I have a 1994 Toyota 4runner v6 and I just found out what cylinder is bad. Unfortunately I'll have to run with the knock problem for a while longer. It's completely dead and only knocks, nothing more. Whats the best way to plug the cylinder so that it doesn't use fuel without further damaging my engine more than it already is?

 

There is no 'best way', but to stop operating it until it is repaired.

Anything else will likely cause further harm.

I guess that you could unplug the offending cylinders' fuel injector to keep it from supplying fuel.

But, what does 'dead' mean to you???

Is the cylinder dead because it has no spark?

Is it dead because it has no compression?

Is it dead because it is already receiving no fuel?

What does 'knocking mean?? This usually implies mechanical fault.

What diagnosis has been done to establish what is trul;y wrong??

 

Well I've been running with this rod knock for years now but I kinda ignored it. I was thinking about unplugging the injector. I tested all cylinders by cutting each cylinder off individually. #2 did not change the engine idle at all and when disconnected the rod knock is gone. I just need to run it for a bit longer until I do the 3.4 swap.

 

Unless you disconnected the piston not much else will make a rod knock go away.

Sounds like you have something else going on.

Then a few may have a rod knock for a few years although most just get worse to the point things come apart .

Most times stopping rather abruptly in the worse possible spot

 

Wyoming is spot on, rod knock does not go away by pulling the plug wire, something else has to be going on. Ohm the injector on that cylinder, screen in injector clogged, bad sparkplug, bad trace in distributer cap leading to that cylinder, bad spark plug wire, are some of the things I would check first.

 

How did you cut the cylinder off? Rod knock does not simply go away by disconnecting a spark plug or injector. Think about it for a second. The motor is still turning and that cylinder is still under load regardless. #2 is one of the better cylinders to get to and you should do a compression test and really see how it's doing. If you are content trying to run it on 5 cylinders ( I do not recomend this) then at least try to disconnect the injector to keep from washing out the cylinder.

once again this could be a miner issue.

 

Rod knock is a symptom of the bearing between the connecting rod and the crankshaft being out of tolerance. It will get worse and worse until you wipe or spin the bearing, seizing the rod, and causing catastrophic failure i.e. rod through the side of the block.

Piston slap has a similar sound and is s result of an out of tolerance wrist pin or cylinder bore.

If your noise goes away when you disconnect the injector. You are taking the load out of that cylinder and taking most of the stress off of those parts. You could take the spark plug out and unplug the injector and run as a 5 cylinder motor.

That is going to cause a miss from that cylinder and probably some oil consumption. But it will take most of the strain off your damaged internals.

Whatever you do, keep in mind, they all end in catastrophic engine failure.

 

I wonder what running a "dead cylinder" on a 3vze would do as far as AFR and the knock sensor will probably be pulling timing like crazy on a motor that is already down 25hp. Ready for geo metro acceleration with Big block Cadillac MPG?

 

I suggest (as everyone else did) park it til u can properly repair it or risk it costing you MUCH more in the long run.

but to answer your question disconnect spark plug wire and injector to relieve some stress. And maybe consider running an oil additive like Lucas oil stabilizer or similar, I like the Lucas stuff cause it's very thick and really helps "cushion" stuff and make it run quieter. But there's several products that do the same I just have used this stuff myself and really helped. Although I was just looking to help the valve noise on an old 7.3 diesel, a rod knock is a whole nother issue.

good luck!