Engine Misfire
Thread Starter
Melting Slicks
Joined: Feb 2002
Posts: 2,479
Likes: 17
From: Miami Fl
Engine Misfire
Got code PO300 HC, engine misfire- what are the possibilities? plug wires appeared tight? Vaccum line? spark plug? I cleared the code a few times now it is staying off, hope Ernie can look at it Monday!
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Go with the simple stuff first!
It sounds like you have a classic case of a bad plug or sparkplug wire. I had my headers installed and had the same problem. When you get the pop does the engine misfire. Check your dash and look for the check engine lite to flash. It it comec on and stays on and you pull up your codes you will see a (10 PCM 0300) code indicating engine misfire.
Here is what I found when I had to trouble shoot mine:
LOOKS NORMAL, RIGHT
[IMG]
[/IMG]
CLOSER EXAMINATION REVIELS:
[IMG]
[/IMG]
[IMG]
[/IMG]
On the other side I found this:
[IMG]
[/IMG]
[IMG]
[/IMG]
Your OEM wires should read between 250-750 ohms and the jackets and boots should be plyable and in tact.
Let us know what you find,
Bill Curlee
It sounds like you have a classic case of a bad plug or sparkplug wire. I had my headers installed and had the same problem. When you get the pop does the engine misfire. Check your dash and look for the check engine lite to flash. It it comec on and stays on and you pull up your codes you will see a (10 PCM 0300) code indicating engine misfire.
Here is what I found when I had to trouble shoot mine:
LOOKS NORMAL, RIGHT
[IMG]
[/IMG] CLOSER EXAMINATION REVIELS:
[IMG]
[/IMG] [IMG]
[/IMG] On the other side I found this:
[IMG]
[/IMG] [IMG]
[/IMG] Your OEM wires should read between 250-750 ohms and the jackets and boots should be plyable and in tact.
Let us know what you find,
Bill Curlee
Thread Starter
Melting Slicks
Joined: Feb 2002
Posts: 2,479
Likes: 17
From: Miami Fl
Thanks for the fotos Curlee! I don't really get a popping sound. I should know if it is something simple today. When I was getting the rough idle 4 days ago (I was in a parade with a sexy beauty Queen sitting on top of my open coupe and I was revving the car in neutral to get a good exhaust note for the very appreciative crowd), I pulled up the code for misfire about 10 times ( don't like to see that stupid check engine light so I kept clearing it). I know it's cylinder 1 from the scan that Breathless did. Hope it's not in the valvetrain/pushrod. Does anyone know what postion (when standing in front of the car) what the various #s of the cylinders are?
Thread Starter
Melting Slicks
Joined: Feb 2002
Posts: 2,479
Likes: 17
From: Miami Fl
So far plug, wire cyl #1 OK. Coils being checked now. Thanks for all the help so far guys (The search for engine misfire was very good). Does anyone know if blower cars (A4) are more prone to valve train problems?
Thread Starter
Melting Slicks
Joined: Feb 2002
Posts: 2,479
Likes: 17
From: Miami Fl
After switching the coils and taking off the valve covers it was determined that the problem is a bad injector. These are not that old, 10 months- 5,000 miles- 20 passes and 30 auto-x events. Ernie said that they're Lucas injectores 50# , any comments. The valvetrain was insoected- pushrods, rockers, springs looked OK? Getting an injector overnighted from California so I can get my baby back for Turkey Day.
