• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

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

G

gtpmaddi

New member
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! :D
 


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.
 
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.
 
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?
 


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 :)
 
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 :th_jester:
 
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...
 


You must log in or register to reply here.
Back
Top