Ford Mustang Forum banner

1 - 13 of 13 Posts

·
Registered
Joined
·
183 Posts
Discussion Starter #1
Hey Guys,
My “Check Engine” light has been on for some time now with no actual problem. When I got the computer read it was a miscellaneous misfire. Now, 6 months later, it is getting worse. I can actually feel a power lag and the light flashes for at most 20 secs. And then I can feel the misfire stop. I just got the codes pulled again and it came up with 9 codes:

Miscellaneous Misfire
Cylinder #1 Misfire
Cylinder #2 Misfire
Cylinder #3 Misfire
Cylinder #4 Misfire
Cylinder #5 Misfire
Cylinder #6 Misfire
Cylinder #7 Misfire
Cylinder #8 Misfire

The first mechanic I took it to read the codes the first time said it was probably my ignition booster killing my coils. The second mechanic the read all 9 of the codes thinks it it my injectors, because if the coils are a work or no work parts. Once they stop working the stop for good. Anyone have any ideas? I don’t want to spend a **** load on parts when I am selling it at the end of the month. I just want it to run good and not have the Check Engine light on.
Just to think this all started with a burnout… damn burnout!!!
 

·
Registered
Joined
·
5,907 Posts
When you did the burnout, did you let the engine bounce off the rev limiter?

Pull the plugs and read them first thing. Also check fuel pressure at the fuel rail. Do a compression test. A misfire can be caused by a few different things, you need to start narrowing down the possibilities.
 

·
Registered
Joined
·
183 Posts
Discussion Starter #3
No when I did the burnout it never did hit the rev limiter... when I had the first mechanic read the codes he did a compression test and I changed the spark plugs right before taking it in… I will look at the fuel rail tonight… what do I need to be looking for in it? I never have had to check a fuel rail before. Just look for buildup or blockage?
 

·
Registered
Joined
·
5,907 Posts
You need to put a fuel pressure gage on the fuel rail and see what it reads at idle, then blip the throttle and see if it drops.
 

·
Registered
Joined
·
183 Posts
Discussion Starter #5
what i have been noticing is then when it is at idle it works fine and drives fine... it’s when I go to give it more gas and keep the peddle in s curtain area like when going up a steep hill is when it starts to misfire
 

·
Registered
Joined
·
53 Posts
My 98 Gt was doing something similar to that and I found that my plugs had fouled. What condition are your spark plugs in?
 

·
Registered
Joined
·
133 Posts
also check your PLUG WIRES. wait till dark or park in a dark garage and look for any visible spark around the boots and the coils. If you see any, replace your wires, i recommened a set of steedas or taylors:bigthumbsup
 

·
Registered
Joined
·
183 Posts
Discussion Starter #8
The Spark plugs are new as of 6 or 7 months ago... i pulled them out last night and they looked fine other than a little dark from the misfires. also i did look to see if i could see any spark from wires and i didn’t... I'm leaning towards a fuel problem... my next task is to test the fuel pump even though when I do step on the gas it doesn’t create the problem. Its only when I am giving more gas than usual for a period of time so I’m thinking it has to be a fuel rail or injectors…
 

·
Registered
Joined
·
32 Posts
My 97 Gt did the same thing and it was the plug wires, I did the "looking in the dark" for spark jump but my engine wasnt under load so simply revving it wasnt getting the jump. I replaced the wires with FMS wires problem gone, just a thought.
 

·
Registered
Joined
·
997 Posts
Do you have an aftermarket tune on it? I had a similar problem with my '02 (random multiple misfire code along with misfire codes for cylinders 1, 3, 4, and 5 when driven hard). I rotated COP's to see if they were the cause but the misfires didn't follow them, and I also changed the plugs, but they weren't the culprit either. The guilty party ended up being the Hypertech that I was using to correct the speedometer (and the 93 tune just for kicks and giggles). A guy I work with explained it as faulty programming or an error in the programming that finally surfaced (I had ran the Hypertech for over a year without any issues). May not be the case for you car but I figured I'd mention it as it seems you've already ruled out most of the basics. Good luck.
 

·
Registered
Joined
·
183 Posts
Discussion Starter #11
Ya I never put any kind of tune on it... it has all forged internals, mass flow intake, lighted pulleys, and ignition booster... I thought it was the booster at first killing my coils but I unplugged it with no change in performance... Thanks for your help
 

·
Registered
Joined
·
7,401 Posts
what kind of "booster"?

It's possible that it has killed your coils already, and unplugging it isn't going to do any good.
 

·
Registered
Joined
·
183 Posts
Discussion Starter #13
Sorry i havnt had time to look under my hood at it... between work from 7 to 4 and school from 5 till 10 kinda been busy haha... all i can remember is its black (not like that helps any) dose anyone know how to test the coils or injectors?
 
1 - 13 of 13 Posts
Top