What did I do wrong with plugs?

[beartard]

[SOLVED] What did I do wrong with plugs?

I'm gonna be the first to admit 'tardation on this one. I've never had any trouble changing plugs on any previous vehicles. This is the first time I tried on the Liberty and even read the HOWTO here first so there wouldn't be any surprises.

It went well. Did it one side at a time. Autolite platinums, gapped right. Seemed like an easy fix. Only thing I didn't do is test-drive it afterwards.

I went to get some supper and now I'm throwing a check-engine light and it runs like hell. Definitely not hitting on all eight..er..six, so to speak. Also, the check-engine light stays on even in ACC. While running, it will blink sometimes and stay solid at other times.

So I pulled out the back two plugs on the passenger's side again, thinking if I had done anything wrong, it'd be those two since they're the hardest to get to. Everything seemed fine, but the Liberty still isn't running right.

It was too dark to play around any more tonight, but can anyone think of what I might have missed or done wrong so I'll have a better chance at fixing it in the morning? I'd appreciate it.

 

[ShadowedXistence]

First of all what codes are you getting? If you don't know how to find out, read the thread on how to do so. Second, did you put the washer like rings on the spark plugs before installing? I know some plugs already have them on and others you have to put on yourself. Also, if you remove the two nuts for the coolant tank, you can move it out of the way a little to better get at cylinders 4 and 5. Double check your wires for the ignition coils and be sure the ignition coils are seated properly.

Most of all, the codes are what's going to help determine the issue!

 

[tjkj2002]

If you checked the gap on those plugs with a metal gapper you just ruined those plugs,use only a plastic or composite gapper for platinum plugs.Check the coil connectors and make sure they are fully clipped in.

 

[kb0nly]

Hmm... I use a metal feeler gauge to check plug gap and i haven't ever scratched or ruined a Platinum plug.

 

[tjkj2002]

Hmm... I use a metal feeler gauge to check plug gap and i haven't ever scratched or ruined a Platinum plug.

You have and just have not noticed,the electrode is just platinum coated with a copper core,so by using a metal gapper is just scratches the platinum off exposing the copper core,the plugs work the same but will no longer last as long.

 

[beartard]

The code I get (wasn't aware you could check yourself) is P 0304, which means "cylinder 4 misfire."

 

[RageOfFury]

The code I get (wasn't aware you could check yourself) is P 0304, which means "cylinder 4 misfire."

Then pull the #4 plug and have a look at it and check the coil. Could possibly be a bad plug. Happens from time to time that one slips though QA.

 

[beartard]

Then pull the #4 plug and have a look at it and check the coil. Could possibly be a bad plug. Happens from time to time that one slips though QA.

That makes sense. What is the pattern for numbering that Jeep used?

 

[ShadowedXistence]

6. 5
4. 3
2. 1

Lokking at it from the front

 

[beartard]

Thanks. I'll check it first thing in the morning. Well, maybe first thing after it warms up.

 

[04Liberty]

Did you completely disconnect the coil? If it didn't get plugged back in right, then it'll through that code.

 

[beartard]

Yeah. I completely disconnected all the coils. Everything else was done according to hoyle as well.

 

[riptricket]

tjkj i asked two separate automotive places today, and they said that unless you are really really rough with the plug, then you can't scratch off the platinum coating.... granted I side with you more, but since they don't have any non-metal gappers here, I am SOL.

 

[belvedere]

If you go here: http://www.autolite.com/products/platinum.php, and click on Instructions, and then Step 4, it gives gapping instructions for the Autolite platinums. Nothing about a special feeler gauge, and the drawing sure looks like a traditional wire-type gauge. If the coating were so thin as to be removed by touching it with a metal gauge (really, all you should be doing is touching it), it would be gone in a few thousand miles of engine operation.

 

[ridenby]

To OP,swap coils around,ie,4 to 1 and vice versa see if if miss travels with coil.

 

[kb0nly]

If you go here: http://www.autolite.com/products/platinum.php, and click on Instructions, and then Step 4, it gives gapping instructions for the Autolite platinums. Nothing about a special feeler gauge, and the drawing sure looks like a traditional wire-type gauge. If the coating were so thin as to be removed by touching it with a metal gauge (really, all you should be doing is touching it), it would be gone in a few thousand miles of engine operation.

Yeah that's my thought too. If the coating was that thin and fragile it would burn off in no time.

I have a platinum plug in my lawn mower even, and i just pulled that to get the lawn mower ready for winter. Two years that's been in there now, and i gapped it with my metal feeler gauge. There is no sign of wear or electrode loss. Now granted a vehicles engine sees more constant use, but i'm just saying i know by looking at that one i didn't hurt it any.

I have a spare platinum plug for my chainsaw... I will take that and see how much pressure it actually takes to scratch off the platinum coating and see the copper underneath.

 

[incommando]

My first those was coil, too. From a loose connection to bumped and damaged. Much more likely than a bad plug.

 

[beartard]

I swapped two coil packs (between 2 and 4) and still got the cylinder 4 misfire and rough idling.

Then I swapped plugs between cylinder 1 and 4 (since 1 is easiest to get to.) Now I get codes for cylinder 1 and 4 misfiring. Do the codes clear themselves when the problem goes away or do they have to be reset?

So here's what it seems to be:
If the codes don't reset themselves, I think it means that the plug I had in cylinder 4 is the culprit. I'm gonna go get some lunch and grab a new plug to see what happens.

If the codes do reset themselves, I have no clue what's going on.

 

[JeepJeepster]

No, a code typically will not reset itself till many starts and stops. Best thing to do would be to replace that spark plug now before it harms something. Youre probably pumping raw gas out of the exhaust which is not good for the cats. May not be enough to harm anything but I would fix it as soon as possible. Its like a $3 plug anyway.

When you switched the coils, did you switch them back after you switched the spark plugs? If you moved both the coil from #4 cylinder and the spark plug you didnt really figure anything out if it switched to cylinder 1.

Its not the recommended way to do things but you can unhook the battery for ~10min and clear the codes.

Make sure no grit that built up around the coils is falling down into the engine. When you take those plugs out.

 

[beartard]

No, a code typically will not reset itself till many starts and stops. Best thing to do would be to replace that spark plug now before it harms something. Youre probably pumping raw gas out of the exhaust which is not good for the cats. May not be enough to harm anything but I would fix it as soon as possible. Its like a $3 plug anyway.

I just replaced it and things are running well, though the check-engine light is still on. Last night I searched and read every spark plug post on this board before posting myself. I read somewhere that the PCM shuts down the fuel injectors for a cylinder if it's not firing. Is that true?

When you switched the coils, did you switch them back after you switched the spark plugs? If you moved both the coil from #4 cylinder and the spark plug you didnt really figure anything out if it switched to cylinder 1.

When I swapped the coils, I swapped cylinders 2 and 4 (4 was the problem). I didn't bother swapping them back once I found out that 4 was still misfiring. That eliminated coil packs as the culprit (unless it was a wiring problem). When I swapped the plugs between cylinders 1 and 4, I only moved the plugs, not the coil packs. That established the plug as the problem.

Its not the recommended way to do things but you can unhook the battery for ~10min and clear the codes.

Make sure no grit that built up around the coils is falling down into the engine. When you take those plugs out.

I was following your HOWTO