datzenmike Posted March 30, 2023 Report Share Posted March 30, 2023 Swap the two wires and see if it moves to another cylinder. If verifiable that it's not spark try adjusting the the idle mixture a bit richer. Spray WD-40 around the #4 intake at the head. Check the bolts are tight. Quote Link to comment
yzBailey Posted March 30, 2023 Author Report Share Posted March 30, 2023 I think I have something internal going on because my brand new plug is already totally black with what seems like oil and I can see liquid in the number 4 cylinder with my bore scope Quote Link to comment
datzenmike Posted March 30, 2023 Report Share Posted March 30, 2023 That shouldn't be in there and isn't caused by a miss fire. The miss fire is caused by IT Quote Link to comment
yzBailey Posted March 30, 2023 Author Report Share Posted March 30, 2023 I have good compression though so I’m not sure what could be wrong internally Quote Link to comment
Yinzer Posted April 14, 2023 Report Share Posted April 14, 2023 On 3/27/2023 at 3:25 PM, datzenmike said: I would quickly confirm that the valve clearances are ok. As it was recently adjusted/disturbed it's possible that a lock nut came loose. Easy cheap fix if it is. Intake BP6ES NGK Exhaust BP5ES NGK absolutely MUST be NGK plugs, and not those counterfeit ones on Amazon Describe miss fire. Random all the time? Only at speed? Only under load? Only at idle. If only at idle, turn the idle speed screw down and turn the idle mix screw in and out stopping when the idle quality drops off in either direction. There's probably half a turn or more where it runs fairly well, just set roughly in the middle. If idle went up from the improvement then turn it back down and repeat as many times as needed till you can't improve the idle quality and the idle is about 700. This only adjusts the idle mixture say 550-1,100 and not the entire range. If random all the time, pull and inspect the plugs for a cylinder that may be struggling. It may be carboned up from miss firing, or oil fouled. Look for plugs that are different from all the others. Try idling while it misses and one at a time pull each spark plug wire off. You might have to turn the idle speed up slightly to keep it running. It should run rough but evenly on a single plug but the miss should be even more apparent. When you unplug the 'bad' wire/plug it should idle better than the other 7 . Which direction do you turn the mixture screw to make in more LEAN ? Is it controlling air flow or fuel flow ? Quote Link to comment
datzenmike Posted April 14, 2023 Report Share Posted April 14, 2023 Turn idle mixture screw adjusts fuel flow... in to lean and out to make richer. Idle mixture screw... it only adjusts the idle mixture. Has no effect on regular running when driving. Idle speed screw adjusts air flow. 1 Quote Link to comment
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