux...

~Chris

Sorry, but I need to vent somewhere and unfortunately this is where...

 

Chris

Calm down. We will get this thing figured out, Grab a cup of your favorite beverage and lets get started!!

The very first thing that you need to do is (like previously stated) make sure that the coil boots and plug boots are on correctly and that the metal coil tip and spark plug tip are properly mated.

I had an intermittent mis after my header install. This is what I found was the root cause:



It is possible that one of the insulators is cracked right at the plug body/porcelain mating area and allowing the voltage to ground out.
My guess is that a plug is at fault.


You should be able to tell which plug is not firing by removing them and looking at the tip and insulator. The one not firing will wet and fouled.

One trick that I use to get the coil boot to seat properly is to insert the flat end of a very small tie wrap in the boot, insert the boot on the coil tower and when the boot is snapped on to the tower pull up on the tie wrap and burp the trapped air out. Once the air is out, pull the tie wrap out!

The reason you seeing P0141 (Oxygen Sensor) DTC codes is the raw fuel being pumped into the CAT because of the P0300 (Cylinder Misfire).

You can zero in on bank 1 which is the LEFT side as having the faulty component. You could also disconnect one spark plug wire at a time on that side and see which plug wire removal doesn't effect the engine idle and RPM as much as the other ones. IE... If you remove and then replace the wire off cyl# 2 and the rpm drops down to 400 rpm while the wire is removed, and then remove the wire from cyl#4 and the RPM stays about the same, cyl #4 is at fault!

Give that a try and let us know how you make out.

BC

 

And, don't listen to anyone at Autozone.

 

I would try switching out spark plug wires one at a time. New vs old. It sounds like bad wires. A very weak spark will give a nice idle and then run crappy under any load.

 

Although it may be unrelated take a look at your coolant sensor. Will cause similar symptons

 

My manual calls for a 41-938 plug at .060 gap. As a side note,all the platinum plugs I have bought came pregapped as they are easily damaged. Autozone told me the same thing about gapping the plugs,but the package said "pregapped for each application-do not adjust gap". Might be your problem. Chuck.

 

Bill-
You are the man! I went one by one and unpluged the wires like you suggested, I found that plug #3 and #8 both had the insulator cracked. On #3, you can't even tell, but when you try moving the insulator you can feel it. As for #8, it is slightly cracked at the bottom and the insulator moves.

As for AutoZone, I think these plugs came defective and I didn't notice when I installed them. I will see if they can replace them for me. And yes, I regapped the plugs to .57 rather than .50; was it necessary to replace the O2 sensor? That alone costed $55, I wonder if AutoZone will take it back and give me my money.

Anyhow, thanks alot to everyone for your input. It helped me out greatly!!! Thanks again!

~Chris

Happy Holidays!!!

 

Merry Christmas! Thats my stocking stuffer for you! Dont let this small problem discourage you from working on your car!!!! Post your problems here and we will get you through them and fixed PROPERLY!

BC

 

So how's she running? Any lessons learned? R/ Al

 

Just a word of caution.

A friends brother of my sons has frequently tuned up his cars and takes the used parts back in the original new boxes and returned them as not needed. Im sure they resold them also to unsuspecting people. I check all my parts very carefully after I buy them and have on occasion noticed they have been installed and taken back off or even been used.

 

A while back I was going to purchase one of the Fram "Air Hog" air filters for my VW GTI. They are frams answer to K&Ns filter and cost less. I wanter to see what the filter looked like and opened the box. GUESS WHAT????? Some jerk put a regular Fram filter in that box and purchased the Air Hog in the regular box for the regular filter price!

I brought it to the managers attention and he said "Yea it happens all the time! Didn't seemed too concerned!

Man I would have been PISSED if I got home with that regular filter!!!!!Probably wouldn't have gotten any resolve from PEP BOYS either! They would have thought I was trying to pull off a scam.

Yea,,,I check new parts carefully also!

BC

 

Spark plugs are like eggs. Someone probably dropped the whole box of plugs at Autozone, or there was too much side load on the socket when installing.