1998 Pontiac Grand Prix Engine Stutter/Hiccup

1998 PONTIAC GRAND PRIX
14,370 MILES • 6 CYL • 2WD • AUTOMATIC
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ANDERP70
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I have a 98 Grand Prix 3.1L V6 w/ 143,700 mi.

For the past 3 weeks I've noticed that while driving between 45-55 mph, my entire car would jerk about 4 or 5 times real quick and then stop. It wasn't just the steering wheel or wheels, but the entire car would stutter and then work fine. (It almost felt like going very slowly uphill in an ATV and having the wheels slip and catch several times in about 2 seconds time). This would happen about twice a week and only once a day.

In the past week, it has increased in occurence and become a little more harsh. It now does it between 40 and 60 mph (once at 30 mph going uphill) and I've noticed that when I press on the accelerator while it does it, the car wont respond and the RPMs stay around 1500-1800 (this is where my RPMs run at 55mph). If press down a lot on the accelerator, the stuttering stops and the car accelerates nicely. It also stops stuttering if I take my foot off the gas completely.

Never any major engine trouble. Recently had water pump and fuel filter replaced.

Taking it to a mechanic on Monday.
Mar 13, 2009 at 12:15 AM
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MMPRINCE4000
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Is your check engine light on?
Mar 15, 2009 at 8:35 AM
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ANDERP70
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Yes it is. It has been on for quite some time. A few years in fact. Everytime I had the codes read they would fix what the problem was and then the light would be reset. It would stay off for about 15 min of driving and then come back on. The last codes I had read off of it were MAF sensor out of range and something about the EGR valve.

I have a strong suspision that the MAF is the problem with the misfires and that code supports my suspision.

I also don't think its the TCC solenoid b/c the car is doing it at about 30 mph now too and not when I press on the brake. I had platinum spark plugs put in about 3 years ago and had a full tune up. I know I need a new one....
Mar 15, 2009 at 12:26 PM
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MMPRINCE4000
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The MAF sensor measures the volume of air going into engine, fuel trim and ignition are based on the MAF reading.

If MAF is out of range, it will cause hesitation, hard starting, jerking, bucking etc.

EGR flow, either too much or too little, can also contribute to the above problems, it can also cause the engine to stall if it flows at idle.

Try using a MAF cleaner on MAF, spray as directed and do not touch wires, remove and clean EGR valve, base and pintle.

If this does not solve problem, then replace MAF and EGR.
Mar 16, 2009 at 7:40 AM
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ANDERP70
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Saw the mechanic today. SIMPLE FIX!!!

The connector in the boot of the spark plug wire was shorted out on Cylinder 2 causing misfires. The check engine soon light was on b/c a mechanic from several years ago installed my EGR valve backwards!??!??!?!

$180.00 and its running beautifully.
Mar 16, 2009 at 7:47 PM
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MMPRINCE4000
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Great news, thanks for using 2carpros.
Mar 18, 2009 at 7:03 AM