Misfire after 3k rpm...
09-04-2013, 03:08 PM
#1
Misfire after 3k rpm...
I have a 400 sbc thats giving me some misfire after about 3000-3500k rpm... It will cruise at 3k just fine pretty much but when I give some throttle it just starts missing. Motor has about 50 hrs on it and it has a 750 eddy on it. Plugs are gaped at .35 using NGK V power FR4 and running around 9.3 compression. Cap, rotor and wires where new 2 years ago.
Where should I start?
Where should I start?
09-04-2013, 04:51 PM
#2
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Just throwing it out there, not sure how bad it is. My engine had a slight constant miss at around 3500-4000 rpm. It did it holding an rpm though. I checked every dam electrical thing, put new plug, wires ect. Here it was the carb. Rebuilt carb and was fine. The constant miss I thought for sure it was electrical.
09-04-2013, 07:24 PM
#3
Just throwing it out there, not sure how bad it is. My engine had a slight constant miss at around 3500-4000 rpm. It did it holding an rpm though. I checked every dam electrical thing, put new plug, wires ect. Here it was the carb. Rebuilt carb and was fine. The constant miss I thought for sure it was electrical.
09-05-2013, 08:20 AM
#4
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That tells me you may need new plug wires. Running next to the block or bell housing shouldn't cause a miss fire if the plugs and wires are good., but they really shouldn't be laying on top of any metal either.
At least you found the problem, good job! Intermittent problems like that are a pain to find sometimes.
At least you found the problem, good job! Intermittent problems like that are a pain to find sometimes.
