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Plugs? Posted by Ari [Email]  (#2847) [Profile/Gallery]
(more from Ari) on Mon, 4 Apr 2005 05:58:28
In Reply to: Mild stumble under full boost - 97 aero 5spd, Luke S., Sun, 3 Apr 2005 15:04:12 Members do not see ads below this line. - Help Keep This Site Online - Signup |
Whenever I hear someone say stumble under full boost, I think spark plugs. Make sure they are the exact right NGKs, gapped per spec. Even a slightly wider gap can cause a problem, because the higher the boost, the harder it is for a spark to jump. The next thought would be to make sure that the little springs in the DI between the coils and plugs are properly seated. Basically, anything that increases the gap can cause a mis-fire. If all of that checks out, I'd inspect the DI coils. You can remove the DI and flip it over, and remove the plastic cover ( a few torx screws). Hold the coils up to a strong light - they should each be about 90% full of oil. There should be no signs of oil leakage, and no signs of burning on the coil bottom, where the spring connecting it to the plug sits. Leaky coils mean replacing the DI. Weak spring - clean it up and make sure it's seated properly.
It may be something else - you may be knocking slightly and you feel the turbo cutting back - but I doubt it. Start with the plugs. If you know they're fine because you replaced them recently, go back in and re-check the gap, and the springs.
posted by 192.249....
, Mon, 4 Apr 2005 05:58:28 <-- Viewing This Message
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