High rpm misfire
09-05-2012, 12:47 AM
#1
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High rpm misfire The car is an ls2 gto with ls3 top end. At wot or near wot the car will start to misfire around 5k rpm or so. It does it about %50 of the time and does not throw a cel. I have replaced plugs and plug wires with no change. I'm not sure where to look next so any suggestions are appreciated.
09-05-2012, 06:04 AM
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Duty cycle is in the 70's so unless its a partially clogged injector its getting plenty of fuel. Valve springs only have a little over 20k on them but I'll have to pull the valve covers and take a look
09-05-2012, 11:32 AM
#5
Again, what plugs and gap? Springs sound very plausible though, it'll break up and miss like no other with crap springs.
09-05-2012, 07:56 PM
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Plugs are br6ef's gapped at .035. Springs are prc .650's with about 22k on them. Would a worn spring cause an erratic mis or would mis every time at high rpm?
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09-05-2012, 08:21 PM
#8
It really depends. Typically it'll break up and pull some then break up, and fall flat on it's face. Other weaker springs will probably miss all the time. It's a good idea to check springs every 20K or so. Since dropping valves is a bad thing.
