My car has always idled a bit rough when in drive and stopped...this morning, I replaced the spark plugs and ignition wires (Bosch Platinum+4's and factory wires), and the problem got WAY WORSE. It won't idle rough in park, but if I'm sitting at a stop light, it shakes so hard my teeth chatter. I've verified all the connections are solid, and I didn't knock anything loose/forget to reconnect anything...any ideas what's going on?
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89 Grand Marquis LS with 107K miles (as of 1/13/07). As proof of my undying love, I've invested:
- New exhaust
- Front brakes
- Rebuilt tranny
- New vinyl top
- Alternator & Battery
- And still going. -
Most people have had good and bad experiences with Bosch plugs, but I haven't and neither has any of the cars I have owned either.
I tried using those same exact plugs in my old 93 Eagle Talon and it had almost all of the same symptoms. It would misfire so bad that you could not accelerate when you would hit certain RPM ranges (1500, 2500-3000) and the entire car would rattle your teeth. The car could not idle either, it would just oscillate. I put champion spark plugs in it, never had a problem ever again. I was running just stock replacement wires also.
If you can, I would take those plugs back to the parts store and get some different ones. Autolites or Motorcraft plugs should only be used in older Fords from my experience and my dad's Fords.Current rides - 1991 Ford Thunderbird 3.8 v6 (gas saver/DD) - New Heads/Headgaskets with ARP studs, Air Silencer Delete, 70mm MAF, Plasti-dipped Matte Black with a Silver Metalflake Overlay, Muffler Delete, some LED's, 30.233 MPG for high MPG average!
2006 Jeep Wrangler 4WD (fun vehicle/backup DD) - 4.0/6spd - too many mods to list.
Associated Panthers:
Father's 1994 Ford Crown Victoria - Stock, 45,000 miles.
Sold in 2007 - 1987 Mercury Grand Marquis LS "Grandpa Special" 2 door.
http://www.cardomain.com/ride/2128327 -
Yeah, that whole idea of 4 tips sounds bad to me. The idea is hijacked from airplane spark plugs. It was passed in a similar form many years ago. An older guy I knew showed me a plug that looked eerily like a +4 that he used to run in a 1958 Oldsmobile. Maybe if you had a whole crapload of ignition power that could actually fire those it would work, but not our stock ignitions. Platinum actually doesn't conduct as well as copper does anyway, so it requires more oomph to fire. I run standard Autolite platinums in my car with good results. They run fine, aren't really expensive, and have held up OK.86 Lincoln Town Car (Galactica).
5.0 HO, CompCams XE258,Scorpion 1.72 roller rockers, 3.55 K code rear, tow package, BHPerformance ported E7 heads, Tmoss Explorer intake, 65mm throttle body, Hedman 1 5/8" headers, 2.5" dual exhaust, ASP underdrive pulley
91 Lincoln Mark VII LSC grandpa spec white and cranberry
1984 Lincoln Continental TurboDiesel - rolls coal
Originally posted by phayzer5
I drive a Lincoln. I can't be bothered to shift like the peasants and rabble rousersComment
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Thanks for the advice, but I don't know if that's it - I'm not a mechanic or anything, but the fact that the problem only occurs while in drive, idling with the brake on (like at a stop light or sign) makes it seem unlikely that the spark plugs have anything to do with it. Even if I'm in park with the car idling it's fine, and when actually moving forward/backward it doesn't present itself either. The only thing that makes me think they could be related is that it got worse after I changed the plugs/wires...maybe I knocked something else loose or something and didn't notice...89 Grand Marquis LS with 107K miles (as of 1/13/07). As proof of my undying love, I've invested:
- New exhaust
- Front brakes
- Rebuilt tranny
- New vinyl top
- Alternator & Battery
- And still going.Comment
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So it only does it when you have the brakes pressed?
Could be a booster problemComment
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Good call
Yeah I hadn't thought of that, thanks! It *is* only when I have the brakes pressed.89 Grand Marquis LS with 107K miles (as of 1/13/07). As proof of my undying love, I've invested:
- New exhaust
- Front brakes
- Rebuilt tranny
- New vinyl top
- Alternator & Battery
- And still going.Comment
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I had a leaky brake booster before and it ran rough all the time. Actually braking improved the idle..2000 Grand Marquis LS
2000 F150 XLT 6 inches of lift.
1987 Bill Blass Mark VII - Sold
1985 Mercury Grand Marquis Colony Park- SOLD. to a little old lady
Mercury Owners Group member
Save The Whales, Restore an Old Station Wagon!!Comment
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i've heard bad things about those +4 things. I use the basic cheap autolite copper plugs and they are awesome for a stock 302 with an HO conversion1989 Lincoln Town Car - "Anabelle" - Original block, .030 over with SpeedPro pistons, rods fitted with ARP hardware, FRPP +volume oil pump, GT-40 3bar heads, Crane 1.72 rockers, 89' Fox cam, 93' Cobra lower intake, Explorer upper and 65mm TB, 93' Lightning EGR spacer, K&N intake kit from a 4.0L Ranger, 19lb/hr injectors w/ 87 Mark VII ECM, cat/smog deletes, Big Brake conversion, 3.55 K-Code Trac-Lok/Disc brake rear axle, CVPI LCA's w/1" sway bar in rear, wagon front sway bar, BBK 2.5" off-road H-Pipe, Flowmaster super 40s, HPP wheels, 3G alternator w/LMR.com wiring kit, gear reduction starter conversion, Best 1/4 time: 16.0 @ 85mph.Comment
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All you need is a single electrode, 4 is WAY overkillComment
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We will not use the four tip plug....too many issues like you have...As for the problem when you step on the brakes....yes sounds like a booster ....but it is hard to diog via the internet....need my xray specs--o-o--President He Man Woman Haters Club
Life should not be a journey to the grave with the intention of arriving safely in a pretty & well preserved body,But rather skid in broadside,Thourghly used up totaly worn out & loudly proclaiming...WOW WHAT A RIDE!!!
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