misfire solutions :D

[vaspen]

ok heres what i have had happen to me feel free to post your missfire problems and how you fixed it


first my car had a small miss to start when i got it ..
gradualy the miss got bad enuf to the point the s/c shut off, then made it seriusly miss
so we cleaned the maf sensor worked wonders :)
untill i went into town ... the correct readings made the coilpack give out X.d
so after 115$ from nappa :D we fixed the majore :P missfire
now it was starting to get bad agen so i orderd a plug wire that goes under the coil pack (wondered why they sold them seprate ? get one and check the length)
replaced the wire from the bad coil pack now guess what..... absolutly no missfire now :) folows thru like a boss lol
there was a 1/4 in diffrence in length of the wire
anywho this is how i fixed my missfire still gotta put my bosh plugs in lol
feel free to say how you fixed your miss itl help others looking

[taz069]

When i rebuilt the head on my 96 c280 i also hade the valve cover blasted for that deep clean. I repainted with high temp clear coat. I didn't think of the coil packs' having to have a good ground. The bottom of the valve cover has a few spring shaped items that supposedly ground the cover to the block. I ended up running a ground wire from the block hitting each coil. In this some of my issues have been resolved. Just a thought for anyone that wants to spend a little time (1hr-2hr) and make sure their coils are positively grounded to the block and not rely on old spring's insinde the cover. Just a thought. It helped mine.

[vaspen]

thats what the one screw is for on the coils that has the metal side on it
but it should already be grounded by the bolts that hold the valve cover on to the block

[taz069]

The bolts that hold the valve cover down are isolated by the rubber bushing that is underneath the sleeving the bolt runs thru. And as for the bolts that hold the coils down they only bolt into the valve cover, and seeing the valve cover is isolated from the head via a rubber gasket It would only seem feasiable to ground the coils accordingly.

[vaspen]

the threads on the bolts that run down the head onto the engine block is what complets the ground the bolts that hold the coils down are bolted to the head witch in turn is bolted to the block

[taz069]

Vaspen now on my 96 c280, m104 my 3 coils bolt down to the top side of the valve cover. They are held in place i.e. by the way of the allen bolts that secure the plastic cover over them that run the length of my lil 6 cylinder. I had to helicoil some of the cover bolts due to a previous owner's over tightening. And none of them passed thru the cover to the block well atleast not on mine. Now I do understand how the head bolts work seeing I had to replace my head gasket. But the valve cover in my opinion is isolated and only touches the block by the way of the spring clips on the bottom side of the valve cover. Seeing their are rubber gaskets below each spark plug hole, the rubber gasket around the whole valve cover, and the rubber grommets that the valve cover bolts go thru and protrude around the washer that the valve cover bolts go thru. I just took it a step further to be absolute sure. I know for a fact it helped mine!! Sorry for the rant.

[vaspen]

I know the coils are positive and need to be kept away from the ground with the rubber to make the current to the spark plug direct but im saying on my little 4 banger 230k I have pulled the coil packs that sit atop the motor are fastend down by a single bolt apeace that is grounded incase something goes wrong (im not saying this will interfere with the spark sequence ) now with the valve cover and coil packs together without any gromits inplace the cover is attached to the head without rubber spacing hence the threading on bolts goes down into the hole witch is part of the block, think of the knee bones connected to the leg bones song without cartlige in the way , n sorry aswell about it I think we may be confued as to what the other one is saying