Grand Prix GTP 3.8L V6 Supercharged Random Misfire Cylinder 3 PLEASE HELP

**gtpmaddi** · 04-19-2011

1998 Grand Prix GTP supercharged. Random misfire on cylinder 3 seems to only happen when accelerating through 3000 RPM's... If the supercharger kicks in before it hits 3000 Rpm's then no misfire at all and full boost. If not, car engine seems to shake a little and the SES light flashes. When this happens the boost gauge shows full boost, but little occurs and car has basically no power when this misfire happens. Used a code reader and it confirmed random misfire cylinder 3 only as well as traction control being stuck off. When I tried to look for the issue under the hood, found that the belt has been a bit chewed up (but only in one section) and the silver coil packs ignition header is corroded (only the header connecting to cylinder 3). Any help or advice that could shed a light on this misfire's cause would be greatly appreciated!

**sseilmnop** · 04-19-2011

Are you saying the #3 spark plug wire connection on the coil pack is corrodedand the misfire is on #3? Short term clean the connection see if it helps and long term get a new OEM coil pack because it will corrode again. MSD coil packs offer no benefit and are less reliable.

Get a new belt!

Lack of ABS and traction control is most likely a front wheel bearing going bad. The sensor is in the bearing. Don't buy cheap bearings they don't last much more than a year.

**BillBoost37** · 04-19-2011

The problem is on 3, the corrosion is on 3. Fix the obvious issue and go from there.

If your girl friend is hot, she's cheating on you.

**gtpmaddi** · 04-19-2011

thanks sseilmnop ! I'm getting a new belt, spark plugs/wires and OEM coil packs on Friday, and I'll check the bearings as well. Hopefully that clears things up. Also, is it really 100% necessary to fuel it with premium?

**Scottydoggs** · 04-19-2011

Originally Posted by gtpmaddi

Also, is it really 100% necessary to fuel it with premium?

yes

**sseilmnop** · 04-19-2011

Originally Posted by scottydoggs

yes

Yes to premium. They missfire on 87 and eventually destroy a piston destroying the motor. My mom could drive on 87 but she never pushes the gas pedal past 1/2.

**BillBoost37** · 04-20-2011

Originally Posted by gtpmaddi

Also, is it really 100% necessary to fuel it with premium?

There is another thread with a guy on his 3rd motor due to 87 octane. It's very necessary in boosted applications.

**gtpmaddi** · 04-20-2011

I wonder if that's what could have caused my misfire, I know the previous owner was running it on 87

**06gtSC** · 04-21-2011

i had a very similar issue, my car would shake and shudder on cylinder 5, turned out it was spark plugs and wires, and the previous owner ran regular oil, and regular 87 octane fuel, invest in syntehtic oil, and premium gas, your car will do you wonders

**EJOUIE** · 04-21-2011

Here is what you do to fix a single cylinder misfire.
1. Find a rock that is just small enough to fit into the cylinder
2. Buy a gallon of 99% Isopropyl Alcohol
3. Pour the alcohol into a bucket
4. Put the rock in the bucket so that it is completely submerged
5. Put the bucket in a freezer for 3 days (preferably with a full moon on one of the nights)
6. During the 3 days remove the heads from the engine
7. Here's the start of the tricky part. On the 4th day pull the bucket out and put the rock in the problematic cylinder
8. Reassemble the engine before the rock warms up. It has to be cold for this to work.
9. As soon as the engine is reassembled, fire it up and stomp on the gas so it hits the rev limiter then immediately shut of the engine
10. Remove the heads and the rock
11. Reassemble the engine
12. Realize that this is a joke

**gtpmaddi** · 05-11-2011

Ok, so I got new coil packs, wires and spark plugs. Even though the coil pack's connection on cylinder 3 was corroded, none of this helped any and we've still got the same misfire. Seems that it's not an ignition problem...

**EJOUIE** · 05-12-2011

I had a nasty single cylinder misfire a while back and a new pcm fixed it.

Thread: Grand Prix GTP 3.8L V6 Supercharged Random Misfire Cylinder 3 PLEASE HELP

Thread Tools

Display

Similar Threads

Random Misfire

From misfire at cylinder 3 to a open circuit on the fuel injecter at cylinder 5

Cylinder #1 misfire and random cylinder misfire

97 Grand Prix GTP with Intermittent #4 Cylinder Misfire

Random multiple cylinder misfire

Bookmarks