Driver side backfiring

[jforest1]

I've done my alternator upgrade and put the exhaust manifold back on to make sure everything is good electrically.

So running open exhaust manifold, I'm backfiring driver side at ~2000rpm. I triple checked the spark plug cables are correct.

I'll probably switch out the spark plug sides tomorrow morning after the engine cools and see if the backfiring moves to the passenger side.

If it were running rich it would be backfiring out of both sides, correct?

Any other reasons why backfiring out of one side only might be happening?

JF

[MEK-Dangerfield]

There could be a leak. Try to tighten the bolts on the exhaust manifold again. 

[jforest1]

What kind of leak?

I tightened to 120 inch pounds from the manual, but I made an educated guess at which bolts they were referring to.  Is that correct?

JF

[Chryco Psycho]

is the engine runnig smooth ?
if si with the manifold open the extra fuel in the manifold my be burning as it hits the oxygen at the manifold opening . Other possibilities are it is rich or lean at that RPM

[jforest1]

is the engine runnig smooth ?
if si with the manifold open the extra fuel in the manifold my be burning as it hits the oxygen at the manifold opening . Other possibilities are it is rich or lean at that RPM

Yes so switched out the plugs and now both sides are backfiring.  I'm thinking I didn't have a good vantage point last time on the driver side and now am doing it but probably was both sides before.  So I'm thinking now it's just running a bit rich as ambient temperature is much hotter.

JF

[jforest1]

Just to close this up, I've put the pipes back on and it is no longer backfiring.

JF

[mojavered]

Sounds like it was a back pressure problem?