Spark knock help?

[86JeepXJ]

In the last 2 weeks, I have been having some major spark knock issues. I knew I had the timing advanced a bit, so I set it back to the emissions label recommended 12 degrees. Same problem. I had it at 16 degrees before. What the heck can be causing this? The engine is not running hot. I run 87 octane gas, and always have. Here are my specs, hopefully I can get some help on this one.

Could the recent lift on gasoline quality requirements be a cause for this?

1986 Jeep Cherokee 2.8
2SE carb
Hot air tube is not on
EGR is non functional
Timing set at 12 degrees BTDC
180* thermostat

Please help... I am going nuts!!

[geoffinbc]

EGR. Or its running lean. Sounds like tuneup time on the old carb.

[86JeepXJ]

Thanks, the carb HAS been acting up lately..... EGR has never been connected.

[854x4s15]

You can rebuild the carb pretty cheap. Did the carb on my 85 S-truck for about $75 plus another $90for the base gasket. If you do't want the heated gasket you can replace it with a generic one for around $20. Oh yeah ,if you get them truogh NAPA get the Blue Streak rebuild kit. The cheaper one has one gasket that is specific to the e2se carb and will not work on your 2se carb. You should change the EGR valve while your at it because you'll have to remove it when you pull your carb off anyway.

[86JeepXJ]

Oddly enough, I found a 2SE on an '83 Blazer back in the woods. Cured the problem, and it runs like a bat out of Hell now..... I found out also that my secondary was not opening but 1/4 of the way....And I did not have to take the EGR off to do the swap.

Thanks, folks!