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Do you think it could be a vac leak? High mileage vac hoses get brittle and every can nowadays has one of those silly plastic covers over everything and it can be tough to see.
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Wife’s van getting misfire codes
- Thread starter great white
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Nope. been checked and all weathered hoses replaced.
Most vac leak issues tend to show up as "MASS AIR" obd codes on modern vehicles these days... the ECM sees a lean mix on the O2 sensors that doesn't jive with the fuel it's calling for. Basically, you're getting unmetered air downsteam of the MASS airflow sensor.
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It's not just the hoses, but also any fittings or junctions. The junctions are not always metal, and even the metal ones can leak. Small leaks don't always show as mass air errors.
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not the issue.
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You've sprayed every vacuum hose end and junction? If yes, you are thorough, if no, you're only guessing.
Standard troubleshooting practice, as you well know, is to prove or test the things you know. That way you know it for sure, rather than surmising it. If you work that way, my apologies, just trying to get you to state what you clearly know, vs what you may be imagining you know. This technique works for me as it helps me separate known validated facts from assumptions. Hope this helps, if not, I'll bow out now.
Standard troubleshooting practice, as you well know, is to prove or test the things you know. That way you know it for sure, rather than surmising it. If you work that way, my apologies, just trying to get you to state what you clearly know, vs what you may be imagining you know. This technique works for me as it helps me separate known validated facts from assumptions. Hope this helps, if not, I'll bow out now.
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I'll say it again: not the issue.
I was a licensed mechanic when I was 19. That was more than a couple decades ago (shy about my age, lol!).
When I say something that basic is not the issue, it's not the issue.
I'm not trying to be arrogant, it's just not the issue.
With all the sensors and logic controlling the ignition, a bad connection on almost any of them can cause seemingly random misfires. A bad connection on one of the inputs should flag an error but a bad connection on the output to ignition module may not.
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Guys, I've chased this down. It's the followers, possibly a lash adjuster (although not as common).
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Anybody here missing their old 283s?
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