2003 t bird running rough

Just joined and need some advise please. I purchased a 2003 t-bird for my wife,new in 03. She loves the car, but we've had tons of trouble out of it. According to the Ford mechanics it's the computer. We've put 3 computers in it and finally they put a Lincoln one in and it's worked the best, but still doesn't work right. Engine runs very rough. It runs so rough it shuts off. Ford sent me a new computer, which I still have in the box. That's the history. Car has 36000 miles on it and other then the computer chages it's all stock. I've read the upgrades reccomend and were going to do them all. A couple questions. do I need a new computer use the one Ford sent me or leave the Lincoln one in it? On the Bola exhaust would it be better to put new headers on when we put the cat backs on? Also plan on putting the KN intake system and the suspension up grades on. If there any advice to be given I'd appreciate it. Am I missing anything. I would imagine will have this car for life. Thanks Rob Proffitt
 

j&d

Active Member
Just joined and need some advise please. I purchased a 2003 t-bird for my wife,new in 03. She loves the car, but we've had tons of trouble out of it. According to the Ford mechanics it's the computer. We've put 3 computers in it and finally they put a Lincoln one in and it's worked the best, but still doesn't work right. Engine runs very rough. It runs so rough it shuts off. Ford sent me a new computer, which I still have in the box. That's the history. Car has 36000 miles on it and other then the computer chages it's all stock. I've read the upgrades reccomend and were going to do them all. A couple questions. do I need a new computer use the one Ford sent me or leave the Lincoln one in it? On the Bola exhaust would it be better to put new headers on when we put the cat backs on? Also plan on putting the KN intake system and the suspension up grades on. If there any advice to be given I'd appreciate it. Am I missing anything. I would imagine will have this car for life. Thanks Rob Proffitt
Our '05 was running rough so I replaced all the plugs and coils at 41k and it runs perfect again. Every plug and coil I removed was checked for gap and cleanliness. I also ohmed each coil I removed and they all looked good. I never found out which one or ones were going bad but the car runs perfect again. Good luck. Let us know.
 
Just joined and need some advise please. I purchased a 2003 t-bird for my wife,new in 03. She loves the car, but we've had tons of trouble out of it. According to the Ford mechanics it's the computer. We've put 3 computers in it and finally they put a Lincoln one in and it's worked the best, but still doesn't work right. Engine runs very rough. It runs so rough it shuts off. Ford sent me a new computer, which I still have in the box. That's the history. Car has 36000 miles on it and other then the computer chages it's all stock. I've read the upgrades reccomend and were going to do them all. A couple questions. do I need a new computer use the one Ford sent me or leave the Lincoln one in it? On the Bola exhaust would it be better to put new headers on when we put the cat backs on? Also plan on putting the KN intake system and the suspension up grades on. If there any advice to be given I'd appreciate it. Am I missing anything. I would imagine will have this car for life. Thanks Rob Proffitt
 
Our '05 was running rough so I replaced all the plugs and coils at 41k and it runs perfect again. Every plug and coil I removed was checked for gap and cleanliness. I also ohmed each coil I removed and they all looked good. I never found out which one or ones were going bad but the car runs perfect again. Good luck. Let us know.
Thank you. I'm starting that project in a couple weeks and I'll make sure that I add that to my list to do.
 
Just joined and need some advise please. I purchased a 2003 t-bird for my wife,new in 03. She loves the car, but we've had tons of trouble out of it. According to the Ford mechanics it's the computer. We've put 3 computers in it and finally they put a Lincoln one in and it's worked the best, but still doesn't work right. Engine runs very rough. It runs so rough it shuts off. Ford sent me a new computer, which I still have in the box. That's the history. Car has 36000 miles on it and other then the computer chages it's all stock. I've read the upgrades reccomend and were going to do them all. A couple questions. do I need a new computer use the one Ford sent me or leave the Lincoln one in it? On the Bola exhaust would it be better to put new headers on when we put the cat backs on? Also plan on putting the KN intake system and the suspension up grades on. If there any advice to be given I'd appreciate it. Am I missing anything. I would imagine will have this car for life. Thanks Rob Proffitt
 
Thank you. I'm starting that project in a couple weeks and I'll make sure that I add that to my list to do.
Since the Coil problem is by far the most common problem for these cars and you never mentioned it and your dealer replaced several computers you may want to find another dealer. While you may get varying opinions in this forum you will get honesty.
 
