My 1989 Formula Convertible is sick. The car has a 305 TPI, a 5-speed and dual cats. It starts fine, but usually idles a bit rough. It also feels a weak, has a stumble at steady throttle and spits black soot out of its tailpipe. The car is essentially stock and has 62,000 miles on it. It obviously sits more than I drive it. Have my injectors gotten old? Any help would be greatly appreciated.

 

I have the same problem with new injectors, its not always the case but is alot of the time.

 

The soot coming out of your tailpipe is probly just carbon in the exhaust and it's getting carried out by the moisture in the pipes, take the car out, and really drive the thing, run it hard, put some good high octane gas in and drive it. You could probly change your air filter and put in a good o2 sensor, and hell do a full tune up, But mainly just go drive it.

 

Sounds like yer running rich. Mine did everything you stated until I leaned out the programming.

 

my car is doing exactly the same thing and im getting sick of it...im also getting a rich code from my o2 sensor. when you rev your car to about 2000 in park does it feel like you will vibrate out of your seat? haha

i need to check the injectors im pretty sure...ohm them out

 

Vibrating that bad? You may want to make sure everything's firing. You might have a dead miss.

 

Run some Sea-foam through it.
And beat the crap out of it for a 1/2 a tank of gas.
I remember carbed cars....I used to pour water down the carb and rev it up to keep the car running. It was the easiest way to clean carbon build up.

 

well looks like i may have found the problem
6 out of 8 injectors are bad...ranging anywhere from 2 at 16.7, 2 at 14 ohms, 2 at 10 ohms, and 2 at 7 ohms...16.7 is what they are supposed to be around

a buddy of mine has a set of 19lb for injectors off his mustang that is is going to give me for free...they ran fine on the car he had but i will ohm them out first

 

post some pics!! Thats a very rare car!

What colour??