LonghornGT

Hey all, first post here, glad I found this site. I have a 04 GT Conv w/29,000 miles (use it for work)
My performance is slipping some and need a little advice. Off the line or from a stop light it is real sluggish, really have to put the pedal down to get her to jump, I'm going to change the Fuel Filter this week, I will also be changing the transmission filter, will check the rear diffs, also will probably go ahead and change out the plugs and wires, just not sure which ones to go with, taylor, NGK ???
At this point I have no mods except a drop in K&N filter, Is there anything else I should check/change, will cleaning out the butterfly/throttle body be okay. I know this is alot of questions, sorry about that, any help would be most appreciated, OH YES, I have had the rotors replaced twice now by Ford and the fuel pump once, the car sometimes doesnt want to turn over when starting up, Ford out of desperation just replaced the fuel pump, but still having the same startup problem, trying not to leave any usefull info out here. Thanks again.

Dan04COBRA

Automatic? 5 Speed? Stock gearing?

You should go ahead and change the fuel filter and go through the plugs, coilpacks too if you want..

Is your MAF gummed up at all?

LonghornGT

Sorry, it's stock automatic, I will pull the mass air flow sensor and clean it up, not sure what to use on that to get it clean, I read something somewhere about seafoam??? Can you suggest what coilpacks to replace with and plugs/wires.

team801

Personally I would do the Fuel Filter, clean the K&N, Change the plugs (NGK's are decent).......I wouldn't do the coilpacks since it will cost you too much and you won't notice a performance increase.

Dan04COBRA

I would suggest using isopropyl alcohol sprays, you can find these at most autoparts/electrical stores.

Spray some on a cotton swab (if you can't get the wires clean from that alone). Be EXTREMELY careful...

As for plugs/coil packs, stock replacements will work just fine. There isn't much of a need to upgrade to anything 'high performance' assuming you are running a fairly stock GT.

LonghornGT

thanks to the two of you, I just went and picked up my filter and that tool needed to get the old one off, now where on this 04 do you take the pressure out of the line???

Derf00

Two ways to do this. One is pull the fuel pump fuse and then start the car. It will die in a few seconds. The second way (which is recommended in repair guides and by the dealer) is to disconnect the Fuel Pump Cuttoff Switch located near the Driver side taillight. It might be the passenger side. Start it up and let it 'run out of gas'. I would go a little further and do one of the above then crank it for a few more seconds to relieve the pressure as much as possible.

When you are done changing the filter, put the fuse back or plug the cuttoff switch back in, put the key to the 'On' position until you hear the fuel pump stop, then try to start the car. Don't turn it over for more than 30 seconds at a time or you could burn out the starter.

Also, I'm not sure of the 4.6 but there may be an air relief valve under the hood in-line with the fuel rail. This valve helps to get air purged out of the fuel system. The V6's don't have it but I think I remember reading somewhere the V8s do.

LonghornGT

Derf00, thanks for the reply, I will have to admit I am a virgin when it comes to working on mustangs, when you say there is a cutoff near the back tail light exactly where is that, in the trunk??? Dont laugh, but I have a hard time paying Ford 175.00 to do this, it only cost me 6 for the filter and 5 for the tool.

StickShifty

open the trunk, look down and to the left, its behind that matted panel. the fuel cutoff switch is for when u get into a crash, so the car does not **** fuel everywhere.

LonghornGT

Thanks StickShiftyGT, it's going to be around 95 today, but we have a cool spell tonight and tomorrows high is 70, will go at it in the a.m. after all has cooled down