turboguard

Long story short, I'm pretty sure I've been driving around with my #7 cylinder not firing. So my starter finally completely cracked open due to the PO not shimming it properly, and I was checking things out under my car when I noticed that the #7 plug wire boot wasn't fully seated onto the plug (to where it snaps into place). I have been experiencing some rough idling, surging when warmed up, and some power loss at WOT (although I'm pretty sure my quadrajet could also use a rebuild).

I pulled the plug and it looked pretty fouled. I decided to just pull all the plugs as well and they were all fouled up to some extent. I'm not exactly sure how old they are since the PO claims it had a fresh tune up recently with MSD ignition parts. I took off the cap and rotor and they looked to be in pretty good shape, not too much buildup on the contacts. The top of the distributor looked pretty good as well (I'm fairly certain its the stock distributor). I bought some new ACDelco plugs and put everything back together. I also replaced the O2 sensor, both coolant temp sensors, the knock sensor, and did an oil change and coolant flush while I was at it.

My big concern is...how much damage did driving around with one cylinder not firing do? Is the cylinder already toast? I would estimate from the time I bought it I've put approx. 800 miles on it. I haven't had a chance to actually drive it around since I've done all the maintenance on it, but I did start it up. It still seems to have a rough idle, and a noticeable ticking sound coming from what I believe is the driver's side valve train.

I really didn't expect to have to do so much to this car when I bought it, but to be honest this is my first car I've decided to do all the work on myself and I AM enjoying it immensely, but I just can't afford really HUGE problems right now...

sofakingdom

iTrader: (1)

Most of the damage was to your wallet, in the form of increased fuel consumption.

Didn't hurt the motor at all.

Adjust the valves. Good chance that'll take care of it.

turboguard

Thanks for the reassurance, most of this stuff is still pretty new to me, but I'm learning pretty fast thanks to this forum, youtube, and the massive 1800 page service manual I bought.

86LG4Bird

iTrader: (1)

So, you don't subscribe to the popular notion that the accumulated fuel washes the lubrication out of the cylinder bore surface and accelerates bore and ring wear?
I hope you're right, because I just discovered one of my kids was driving around with a dangling plug wire....... told me she didn't think the car was getting enough gas.....lol!

paulo57509

Catalytic converters don't like raw fuel going through them. This isn't a concern if you don't have to pass any kind of emission sniff test.

turboguard

Luckily I don't even have a cat

sofakingdom

iTrader: (1)

I do; but if the cyl isn't firing, then there's basically no load on anything, and nothing gets hot, and fuel isn't burning between the rings and the bores or in the ring lands or all over the piston skirts, so nothing gets hurt. Especially not if it only goes on for a relatively short time.

Now, pouring excessive fuel into a RUNNING cylinder, ... much worse.

86LG4Bird

iTrader: (1)

She went no more than ~100 miles with the wire off, and based on no statistical difference in cranking compression reading on that cylinder compared to others, I'm gonna say you're right