Could it be just a miss?

[woodly1069]

I was wondering if anyone can help solve a strange problem. My 2001 4.6 seems to run great when cold but as it warms up I seem to have an inconsistent miss at SOME stops. The car will idle slower and sometimes try and sputter, then the computer will speed things back up to normal. The real problem occurs while riding down the road under load. When I'm on the acellerator lightly, things are fine; when I step on the gas the thing wants to fall on it's face before the RPM's get up, then of course, it's a rocket! I have changed the plugs, cleaned the K&N air filter and installed a new fuel filter; I have even tried some good Lucas injector cleaner with no help. I sure hope it has nothing to do with the computer because I have no Service Engine light illuminated, the car must think everything is perfect, but how? Could it be the fuel? Everything I have read says that I can run 87 octane and that's what I have in the tank currently. Any ideas are surely welcome. Thanks in advance...

 

[2000fordstanggt]

I was wondering if anyone can help solve a strange problem. My 2001 4.6 seems to run great when cold but as it warms up I seem to have an inconsistent miss at SOME stops. The car will idle slower and sometimes try and sputter, then the computer will speed things back up to normal. The real problem occurs while riding down the road under load. When I'm on the acellerator lightly, things are fine; when I step on the gas the thing wants to fall on it's face before the RPM's get up, then of course, it's a rocket! I have changed the plugs, cleaned the K&N air filter and installed a new fuel filter; I have even tried some good Lucas injector cleaner with no help. I sure hope it has nothing to do with the computer because I have no Service Engine light illuminated, the car must think everything is perfect, but how?Any ideas are surely welcome. Thanks in advance...

maybe a bad cop? also, do you have a tune installed?

 

[woodly1069]

what's a COP and how do I know if it's bad? I bought the car second hand and I'm not sure how to find out about a different map. I did think about it and the car does have flowmasters so it's a possibility...

 

[snidehockey]

COP = Coil on Plug

these stupid things...