bran9669

I have a 1999 Z28 Camaro Ls1 6 speed manual. Car is running with a misfire. Codes show misfire in cylinder #6. I have replaced all spark plugs an wires. Also replaced coil pack for cylinder number 6. Replaced PCV valve an hose because the hose was severed at the rear of the engine underneath the dash.And the injector for cylinder #6 is still ticking. The motor has about 125K on it. Motor is still misfiring an code still shows misfire in cylinder number 6. Any suggestions on what this could be?

Darkman

iTrader: (2)

Well you might swap the injector on #6 with another cylinder just to make sure the misfire does not follow the injector.

Beyond that, I would pull the valve cover and check the rockers, valve springs and pushrods.

bran9669

I'm pretty sure but I just want to clarify, the valve cover gaskets are reusable right?

Darkman

iTrader: (2)

The short answer is yes.

Just be careful not to pull it out of the slot - if you stretch it, it can be next to impossible to get it back in without wrinkles.

O2Form

Is the spark plug wet? Do a quick compression test on that cylinder.

Sales2@Texas-speed

iTrader: (5)

Change the plug...see if that helps. Swap the wires from that and another cylinder, see if that moves the miss. Then swap the coil from that to another cylinder, see if that moves the miss. Then Swap injector and see if that moves the miss. Only do one at a time though, or it might move and you won't know what did it. If the problem moves with the part you swapped, then you've found the problem part. I'd say more often than not, it is one of those parts causing a misfire on a single cylinder.

bran9669

I am about to pull the plug. I will try swapping those things one by one an will let you know the results. What my fear is someone told me I may have melted a piston a while back. I suppose a compression test might tell me if thats the case. I am about to get to work an will keep you posted. Thank you for your input. All of it is greatly appreciated

Darkman

iTrader: (2)

My reading of your first post was that you had already eliminated plugs, wires, and coils as possible causes. Whether the plug is wet would be nice to know. If the compresssion is low in that cylinder the cause could still be underneath the valver cover.

FBodyPerformer

iTrader: (19)

Just got done dealing with a misfire on my #6 cylinder. Long story short, I pulled the engine yesterday

bran9669

Okay, I switched the plug (which i was sure was fouled out but still managed to fire in another cylinder) and the wire from number #6 over to #5 (only because #5 is one of the easier ones to get at) Did not eliminate the misfire in #6 but the motor most definitely ran more smoothly than before. Though the misfire stayed in #6. Also a new 2nd code popped up for the pre-cat 02 sensor on the passenger side. I have been doing some reading an have learned a little more. Today I am going to try swapping injectors an the coil ( even though the coil on #6 is new). I have also herd the misfire could be caused my clogged cats (car had 125k an im pretty sure the original cats), or a malfunctioning mass air flow sensor. I'm assuming if i just hollowed out the cat it would still throw a error code???? My financial resources are non existent at the moment so I'm trying to get creative. I also don't know of anyone I could borrow their Mass Air Flow Sensor to test my own. I still hold hopes of it still being a fairly easy fix though have feared much worse for a long time. This all started over a year ago. I was driving, on it pretty hard, towards the top end of 2nd gear in a drift when i realized I had forgotten the gas light had been on. As soon as I let of an headed for the nearest gas station I could feel the whole car shaking from the miss. It never ran out of gas but I'm sure it was pretty close. I filled up an hoped it would disappear. It didn't and It was not my only car at the time so I parked to an tried to troubleshoot when I could with very little knowledge to help me. Found the PCV valve hose in bad shape around the pcv valve. A friend with a T/A rigged something up for me. then it sat for longer. Next I did the spark plugs an wires an #6 coil. Sat for longer. Then it became my only vehicle so i had to drive it. I found the PCV valve hose was also almost severed on the back side of the motor. I rigged that as best i could. an drove as little as possible. Then in march I was pulled over leaving work and the car ended up in the custody of the city police where it sat for 9 months. I just got it back. bought a new PCV valve/ hose and need a running car to get to work. Sorry for the unnecessarily long post but thats the complete history. I have a few things to check today. Will keep you posted an probably will have a few questions later today.

eseibel67

iTrader: (10)

You can get better advice if you tell the whole story from the beginning. The fact that the problem started during those conditions is worrysome. I would skip the normal troubleshooting as per Matt's instructions, and go straight to Darkman's advice: Check compression.

havoc04

iTrader: (1)

Hey i had a mis on 5. did all the switch a roo things and did a copression check finally. 90 on 5 160 on 3. got apart and have a broken piston. do a compression check

AAK z28

iTrader: (18)

possibly a popped head gasket between cylinders