If he doesn't have either the SES light or a MAF code, then it isn't the MAF - in his car even an iffy MAF will throw one of a bunch of codes which point to air leaks and bad sensors - but he might want to check the electrical connector and also check the IAT near the air filter box.It could be mass air flow sensor
What makes you say that? If the wires are original, they're 11 years old.Plugs for sure, highly doubt its the wiring. I would start at the plugs though and go from there, do you feel any "bucking" or "hesitation" while your accelerating? and if so, does it happen at a particular speed?
There have been many, many pre-2000 Northstars come through here with the OP's exact symptoms. In almost every case an inspection of the plug wires revealed either tracked plug boots or outer shield cracking with resulting arcing to ground. At 100 kmiles+ the plug wires have outlived their design life. Time for a complete plug/wire change.Plugs for sure, highly doubt its the wiring. I would start at the plugs though and go from there, do you feel any "bucking" or "hesitation" while your accelerating? and if so, does it happen at a particular speed?
Somewhere back a few years ago there is a rather long detailed post by me entitled "Stutter, Engine or Trans?" if you care to search it out and read it. Short version is after the fuel rail recall was done to my '97 Deville I developed what turned out to be a misfire (I wasn't 100% sure, hence the title). Long story short, after replacing the plugs to no avail, I replaced the wires (at 75K) and that cured the problem. Like you, I did not expect them to be the problem. I now have a different view of ignition wires.Because mine are 17 years old and nothing wrong at 215k miles, I am just trying to pin point where it is obvious to start, because typically when you do a "routine" tune-up, its uncommon to need wire and boot replacements for the plugs.
As far as the plug wires are concerned, the "easiest" inspection is a visual inspection with the beauty cover removed on a dark night. You might see a corona glow, but you would not want to see any arcing. It would help to have a "trusted" friend torque brake the engine in gear to simulate normal engine loads and greater demand on the plug wire insulation.....but this post is really making me start to look around later this weekend and inspect my wires to see any noticable cracking at the boots and see if any replacement is needed.
Well then! This makes me want to change them out for fun, just so i never have to deal with that. Thank youA word to the wise. Leave well enough alone if you are not having any problems. As I said, my misfire started after the fuel rail recall was done. In order to do that they had to pull the left bank plug wires and move them out of the way. Apparently moving the old wires around caused the problem. Visually, they where perfect. No external breaks or cracks at all, but it caused an internal problem that caused a misfire under a light load. It ran perfectly at WOT.
Well i know this as far as being an electrician myself. As i say with anything else i touch under any hood i own, "Dont touch it unless you feel comfortable replacing it." :tisk:Plug wires slowly become less and less flexible over the course of several thousand thermal cycles and moving them around for "inspection" is counterproductive. Avoid moving the wires if possible !!