GeneralDisorder Posted March 12, 2023 Share Posted March 12, 2023 Have you carefully inspected the plugs and wires? This sounds exactly like what I've seen when spark plug wells get water in them, or plug wire end connectors get corroded, etc. Ohm the wires - looks for cracks on spark plugs and look for burn marks on the plug wire insulators. I've seen them arc out through the insulation to the plug well. It usually manifests just the way you describe because cylinder pressure is rising and coil dwell time is long leading to a lot of secondary ignition voltage and higher resistance at the plug gap.... I would install new wires and plugs and gap the plugs to 0.025" and see if that doesn't resolve it or significantly improve it. GD Quote Link to comment Share on other sites More sharing options...
carfreak85 Posted April 10, 2023 Author Share Posted April 10, 2023 OK, ohm'd the plug wires, and the Densos (that were a few years old, but by no means ancient) were coming out at 7-9 kohms, while the new NGKs I installed were in the 3.5 kohm range. The throttle related hesitation has all but disappeared during normal driving. Spark plugs have not been change yet (NGK iridium 11s), but the spark plugs were dry of oil or water. There is still a slight sag in power after the 1-2 shift on cold mornings, which was the original symptom, so I guess we're back to square one. Quote Link to comment Share on other sites More sharing options...
Steptoe's photos Posted April 10, 2023 Share Posted April 10, 2023 I hope my 1999 Forester issue does not go on for this length of time ! Quote Link to comment Share on other sites More sharing options...
heartless Posted April 10, 2023 Share Posted April 10, 2023 49 minutes ago, carfreak85 said: OK, ohm'd the plug wires, and the Densos (that were a few years old, but by no means ancient) were coming out at 7-9 kohms, while the new NGKs I installed were in the 3.5 kohm range. The throttle related hesitation has all but disappeared during normal driving. Spark plugs have not been change yet (NGK iridium 11s), but the spark plugs were dry of oil or water. There is still a slight sag in power after the 1-2 shift on cold mornings, which was the original symptom, so I guess we're back to square one. it has been said many times over... NGK copper core plugs - you do NOT need the fancy iridium, platinum, or anything else.. just plain old copper cores set to the correct gap NGK or OEM wires ONLY - anything else is a waste of time and money. Sure, they might work for a little while, but they WILL fail prematurely Quote Link to comment Share on other sites More sharing options...
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