Developed a misfire...it seems

[dude8383]

**Problem Solved, See post # 5**

Hey guys,

Tried searching around but didn't find anything too conclusive.

For reference:

M50B25 block, m52 crank, rods and pistons...2.8liter m50.

I was driving a couple of hours ago and all of a sudden the car started to hesitate across the entire powerband, I kinda peddled it home. When I finally came to a stop the car sounded like it wasn't firing on all cylinders. There is some vibration as I accelerate, no symptoms on deceleration though (no fuel or spark right?)

I was thinking to start pulling the coil harness to see if anything changes to narrow down which coil is the culprit. OR it may be a spark plug?

Is this a proper method for checking a misfire?

[99em1]

first I'd pull the coils and see if there's water/oil/whatever in there. then pull the plugs and take a look at those too.

and what motor? i'm guessing you didn't throw a cel

[325issguy]

Sounds alot like when I had a bad vaccume leak...

[dude8383]

first I'd pull the coils and see if there's water/oil/whatever in there. then pull the plugs and take a look at those too.

and what motor? i'm guessing you didn't throw a cel

i actually have a spare set of coils that i will try but first im going inspect before replacing anything.

motor info added in original post, yeh no CEL.

Sounds alot like when I had a bad vaccume leak...

this is a pretty clear misfire, i doubt a vacuum leak could create something like this. i'll post up a video in a few.

[dude8383]

Problem solved.

MrSlacker came by and gave me a hand. I started with coil/spark plug 1, spark plug was a little oily but the coil itself looked fine. I replaced it with a spare anyway. Slacker started it up and the problem coil immediately made itself known...I saw the spark against the valve cover.

Pulled coil # 5 and found this:





I guess its time to replace all 6 huh?

[ck_taft325is]

I wonder if that's what's wrong with my S50... mmmm.

[99em1]

cool. i always wonder if new coils would make a difference in mine. can't justify new ones though till i know they're toast. if it aint broke... and all

[ZM Blue Devil]

Denis, I have a couple of NOS coils, let me know.

[samiam3356]

Thanks for sharing how you fixed it. Hate when I see these threads with no resolve.

[dude8383]

cool. i always wonder if new coils would make a difference in mine. can't justify new ones though till i know they're toast. if it aint broke... and all

well i purchased my coils used but i will purchasing new ones after this. generally if one goes bad then the others will follow suit sometime after.

Thanks for sharing how you fixed it. Hate when I see these threads with no resolve.

no problem man, i hate seeing threads that don't have a solution either!

:up:

[audiphile]

well i purchased my coils used but i will purchasing new ones after this. generally if one goes bad then the others will follow suit sometime after.

I logged in just to say that sometime after can be anytime from today to never, just like when you get them new. save your money and buy just 2 spares :)