Misfiring m42... trouble shoot?

[smashed s4]

Hey guys,

My m42 has finally started after the replacement. Now it is misfiring... just swapped the plugs for brand new ones. I did the intake mess as well. I also put it brand new temp sensors. Checked the timing ticks, they are all straight up.

Here is a video of the horrible noises!

http://www.youtube.com/watch?v=aczKhBD6llk

http://www.youtube.com/watch?v=C1tJBql4mjA

http://www.youtube.com/watch?v=cEx_KMDa8AU

These videos are a bit redundant but you can get a feel of what is happening...
Thanks guys!!

[Dj Buttchug]

take a piece of printer paper and hold it a few inches away from the tail pipe and film it or film more at the tail pipe in general. It helps hear what the engine is doing without all the valve train noise.

It almost sounds like/ looks like its back firing? that knocking noise that happens every few seconds. In that case I would assume timing is off by a tooth or so...

Aside from all that whats the story? did you swap m42s? why?

[roguetoaster]

The first video sounded like coils/wires being out of order. Did you have the coils/coil connectors off for the swap?

Then I watched the second vid and it seemed like poor timing or maybe a badly seated intake or even a plug that is not sealing well.

[smashed s4]

So I swapped a donor m42 into this shell because the other m42 was seized. I'll try and get a video of the tailpipe today. Stay tuned thanks guys

Also, I checked the coil wires and plugs multiple times. They are correct.

[smashed s4]

It runs better at higher RPMs

[VANOS714]

i'd try changing the spark plug wires first.

[///M42 sport]

coil packs

[fourmotioneer]

Is there a resistance test for either the plugs wires or the coil packs?

[roguetoaster]

For the M42, .4-.8 ohm between outermost pins on ignition coils. 4500-5500 ohms for the spark plug wires. Also putting the word resistance in here so someone can find this down the road as it's slightly hard to track down.

[broach328]

run a comp test yet? have you verified that the crank is also at TDC with the cams? all that fun timing stuff thats so easy to access on the m42... :roll: