Cylinders not firing...

[Dubv1980]

Ok, 1976, ex-MOD 109. My friend and I replaced the head gasket today as we had noticed white smoke from the tailpiple..and it was going through coolant. Well, we've got the motor put back together now..no more white smoke, coolant is staying up, but now we've got the #3 and #4 cylinders not firing. The plugs are getting spark, but if I remove the plug wire..there's no difference in the rough idle. I can take the plug out and hold it up against the engine block, and the plugs are firing (maybe not hot enough...the were more an orange spark than blue?)
We took the valve cover back off..the valves all seem to be operating. Any other ideas? Anything to look for?

Chris

[4flattires]

Start with the basics....

1. Ensure the firing order is correct.
2. Compression check (post results)
3. Swap plugs to see if the fault follows the plug (plugs can look good, but perform poorly.
4. Use your timing light to ensure plug wire is firing with consistency.

Unless you left a shop rag in the intake manifold, your pretty much assured its not a fuel problem.

Jeff

[Dubv1980]

Update

Ok, well I don't have a compression guage yet, but I did replace all the plugs, with no change.
The plugs are plugged in to the right spots on the cap. Adjusted the timing..all is well..but still two cylinders that are not firing. The compression test will tell more I suppose.

Chris

[Mercedesrover]

Maybe you've got a couple valves adjusted too tight?