wats up guys, ive been using and buying parts on american muscle for about 2 years now. i have a 2001 mustang GT with a JLT ram air, MAC prochamber O/R and flowmaster american thunder mufflers. ill post a few pics of the car when i actually get a chance because college does own my life right now -_-

BUT ANYWAYS!!! now to the juicy stuff. ive been having a problem now for the past year and ive been to different mechanics. they all have had different opinions on what the hell is wrong with my car. and its kind of hard to explain. so here goes my best shot.

lets say on a cold start up the car turns on just fine. about 5 seconds later, the exhaust gets like a little putt putt to it. then it returns to normal idle. and back again to the putt putting. the RPM's do certainly drop about 100 or so when this does happen and you can definitly feel it when your in the car idleing. ALSO it does happen quite a bit more with the AC on at max AC. all at random times tho, the car could be cold, or it can do it after a 20 minute drive. now if this was just idle i really wouldnt care, but it does it A LOT also when im driving and hitting the gas hard. the car has been kept in great shape since i have had it too. im actually chanaging the whole EVAP system becuase ive been getting a check engine like with that code in it. but i doubt that is it.

when i hit the gas on my car, even when taking off, it just doesnt have power taking off and the "put putting" feel is there for just a little, LIKE IF SOMETHING IS CLOGGED! and just enough power it will go away. but even lets say when i hit my gas hard at 3500 rpms, i will get pinned back, i would stop getting pinned back for about maybe 2 seconds or less, get that "putt putting" feeling and then the car would gain all HP back and pin me back again. its just dam wierd.

any at all ideas will greatly be appreciated. i hope others have occured this problem. i have about 78,000 miles on it if that helps. let me know guys!! dont let me down!!!

edit: i have also brought my car to the dyno, 242 HP 281 TQ, and i have a slipping clutch. not sure if thats the HP i should be gettiing. with the mods.

 

full tune up, replace all plugs and filters and clean the IAC and EGR valves out. Then unplug the battery for 10 minutes to clear the codes and see what you get.

 

wires too?

 

awesome thanks guys, after i get the whole EVAP system replaced i will try that stuff. i'll let you guys know. any other ideas are appreciated!!!

 

99+ dont have spark plug wires.

 

they have coil boots which can get cracked and allow moisture in causing a miss. I've had this problem before

 

+1 on the tune up; try new plugs and change the fuel filter

 

blonde moment.

 

awesome guys ill try all of that, i have asked others around and they have told me about the IAC valve. the fuel filter was changed, dirt came out of that -_- i was surprised how the car was kept before i got it. ill update you guys and let you know how it turns out! hopefully my problems wont be anyone elses in the future. thank you!

 

Sounds crazy, but make sure your AC is fully charged. When the compressor keeps cycling on and off, it makes the car idle rough. Happened with my car...RPM's kept going up and down at idle...was VERY annoying.

 

posted this in another spot, but also try checking and cleaning your MAF.

 

I had a very similar problem with my 88 Bronco. Had the same symptoms as your stang. We got a couple o' bottles of fuel injector cleaner and that helped some. Then change the fuel filter and that fixed it. Hope this helps.

 

the other week i used some fuel injector cleaner. it did help, but the next day it was back to its stupid self. i did change the fuel filter and A LOT of dirt came out of that. went to my buddies work at firestone and they cleaned the throttle body and then inserted some cleaner to which i think was my plenum (not sure didnt pay attention) while having the car run at about 2000 rpms. looked like my car had an IV lol. it was supposed to clean the engine out and fuel injectors and so forth. it helped that day but the next day it was back to **** again. its really wierd. i dont know what to do with the car.

 

haha they seafoamed that ****.

 

if your getting alot of crap in the fuel filter, I'd be checking the sock on the fuel pump in the tank and sea if its clogged or if the tank has rust in it, todays Ethonal fuels draw mositure outta' the air and if you dont keep the tank full (kinda' hard to-do) the inside of the tanks can build-up wth surface rust.....so I'd drop the tank (and dont forget to replace the grommet) and inspect the insides and prob replace the fuel pump while your in there.....

 

WHAT?? Evap sysem replaced?? Sounds like a bad coil. Do yourself a favor and this will save you a lot of time and $$. Take it to a qualitifed mechainc that knows what they're doing and let them fix it. Trust me, I see stuff like this all the time!!

 

WATS UP GUYS!!!!!!! took my car to Difeo ford over here in jersey and all it need was new spark plugs and coils. the car is running with awesome power and soon to get a 93 pump gas tune.

thanks for the help and support from everyone!!!!!!