Misfire??
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Joined: May 2006
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Misfire??
Hey guys,
Another problem in the ongoing saga:
Took Bruno (86 f150 5.0 EFI) out for a smog check and his HC's were a tad too high at 108 ppm. A bit above legal limit and well above average. I know HC's being high is a sign of a misfire and I think I can feel it when he's warmed up (some stumbling). It only happens when he's warmed up and running but never at idle. In fact, he idles so beautifully it's hard to believe that a 20 year-old car could sound so good (except for one thing; there is a slight ticking noise, which I suspect to be a valve in motion. Don't know if it's damaged or has anything to do with suspected misfire). I've checked the timing of each cylinder at idle with spout disconnected and they all fire like clocks; perfect.
Anyway, I'd love some advice on the high HC's and how best to locate a misfire. Thanks in advance.
Another problem in the ongoing saga:
Took Bruno (86 f150 5.0 EFI) out for a smog check and his HC's were a tad too high at 108 ppm. A bit above legal limit and well above average. I know HC's being high is a sign of a misfire and I think I can feel it when he's warmed up (some stumbling). It only happens when he's warmed up and running but never at idle. In fact, he idles so beautifully it's hard to believe that a 20 year-old car could sound so good (except for one thing; there is a slight ticking noise, which I suspect to be a valve in motion. Don't know if it's damaged or has anything to do with suspected misfire). I've checked the timing of each cylinder at idle with spout disconnected and they all fire like clocks; perfect.
Anyway, I'd love some advice on the high HC's and how best to locate a misfire. Thanks in advance.
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New User
Joined: May 2006
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Misfire
Checked for arcing at night and no dice, no sparks flying or anything. I'm open to more suggestions. The misfire only happens under load when driving. At idle, in park, even with the throttle open, it has no problems. But at about 20-25 mph, it starts to shudder and stumble a bit. Any other ideas? Appreciate the help, thanks.
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Joined: Oct 2004
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my sugestion would be check the plugs and see if they are still good i had a ranger that did that after the motor was changed it was caused by the pcv valve being busted and sucking oil into the intake. i changed the plugs and valve and never had a problem after that.
tony
tony