You are correct. I fired them several years ago. When they put the ls computer in it help. Now it still does it every now and then. I have to make sure this is taken care before I start the mods to wake up this little motor. It stays in the garage most of the time. Only drive it occasionally, we are going to change that.
 
Have you recently put a OBD reader on to see what trouble codes the car has. It would be very helpful to know these codes. The car may have other stuff acting up other than coils. The codes can lead in the right direction instead of "shot gun" troubleshoot ing. If you don't have a OBDII reader you need to get one.
 
Thank you. I have but I don't remember the code. It is driven so very little mainly by my wife I'm not around most the time She's drivinr intake.......g it. I'm having a performance shop do ing the upgrades,Bola exhaust, supercharger, air intake...... So I appreciate you let me know there were other issues to. Do you know much about the Bola exhaust? With the Bola system, do you need aftermarket headers or will OEM work?
 
Rob, sorry to hear about the issue, but when you say or Ford day computer where to you really mean? Do you mean FEM, REM or what did they specifically say.

As for the last four years I have had my bird I have not seen us having issues with computers. As stated from others having the correct code reader leads you in the correct path to fixing. I trust myself and my non dealer mechanic to give us the right remedies. Please don't spin your wheels and spend a fortune on repairs some one is guessing at.
 
Thank you. I'm starting that project in a couple weeks and I'll make sure that I add that to my list to do.
you should make the plug and coil over plug change first-- not put it on a list--I still consider myself a rookie at all being here less than two years but from reading here the C.O.P is a super common problem that gives the issues you have described and also the most common fix. your FEM(computer) wont help if the c.o.p. are bad.
 
Thank you all so much. The FEM/computer problems we had were during the first years we owned the car. The dealership, under warranty at the time, were the ones that said the FEM was the problem. We have taken care of the issue ( with the Exception of every now and then when it's cold it will miss until it warms up), but I think the new coils will help that. I wanted to make sure that FEM didn't need to be replaced before I start the performance up grades ( In other words there wasn't a perpetual problem with the FEM). My wife loves this car, I'm gonna keep it for ever I guess ( Can't say it's my favorite car unless the tops down or I can cut a hole in a convertible put my head through, I would take my 1988 Mercury Mukar any day). Since we're now in the sunshine state you can dry it with the top down. I'm trying to get a handle on what performance upgrades or known problems are with this car so we can enjoy it a little bit more. What I heard so far is there's a known problem with the coils, a bola exhaust system( using the stock headers), tuner, air intake,Will make a world of difference in this little v8. Is there anything I'm missing? Thanks again for all the input. Any advice would be much appreciated. Thank you again for all the comments and suggestions.
 

cdbintexas

Well-Known Member
Just joined and need some advise please. I purchased a 2003 t-bird for my wife,new in 03. She loves the car, but we've had tons of trouble out of it. According to the Ford mechanics it's the computer. We've put 3 computers in it and finally they put a Lincoln one in and it's worked the best, but still doesn't work right. Engine runs very rough. It runs so rough it shuts off. Ford sent me a new computer, which I still have in the box. That's the history. Car has 36000 miles on it and other then the computer chages it's all stock. I've read the upgrades reccomend and were going to do them all. A couple questions. do I need a new computer use the one Ford sent me or leave the Lincoln one in it? On the Bola exhaust would it be better to put new headers on when we put the cat backs on? Also plan on putting the KN intake system and the suspension up grades on. If there any advice to be given I'd appreciate it. Am I missing anything. I would imagine will have this car for life. Thanks Rob Proffitt
You will get as many suggestions as there are belly buttons but here is my 2 cents worth. 1) change only one thing at a time and drive a week between changes. 2) First cure for rough running engine is new plugs and Coils on Plugs (Cops). Remember everything on this car is first generation microprocessor controlled and interconnected. I really think in my own case a new battery "fixed" a slow shifting servo in the the transmission saving me 2-3 K $. Only time will tell. cdbintexas
 
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