What's this spark plug telling me?

Do the compression test on a cold engine. Do not put the spark plugs back in. Use a vacuum and clean out the tubes if you can. If not, then put the plugs back in and use compressed air. Pulling the relay is a yes. By the way when you’re done with everything, your check engine light may be on because of components being disconnected. Don’t be alarmed. Disconnect your battery ground cable for 10 minutes and it should reset the computer. If after everything is put back together and running a day or two and the light comes back on, there may be an issue where you need to have it checked out for a code to point in the direction of where to find the problem. A computer code does not tell you what component is bad but gives a condition problem that has to be diagnosed.

 

Ok. Good. The compression tester reads to warm the engine first.
I think my cel is messed up anyway. As far back as I can recall, besides a misfire code once, it' s been o2 sensor, o2 sensor.... I have burned through 3 evap vsv's in the past few years. I have one now that's messed up & no code.
Anyway, another question - while I was experiencing some of these idle type symptoms prior to the spark plug change, could this fuel/oil be due to improperly torqued plugs?

 

I don't think so. The plugs themselves don't look too bad so it may just be a leaky valve cover gasket or spark plug seals. Hopefully, it's one of those things.

I dunno how the first-gen works, but most cars have an upstream and downstream O2 sensor. Usually, the upstream commands the fuel trim during closed-loop operation. A failing upstream o2 sensor could easily cause your idling issues.

Edit: The reason I don't think it's a seating issue is that usually the insulators on the plugs will get discolored by the exhaust gasses, while his look fairly clean.

 

A warm engine is better but you have everything pulled apart already. A cold engine will give you a different compression than a warm engine but should be enough information in the results to give you a good idea how the engine is. Loose or not seated spark plugs could definitely give the gas smell and possibly some oil.. I would do the compression test and write down what the compression is for each cylinder. Install the spark plugs and make sure that they are tightened correctly. Clean any oil or gas on the spark plug wires and coil wires. Put everything back together correctly. Disconnect the negative battery cable for 10 minutes and reinstall. Let it run several minutes until it warms up to normal operating temperature. If everything seems OK drive it for a little bit and see if the check engine light comes on. If it does, have someone scan the computer for what codes come up and proceed from there.

 

ok. Guess I best find my 3/8 torque wrench. I only had the 1/2 so figured I'd "eyeball" it. I've been wanting to do a compression test for a while now, so this'll get that happening. I was not prepared to do the gaskets. I have been down for some time with re-replacing leaf springs, the ps pump & getting the IAC freed up. The truck needs to get out & "stretch its legs". Thank you. I'll report back....

 

After you resolve what most likely is a valve cover gasket, clean the throttle body....BOTH Sides, and consider a fuel injector cleaning by a 3rd party garage (BF products @$125)......
Did all the above, every little step improved it, all together I have a new truck......
215K....

 

& that's meant to be a thank you to everyone for their input.

 

Ok. & I got the throttle body really good n clean this time, but certainly can't hurt to do it again.

 

It's telling you why did you take me out?
I'm good for at least another 20,000 miles and I'm running clean as a whistle.

 

Just saw this.
The o2 sensor, o2 sensor reference was because it seems that any time the cel was on that'd be the code. The light has not been on for a while, although I think it should be, if for nothing else than the evap vsv.
& yes, the 1st gen has two the o2 & the a/f sensors.
I'll gear up for the gaskets.

 

Just occurred to me - as I was reading about doing said compression test, there was a way to do a wet compression test on a cylinder which did not "pass" the dry test. The end result being that you could possibly hear the leak. I think it was described as a kind of hiss. Is this something I could say, hear without doing the test? I started hearing a hiss type noise, almost like a vacuum leak. It was/is coming from behind the throttle body. Number 5 vicinity? I have been unable to locate the source, obviously. I state this though, because I have checked for vacuum leaks & have found none. New hoses all around. Manifold vacuum test....

 

Hissing sound could’ve been coming from spark plugs number five if it wasn’t seated down correctly.

