Hey All, I've read about a few similar problems, but most sound like not 100% same symptoms. I recently bought a 2006 Mustang GT, manual, 95k miles. Seems to be very stock mechanically and mostly original parts besides being straight piped and had K&N drop in air filter.
It runs good when cold and for first 5 minutes driving. Then it starts to seem to "miss" and can have a few bucks when accelerating lightly-moderately. Does not seem to have an issue with hard acceleration. Most noticable problem is when it's been running awhile, and just cruising at a steady speed, it will continually buck lightly... like your being pushed very lightly about 1.5 times per second. When I come to a stop and it's idleing, the rpm are steady, seems fine at idle even when hot. Happens in all gears/speed... don't remember it being as noticeable at very high speed.
I'm not very experianced at diagnosing, can do minor repairs/testing. Was thinking it may be a weak spark in a cylinder. Had Ford dealer put in new spark plugs, also asked them to put in new fuel filter. I changed the engine air filter(oem).
Ford didn't replace the coil packs, so I bought one coil pack and tested it using multi-meter, between pins and between pin and coil. Tested each of my original coil packs and they are all close to the same.. so probably not bad coil pack.
Going to do an oil change this weekend. I have a cheap scan tool, shows no codes when starting the car... maybe I need to have it plugged in while driving - will try this. If oil change doesn't solve it, what should I check for my symptoms?
I've read about trying some chevron fuel additive, will look for this.
Thanks!
Deonild
It runs good when cold and for first 5 minutes driving. Then it starts to seem to "miss" and can have a few bucks when accelerating lightly-moderately. Does not seem to have an issue with hard acceleration. Most noticable problem is when it's been running awhile, and just cruising at a steady speed, it will continually buck lightly... like your being pushed very lightly about 1.5 times per second. When I come to a stop and it's idleing, the rpm are steady, seems fine at idle even when hot. Happens in all gears/speed... don't remember it being as noticeable at very high speed.
I'm not very experianced at diagnosing, can do minor repairs/testing. Was thinking it may be a weak spark in a cylinder. Had Ford dealer put in new spark plugs, also asked them to put in new fuel filter. I changed the engine air filter(oem).
Ford didn't replace the coil packs, so I bought one coil pack and tested it using multi-meter, between pins and between pin and coil. Tested each of my original coil packs and they are all close to the same.. so probably not bad coil pack.
Going to do an oil change this weekend. I have a cheap scan tool, shows no codes when starting the car... maybe I need to have it plugged in while driving - will try this. If oil change doesn't solve it, what should I check for my symptoms?
I've read about trying some chevron fuel additive, will look for this.
Thanks!
Deonild
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