Miss Fire Problem
Thread Starter
7th Gear
Joined: Nov 2007
Posts: 7
Likes: 0
From: Fort Worth TX
Miss Fire Problem
I'm a newbie, tried searching, but didn't see what I was looking for. I have an 89 C4 with a stock L98. I have a nice valve cover leak and decided to change out the plugs, wires, rotor, cap, and coil while I was at it. Everything was running as it should be prior to the changes. Now I have a slight miss while in idle, and it is really missing when I'm driving, especially if I attempt to keep a constant speed. I've since re-checked and replaced everything, and still have the problem. While re replacing the spark plugs, I noticed that #2 and 4 didn't appear to be firing nearly as well as the rest.
Any ideas?
Any ideas?
Race Director
Joined: Jun 1999
Posts: 14,924
Likes: 9
From: Merritt Ils Fl
Obvious question is did you have the miss before you changed parts? If no then you likely didn't do something right. My first guess would be two plug wires swapped. Don't laugh, some of the very best have done it. While you are checking make sure the plug wires are fully seated, both in the cap and on the plug. I would also ohm the injectors as gw962 suggested.
Drifting
Joined: Jun 2005
Posts: 1,426
Likes: 1
From: brookville pa.
missfire
tell me about it. that is what i did firing order 18436572 i had it 18346572, car was backfiring thru exhaust changed to correct order bingo sounds healthy again so make sure wires are on correctly
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Originally Posted by wrnglrwrercpe
Everything was running as it should be prior to the changes. Now I have a slight miss while in idle, and it is really missing when I'm driving, especially if I attempt to keep a constant speed.
RACE ON!!!
Racer
Joined: Oct 2003
Posts: 491
Likes: 1
From: Owasso OK
Obvious question is did you have the miss before you changed parts? If no then you likely didn't do something right. My first guess would be two plug wires swapped. Don't laugh, some of the very best have done it. While you are checking make sure the plug wires are fully seated, both in the cap and on the plug. I would also ohm the injectors as gw962 suggested.
I made that mistake a few months ago...drove me nuts trying to find the problem, turned out to be the obvious....wires swapped!
Thread Starter
7th Gear
Joined: Nov 2007
Posts: 7
Likes: 0
From: Fort Worth TX
lol.. yeah, I've checked the plug wires, and made sure they're seated good. Didn't have this problem prior to the changes, which is why it's frustrating. I've got no problems accelerating, but trying to maintain a constant speed it runs rough.
Thread Starter
7th Gear
Joined: Nov 2007
Posts: 7
Likes: 0
From: Fort Worth TX
After re-checking the plug wires, checking the fuel injectors, I decided to put back in the stock coil ( I had replaced the stock coil with an MSD 50K Volt coil), and that solved the problem!
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