 

The wet cylinder compression test is done if your compression is low in one or more cylinders. The wet cylinder compression test is when you take a half a teaspoon of oil and pour it into the cylinder through the spark plug hole - wait a few minutes and retake the compression test. If the compression raises it’s typically a piston ring issue. If it does not raise up it is typically a valve issue. Worry about a wet test if it does not pass the regular compression test. The object is to get it tested, put back together and running. At that point you can properly diagnose any other issues. Remember you do not want to do too many things at once to try to find a problem. If you still hear the hissing after everything is put back together, you can go diagnose the problem at that time. Also on some vehicles the screws for the IAC valve may have some Loctite on the threads. If you put a small amount of heat on the screw head for a short period of time, it should melt the Loctite and make the screw removal easier. This can be done with a small pinpoint butane torch. Just heat the head of the screw and don’t melt anything around it.

 

I haven’t gotten to the compression test yet, but here are 2, 4 & 6
Definitely more of a fuel smell on this side. All of the boots smell, but the strongest is 6, if that has any significance.
Curious as to why the porcelain half smells stronger. Is that typical or does it just mean that it may only be leaking in the valve area & not in the manifold?
Whatever happened was over the past couple of months. Things I can think of that I did fuel wise was put in a new pump, change out the hose from the canister & recook up the fuel pump regulator hose which I managed to miss back when I did the valve cover gaskets.
I thought the fuel pressure test I did last week was showing I needed a regulator, but when I posted the results on here I was assured all was good.

Ok. Off to do the compression test.

 

If you have a leaky valve cover gasket, the oil will seep from the top of the sparkplugs down. Since half of the sparkplug is inside the engine and the other 1/4 is covered by the boot (COP, I don't know what 1st gens use), it will accumulate on the bottom portion of the plug, hence the smell on one side. I have my doubts that a leaking valve cover would cause these issues (totally possible, I just don't think that's the issue), as the OP has removed/replaced/reinstalled the plugs multiple times and I assume that the problem continued directly after doing so.

If you can smell gas after the engine has been shut off, it could also be a stuck injector. How does your oil smell? Can you light it with a flame? Is it overfilled?

 

compression test
remember this is a first for me. I tried to read it as accurately as possible - my understanding being that you try & get the highest reading. A little hard to do while it's in motion.
1-184
2-190
3-150 It seemed as though 4 cranks was needed to get the highest, since I had only done 3 the 1st time I went back & redid 1, 3 & 5 - 3 came in at 120 the other two were about the same
4-160
5-184
6-190

 

Maybe I am misunderstanding you, however somewhere in all these posts (understandable if you missed it) I explained that the plugs I removed a couple of months ago were not like this. That is why in my previous post I stated that whatever is going on has transpired or hit the point of revealing itself through the plugs within the past two months. & I'm not sure about your reference to the multiple spark plug change? It had been a good year or so since the one I did a couple of months ago. That's it. & this is the first time I have removed them since.

I do not smell gas after I shut the engine off.
My oil is not overfilled.
& I just went & checked & yes. my oil does smell like fuel.

 

Sorry, I'm on mobile, so it is more difficult to express what I am thinking into words When you previously removed the sparkplugs, did the rough idle condition go away? If not- the problem is most likely not the valve cover gasket as the plugs would have been clean for a short time.

The compression in cylinders 3 & 4 looks bad. All cylinders should have no less than 10% difference in compression. You do not read the gauge when it's in motion. You crank until the gauge maxes out, stop cranking, then read the gauge. IMO it does not matter if you do 10 cranks or 5, as long as you get a good reading.

Did you do a dry and wet test? Usually, you do a dry test on all cylinders (sounds like what you did), followed by adding a cap of oil into each cylinder (wet test). A wet test may tell you what is causing the lower compression on cylinders 3 & 4; if compression goes up after adding the cap of oil, your piston rings are toast.

 

One thing on the compression test I apologize for not mentioning. They all dropped after cranking was done. I was a little unclear as to whether it was the highest reading or the highest resting place. I tend to take things like instructions, very literal & they stated "highest reading". However, being that instructions can vary, as well as interpretations & vehicles here are the highest resting readings.
1-172
2-179
3-142, then 110
4-152
5-170
6-170

 

I hear you on the expressing.... All good....

Funny you mention that - I remember saying "smooth like buttah" right after I changed them, so while I couldn't necessarily say how long it was before the rough idle returned, there was definitely a happy period of time right after.

Ok. Good to know on the gauge. I should have asked.

I did not do a wet test. I was advised by another member to hold off pending dry compression test results. I was waiting to see if he thought I should go ahead & do the wet test.