Engine Misfire, Need Help
Thread Starter
Intermediate
Joined: Sep 2000
Posts: 32
Likes: 0
From: Austin, TX USA
Engine Misfire, Need Help
On the way home from an all day trip in my 98 Corvette Vert, the engine started misfiring badly. It would barely idle in neutral (automatic) with the AC off. I limped home, and of course the "Check Engine" light was on. I checked the onboard diagnostics and found code PO300-Engine misfire detected. Duh, I obviously new that. I do not have a scanner so don't what cylinders are causing the code. I checked all the vacum hoses first and didn't find anything. Then I checked the fuel injector fuses and found the #1 fuse 22 blown. The service manual says this fuse serves the injectors for cylinders 1, 5, 7 & 3. I replaced the fuse and started the engine, but the same problem was still present, and the fuse was blown again. I assume I must have a shorted injector or wiring to one of the injectors.
Has anyone had a similar problem that might give me some help?
Has anyone had a similar problem that might give me some help?
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
Check the resistance across each injector on that side, sounds like one might have shorted out and is causing the fuse to blow. Just pull the clip and check with an ohm meter.
Safety Car
Joined: Feb 2002
Posts: 3,726
Likes: 368
From: Montoursville Pa
Originally Posted by rapidrobert
Thanks for the input. I have checked the injector wiring that I can get to, and it all looks good.
Thread Starter
Intermediate
Joined: Sep 2000
Posts: 32
Likes: 0
From: Austin, TX USA
Engine Misfire, Need Help
Thanks for the latest two inputs.
I will check each injector with my ohm meter.
I will also check the harness at the back again. It sure is a little tight.
You guys are great. Thanks for the help.
I will check each injector with my ohm meter.
I will also check the harness at the back again. It sure is a little tight.
You guys are great. Thanks for the help.
Thread Starter
Intermediate
Joined: Sep 2000
Posts: 32
Likes: 0
From: Austin, TX USA
Engine misfire, Need help
Well, I checked the resistance on all injectors, and it was the same for all of them. So I continued to check the wire harness at all the sharp bends, moving it around etc., but couldn't find any evidence of chaffing or damage. However, I replaced the fuse and it didn't blow, and the engine is running fine. Now I presume I have an intermittent problem somewhere in the harness, but have no idea where it is. I'll continue looking, but may have to remove the harness which, obviously, I didn't want to do!
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Thread Starter
Intermediate
Joined: Sep 2000
Posts: 32
Likes: 0
From: Austin, TX USA
Engine Misfire, Need Help
Just thought I would update where I am.
I've checked the wiring harness even after pulling the intake manifold, and can not find any evidence of rubbing or damage. Also checked resistance of the wiring from fuse 22 (the one that blew), and there is no evidence of a short.
It is running fine at the present, but I just don't know what I did to correct the problem, and I wonder when it's going to happen again!
I've checked the wiring harness even after pulling the intake manifold, and can not find any evidence of rubbing or damage. Also checked resistance of the wiring from fuse 22 (the one that blew), and there is no evidence of a short.
It is running fine at the present, but I just don't know what I did to correct the problem, and I wonder when it's going to happen again!
Le Mans Master
Joined: Nov 2002
Posts: 7,179
Likes: 2
From: Charlotte, NC
Originally Posted by rapidrobert
Just thought I would update where I am.
I've checked the wiring harness even after pulling the intake manifold, and can not find any evidence of rubbing or damage. Also checked resistance of the wiring from fuse 22 (the one that blew), and there is no evidence of a short.
It is running fine at the present, but I just don't know what I did to correct the problem, and I wonder when it's going to happen again!
I've checked the wiring harness even after pulling the intake manifold, and can not find any evidence of rubbing or damage. Also checked resistance of the wiring from fuse 22 (the one that blew), and there is no evidence of a short.
It is running fine at the present, but I just don't know what I did to correct the problem, and I wonder when it's going to happen again!
Good Luck...
-=Rick
