LS1 Misfire
Thread Starter
Teching In
Joined: May 2009
Posts: 1
Likes: 0
From: Budd Lake, NJ
LS1 Misfire Hi, my car started to misfire randomly at idle. Eventually the SES light came on and it's a PO300 code (random misfire). Now it sounds like it's running on only seven cylinders. I checked and there was voltage from all eight coil packs. My next guess is a bad spark plug or possible fuel injector. I'm leaning toward a bad spark plug. Any suggestions on what else it could be?
Also, what is a good replacement spark plug for my car? I don't race it and it's stock.
Thanks, Mike
Also, what is a good replacement spark plug for my car? I don't race it and it's stock.
Thanks, Mike
Most commonly it ends up being a broken valve spring on cars that have aftermarket springs, but if you are sure your car is bone stock, then you are heading in the right direction.
TECH Fanatic
Joined: Aug 2006
Posts: 1,407
Likes: 63
From: Knappa, Oregon
Multiple Random Misfire. I would change the spark plugs and wires. If that isn't the problem at least you have eliminated a common source of random misfire and done some regular service.
If you are driving it as a street car, like I do, I would suggest putting in the AC Delco Iridium plugs it came with and some after market heavier plug wires, like Taylor or MDS.
Many people here use NKG plugs with great success. I don't recall which ones but someone should be along shortly to say.
If you are driving it as a street car, like I do, I would suggest putting in the AC Delco Iridium plugs it came with and some after market heavier plug wires, like Taylor or MDS.
Many people here use NKG plugs with great success. I don't recall which ones but someone should be along shortly to say.
TECH Enthusiast
Joined: Mar 2009
Posts: 522
Likes: 0
From: West Chester, PA
Multiple Random Misfire. I would change the spark plugs and wires. If that isn't the problem at least you have eliminated a common source of random misfire and done some regular service.
If you are driving it as a street car, like I do, I would suggest putting in the AC Delco Iridium plugs it came with and some after market heavier plug wires, like Taylor or MDS.
Many people here use NKG plugs with great success. I don't recall which ones but someone should be along shortly to say.
If you are driving it as a street car, like I do, I would suggest putting in the AC Delco Iridium plugs it came with and some after market heavier plug wires, like Taylor or MDS.
Many people here use NKG plugs with great success. I don't recall which ones but someone should be along shortly to say.
