I just got a 1996 Ford Thunderbird from an older couple who kept the car at their Vacation home in Florida and was only driven 3 months out of the year. They had it there for about 8 years, and before that it belonged to an old man who bought it new and used it to put around town at 20 mph. It is just about to roll over to 60k miles. I just replaced the intake manifold, fuel filter, PCV valve, front brake pads and rotors, spark plugs and wires. The car runs extremely well at idle, but when you put your foot down, it seems very doggy at first and only tends to pick up speed in 2nd gear. The likelihood of anything being replaced besides what I just replaced is very slim. The 0-60 time is supposed to be around 8 seconds, and we're getting 18-20 seconds each time. Please help, besides being slow, the car is perfect!

 

Before getting involved in a lot of unnecessary work, why not try a tankful or two of premium gasoline and see that makes any difference. If you have already done that maybe it just needs a good run on the pike at the speed limit of course ! This is not an unusual problem with vehicles that rarly go over 25 MPH..

 

I would start with checking fuel pressure. With so much down time and possible fuel going stale, the fuel pump may be marginal. You never mentioned which engine you have an idle pressure of 28-54 psi for the 3.8SC and 30-45 psi for the 4.6.I assume you have the V8 since you had to change the intake manifold.I would also check and make sure pressure holds after shutdown and when you work it. Won't hurt to check for any stored coded as well.

 

It seems to be getting better after about 2 tanks, down to about 14-13 seconds. I'll keep driving and let you know!

 

I just checked fuel pressure from the fuel rail on the driver side and got 35 psi from idle and 40 when revving up. And yes, it has a 4.6 V8. So what you're saying is that when I shut down the car it should hold fuel pressure at the rail?

 

Yes, I should hold pressure for a long time. If it doesn't, some things to look at are an injector(s), fuel pump issues with its check valve or a leak somewhere.

 

Thank you to all who helped, but I accidentally found the problem when cleaning the engine bay. I disconnected the air intake hose and set it down and I must have gotten the MAF sensor wet. When I put everything back together, the car would bog down when I tried to rev it up. After some troubleshooting I figured out the MAF sensor was the problem all along and I just made it worse by getting it wet. The car now runs like new and has plenty of power after buying a new one.. It is still throwing a code and i haven't scanned it yet to see, but I'll bet its only the EVAP code and no longer the running lean codes. Thanks!