Cylinder 8 Misfire Diagnosis

[Lethalweapon100]

might be t chain

Goodie goodie. I was hoping I'd have to do that. /s

Heres my readings from the coil. What do you think about this? Im not very expirenced with a multimeter, but this reading from the coil doesnt seem right. With my multimeter set to 20K Ohms, i measured the resistance of the coil from both posts in the plug to the output post on the coil. It came up with 13.65 on one post and 13.66 ohms on the other, and my sm says it should be:

http://imgur.com/ORf5rM8

Not sure what this means for me. Can someone interpret this?

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[Merc225hp]

Goodie goodie. I was hoping I'd have to do that. /s

Heres my readings from the coil. What do you think about this? Im not very expirenced with a multimeter, but this reading from the coil doesnt seem right. With my multimeter set to 20K Ohms, i measured the resistance of the coil from both posts in the plug to the output post on the coil. It came up with 13.65 on one post and 13.66 ohms on the other, and my sm says it should be:

Imgur: The most awesome images on the Internet

Not sure what this means for me. Can someone interpret this?

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So 1.36 outta spec but not buy much.

 

[Lethalweapon100]

So 1.36 outta spec but not buy much.

So the coil isn't the problem, you think?

Should i check cam and crank sensors next? What else? I dont want to dive right in to a timing chain if im just guessing.

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[Merc225hp]

CKPS can be a pita to check with a dvm but go for it. Test anything you can. I still say a comp test is needed.

 

[Lethalweapon100]

CKPS can be a pita to check with a dvm but go for it. Test anything you can. I still say a comp test is needed.

Ill do that tomorrow.

Why do you think it would start doing this so randomly?

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[Merc225hp]

Don't buy any parts till after the comp test has been done, don't need to see you wasting cash on parts u don't need. Hard to say other than something has gone outta spec.Can you test the fuel psi by chance as well.

 

[Lethalweapon100]

Don't buy any parts till after the comp test has been done, don't need to see you wasting cash on parts u don't need. Hard to say other than something has gone outta spec.Can you test the fuel psi by chance as well.

I won't, i might need to buy a new comp tester though. Gauge on mine is f'd.

How do i test fuel pressure? Should local parts stores have a rental tester?

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[Merc225hp]

I won't, i might need to buy a new comp tester though. Gauge on mine is f'd.

How do i test fuel pressure? Should local parts stores have a rental tester?

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That sucks but getting a new tool is always a good thing.

There should be a test port on the fuel rail divers side and you should be able to rent the tool.

 

[Lethalweapon100]

That sucks but getting a new tool is always a good thing.

There should be a test port on the fuel rail divers side and you should be able to rent the tool.

Alright. Welp, its dark and raining now here, so we'll find out tomorrow. Thanks Merc, always a great help.

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[Merc225hp]

Np man hope it all goes well for you tomorrow.

 

[Lethalweapon100]

Np man hope it all goes well for you tomorrow.

Hey I didn't do the tests yet, xmas has kind of taken a priority. But something i noticed today, its a lot warmer than usual here (usually its 30-40, today its 70 degrees F) and the truck is running hot at idle and stoplights. On the highway, the temp gauge stays a hair above 200, and at stoplights and idle, it probably runs about 225-230. Pretty hot for this truck, about halfway between 200 and the overheating zone. Im experiencing no coolant loss at all. This is a new thing for me that just started today. ???

The truck did misfire a few times on the highway, the CEL turned on for .5 seconds then turned right back off. It had no active or stored codes after. WTF?

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[bassslayer25]

Hey I didn't do the tests yet, xmas has kind of taken a priority. But something i noticed today, its a lot warmer than usual here (usually its 30-40, today its 70 degrees F) and the truck is running hot at idle and stoplights. On the highway, the temp gauge stays a hair above 200, and at stoplights and idle, it probably runs about 225-230. Pretty hot for this truck, about halfway between 200 and the overheating zone. Im experiencing no coolant loss at all. This is a new thing for me that just started today. ???

The truck did misfire a few times on the highway, the CEL turned on for .5 seconds then turned right back off. It had no active or stored codes after. WTF?

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Have you done your plugs, wires etc?

 

[Lethalweapon100]

Have you done your plugs, wires etc?

Approx 20k ago.

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[bassslayer25]

Approx 20k ago.

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Have you checked them lately?

 

[Lethalweapon100]

Have you checked them lately?

Cyl 4 looked good, 8 looked absoultely terrible. Im about to comp test all 8 cylinders so ill let you know.

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[Lethalweapon100]

Heres the results of my compression test. I didnt have time to do cylinders 5 and 7.

http://imgur.com/cDZd7Uo

The fourm doesnt like to host images for me for some reason, so theres that.

As for all the plugs, they looked pretty good, maybe slightly lean. Other than that they looked like they had a pretty normal burn. 8 was a bit oily. All the ones that say "dirty" just had dirt on them from pulling them out of the hole.

I didnt have time to buy the fuel pressure gauge, either. Til after xmas.

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[Lethalweapon100]

Np man hope it all goes well for you tomorrow.

Check out my last reply, Merc. Did my comp test.

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[dapepper9]

Check out my last reply, Merc. Did my comp test.

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Numbers look good!

 

[Lethalweapon100]

Numbers look good!

Think so? Cyl 8 seemed kinda low compared to the others. Not bad for a 220k mile motor with no history that i know of.

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[dapepper9]

Think so? Cyl 8 seemed kinda low compared to the others. Not bad for a 220k mile motor with no history that i know of.

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Compared to the others, a little but it's still in spec