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Timing

R

redskinman73

New member
I just bought a 98 Grand Prix SE. This is the first Pontiac I have ever owned and the first vehicle I have ever owned that has a distributorless ignition and I am at a loss at the moment. I changed the plugs and wires and the car still has a rough idle and the rpms fluctuate while going down the road. anybody please help me. How do I reset the timing in this car?
 


It doesn't sound like timing. It sounds like a miss. It could be a bad coil pack, or clogged fuel filter/ bad fuel pump. It could be a bad crank position sensor though.
 
First thing would be to check all the wires then check all the plugs (Check for cracks in the porcelain). If those are good I would take two wires off the coil pack (that are next to each other) at a time and crank it over to see if it arcs between the two terminals on the coil pack to see if that is good. If you still can't find an issue I would keep going with the stuff above and possibly more.
 
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Thank you for all of your input I will check the coils and see if that is the problem. I will post my findings later today. As somebody above asked it is a 1998 Grand Prix with the 3.8 naturally aspirated. the "service engine soon" light is on.
 
Tell us what code it is then get back to us...

You can get it read at any local auto parts store for free.
 
Ok, I'll say it. Are you 100% sure you have the plug wires in the correct order? I mean don't just assume they are, find the order on here or in a manual and check them 1 by 1. It's not incredibly hard to swap 2 cylinders and have it run like junk. Happens quite often. Don't trust that the previous owner had them correct either.
 




Thank you all again for your input. I changed the plug wires and it runs awesome now. the code said cyl. 3 misfire so i cleaned all the plugs and changed the wires the car runs like a top now. anybody have any tips on fuel milage? the car already gets good milage I just wanna get the most out of it, I'm a college student lol. I'm sure some of you know how that goes. Any ideas will be greatly appreciated.
 
Well, since most of my driving is highway at or around 60-65mph, I can squeeze about 425 miles out of a full tank, and that is down to dangerously empty. Not sure what the MPG works out to, never did the math. Not sure on the city mileage.
 
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