4.9L hesitation
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Joined: May 2002
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4.9L hesitation
Well, I finally got time to check out the EGR valve and I unpluuged the vacuum line and plugged it. All the problems stopped (hesitation and engine surging). I will now replace it since I'm in NJ and inspections are tough. The idle even smoothed out a bit. Thanks for the help guys.
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Joined: Dec 2001
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From: Southeast FLA
4.9L hesitation
gsc1996, You might think about plugging it, or restricting it, internally, but leave the vacuum hose hooked up to make it look right - then see if it passes inspection.
There's no need to unhook the vacuum line after a restrictor plate in in place - and for the restriction or blocking of flow, some Ford garages reportedly use ***** of tin foil stuffed down the EGR tube (if you're looking for a less noticeable block).
There's no need to unhook the vacuum line after a restrictor plate in in place - and for the restriction or blocking of flow, some Ford garages reportedly use ***** of tin foil stuffed down the EGR tube (if you're looking for a less noticeable block).
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Joined: Jul 2000
Posts: 429
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From: Lima, OH
4.9L hesitation
Something that hasn't been mentioned that I got from the oiginal posting for the EGR restrictor plate is that you can "tune" it by drilling a small hole to allow some EGR effect to take place, then keep slightly keep increasing the hole until you get the best results.
This still allows the EGR to function, but reduces its effect that causes the lean condition. As the engine wears over time less EGR is needed, but the computer has no way of measuring this. By reducing the hole size via the restrictor plate, you are (in theory) able to restore proper EGR flow to match your engine's condition. If I recall right, the EGR port is around 3/4" or so, so I'd start with a hole around 1/4 - 3/8" and go from there in 1/8" increments.
Just don't ask how you'll know when you have the right sized hole, because there isn't really any specific way to calculate / measure / cross check it that I know of.
This still allows the EGR to function, but reduces its effect that causes the lean condition. As the engine wears over time less EGR is needed, but the computer has no way of measuring this. By reducing the hole size via the restrictor plate, you are (in theory) able to restore proper EGR flow to match your engine's condition. If I recall right, the EGR port is around 3/4" or so, so I'd start with a hole around 1/4 - 3/8" and go from there in 1/8" increments.
Just don't ask how you'll know when you have the right sized hole, because there isn't really any specific way to calculate / measure / cross check it that I know of.
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