Engine stumbling - compression test

[AKSockeye]

Went off-roading a few weeks back and the engine hasn’t been running well since. Engine stumbles pretty bad up around 2000 rpms and idles slightly rough. Seems like a got into some puddles high enough that the fan sprayed the whole engine bay with silty water. I pulled the plugs and did a compression test. The results are in the photos as well as the pics of the Spark plugs. Spark plugs 1-5 had white build up on them, sp6 was more normal looking but was missing some metal off the very bottom. Also got a cyl6 misfire code the same day as off-roading but after clearing it it hasn’t thrown that same code again. I think this means I’m running hot in general, but what can I do to fix it?

 

[izzymonkey]

Get new spark plugs. Motors not running hot. Plugs are just wore out.

 

[Malleus]

You didn't state which engine you have, so here's the information for the 1FZ-FE:

You're near the limit at 1/2 and 5/6. You need to supply more information about the general state of the engine to get any pertinent recommendations. For example, how much oil are you using per x-miles? Is it smoking (at idle, under normal driving conditions, under load)? Have you noticed a general worsening of performance over time, or during a relatively short period of time? Any of this data, and as much more as you can provide (refer to the FSM, engine troubleshooting section) will be helpful.

I wouldn't listen to anyone who said he knows what is wrong and what to do about it, without more information than you've provided.

The plugs look fine to me, from what I can see in your photos. Ideally, you should have a light grayish-white powder on the electrode.

 

[Malleus]

Since you mention you went wading, I'd suggest you pull the distributor cap and clean the inside, the rotor and the gasket. I'd also use some CRC plastic safe contact cleaner to blow out the coil and plug wires, as well as the coil contact. Grease them with dielectric (I use Permatex, but anything is better than nothing); it'll protect the electrical connections for your next water adventure.

 

[Tools R Us]

Went off-roading a few weeks back and the engine hasn’t been running well since. Engine stumbles pretty bad up around 2000 rpms and idles slightly rough. Seems like a got into some puddles high enough that the fan sprayed the whole engine bay with silty water.

The TPS connector is not weather sealed, is prone to getting moisture in it and can cause poor running in that range. We clean them out and apply some silicone grease, reducing future problems. Have seen this without setting a code. Also, confirm that your air intake tube is good, not cracked.

... Also got a cyl6 misfire code the same day as off-roading but after clearing it it hasn’t thrown that same code again. ...

Common, #6 is lowest on the distributor, so most often to have a moisture miss. Depending on the year, most of the distributors have a breather hole near the connector, prone to splash leakage. On those, sealing that hole with a dab of RTV improves the deal.