Got a 2003 gt with intake, throttle body, plenum, 4.10's, diablo tune, new injectors I think there 30lbs, magna flows with x pipe.
I just started noticing my car gas mileage is going to crap. I think it has been for a month now but I just didn't notice. But reciently it has just plundered. Tonight im gonna check my plugs and see what they look like but I donno.
Symtoms: Rough idle, it will jump up and down about 500 RPM. Hard starts some times like it studders like turns a couple times before it kicks on.
In the exhaust if you get down there and listen to it you can here it going going going then it will hick up like it's slightly missing in one cyclinder.
It does have that Diablo tune on it and when I first bought it I didn't know it did. So it is tuned to 91 octane but I ran about 7 to 8 tanks of 87 through it so. I don't know if it is my timing or my plugs or what, but its kinda of messed up. But I still got good power and it only starts bad like that once and a while so.
UMM some other things that can help are its only got 46,000 miles on it. I don't beat it up really bad but I do drive it spiritually.
Got a 2003 gt with intake, throttle body, plenum, 4.10's, diablo tune, new injectors I think there 30lbs, magna flows with x pipe.
I just started noticing my car gas mileage is going to crap. I think it has been for a month now but I just didn't notice. But reciently it has just plundered. Tonight im gonna check my plugs and see what they look like but I donno.
Symtoms: Rough idle, it will jump up and down about 500 RPM. Hard starts some times like it studders like turns a couple times before it kicks on.
In the exhaust if you get down there and listen to it you can here it going going going then it will hick up like it's slightly missing in one cyclinder.
It does have that Diablo tune on it and when I first bought it I didn't know it did. So it is tuned to 91 octane but I ran about 7 to 8 tanks of 87 through it so. I don't know if it is my timing or my plugs or what, but its kinda of messed up. But I still got good power and it only starts bad like that once and a while so.
UMM some other things that can help are its only got 46,000 miles on it. I don't beat it up really bad but I do drive it spiritually.
THANKS!
with the rough idle: that was happening to me about a month ago. after i really diagnosed the problem, i found out that it was my ignition plugs and coil. quic fix but will cost around 300. more or less. the exhasut: maybe a leak? best of luck to ya..
with the rough idle: that was happening to me about a month ago. after i really diagnosed the problem, i found out that it was my ignition plugs and coil. quic fix but will cost around 300. more or less. the exhasut: maybe a leak? best of luck to ya..
How many miles did you have on yours? But yea thats what there telling me $360.
well mustangs aren’t really known for there awesome fuel mileage lol but do u have actual numbers for your mpg that would probly help. also in the future you should try to check your mialage when you fill up your tank. i check it everytime i fill up and if i notice i have an avrage of 19 to 21 mpg and one time its like 14 or a low number you know you have a problem.
__________________
01 red gt 5 spd, bassani catback, short shifter, bbk CAI, 3.90's, steeda sport springs, cobra R rims 17x9 255/40 front 275/40 rear and as long as the money keeps comin so will the parts ;p
spark plugs, throttle body, air filter, MAF sensor, fuel filter, heavy right foot.
Adjust, replace or clean these and you should see your MPG improve
__________________
2007 Mustang GT Vert. Clutch Delete option 271.1/278.9 AFM's Unofficial "Mini-Mod King!"(Mods in profile) There are 3 things i learned from life *quote from the Bucket List*
-Never pass up a bathroom
-Never waste an arousal (edited for forum)
-Never trust a fart
01 red gt 5 spd, bassani catback, short shifter, bbk CAI, 3.90's, steeda sport springs, cobra R rims 17x9 255/40 front 275/40 rear and as long as the money keeps comin so will the parts ;p
Your car came stock with 19lb. injectors, if you stepped up one you would have 24lb. injectors. But for the mods you have, I just can't see 30lb. injectors unless your over 400HP. And if you do have 30lb. injectors, that alone will kill your fuel economy. With 30lb. injectors I hope you replaced the fuel pump to feed them. I think you have too much over kill, for the mods you have in your motor and there's no way your even close to 400HP without changing the heads and cams. Also if your running anything less then 93 Octane, is enough to cause your problems 87 Octane is for lawn mowers not modded Mustangs. I can tell you don't know much about cars, just by the mods and fuel your using. It would be a little better, if you could tell me exactly what's been done to the car, Mike. SCT Tuner.
Your car came stock with 19lb. injectors, if you stepped up one you would have 24lb. injectors. But for the mods you have, I just can't see 30lb. injectors unless your over 400HP. And if you do have 30lb. injectors, that alone will kill your fuel economy. With 30lb. injectors I hope you replaced the fuel pump to feed them. I think you have too much over kill, for the mods you have in your motor and there's no way your even close to 400HP without changing the heads and cams. Also if your running anything less then 93 Octane, is enough to cause your problems 87 Octane is for lawn mowers not modded Mustangs. I can tell you don't know much about cars, just by the mods and fuel your using. It would be a little better, if you could tell me exactly what's been done to the car, Mike. SCT Tuner.
I just used the 87 oct 7 or 8 times the dealership said it would be fine. Then when I got to jacksonville it started ping really bad in 5th so I put 91 back in it with a thing of octane booster. That fixed that problem a little.
Whats been done to it. It has a typhoon intake, 75mm throttle body and plenum. The injectors are pink I thought they were 30lbs. It has a diablo tune on it, but the guy that had it before me is sending me the tuner so I dont know how he mapped it yet. Other then that it has 4.10's and magna flows. Thats about it. The car is as is, everything thats on it was like this when I bought it. The dealership didn't tell me it had gears I could just tell by how it was reving in the gears. I found out it had a tune when I called the guy a month later.
if the injectors are not stock then the MAF must be re-calibrated for them. if it isn't then you could be running very very rich causing the terrible fuel mileage.
__________________
Procharged 2002 Mustang GT 5 Speed 351rwhp 353rwtq at 10psi
Next summer looking to go with:
Bilstien shocks + struts, Lowering springs (brand still TBD (any suggestions?)), MM CC plates, front + rear sway bars, subframes, and upper and lower control arms.
Time to make the pony ride some rails
if the injectors are not stock then the MAF must be re-calibrated for them. if it isn't then you could be running very very rich causing the terrible fuel mileage.
Oh yea the MAF has definitally been redone. It ran great up until this week. Like when I first bought the car I was getting a good 19MPG in the city 21MPG high way. Over all depending on the way I drove it. I was getting 220 miles to a tank. But this week I dropped to 171.... So im gonna start small and work my way up.
only 220 to a tank i get 280 290 and i average about 19 20mpg i would do better if i could keep my foot out of it but thats not why i bought a mustang
__________________
01 red gt 5 spd, bassani catback, short shifter, bbk CAI, 3.90's, steeda sport springs, cobra R rims 17x9 255/40 front 275/40 rear and as long as the money keeps comin so will the parts ;p
Bad mpg! Help!!!!!! 
(Mods in profile)
