I have an 85 grand marquis with a 5.0. I keep getting the code saying it is running lean all the time. any ideas? the only thing that has been done is the smog pump and ac have been removed recently.

 

If the smog pump has been removed, you'll have to re-tune the car if it's carbureted (can't remember if the 85 was injected or not). For injected engines, they should compensate. You may also have a fuel pump issue that isn't keeping up with the needs of the engine. Check the fuel pressure and replace the fuel filter if that hasn't been done for a while. Carbureted engines should generally run fuel pressure below 10psi but usually at least 4-6 psi. If you have a mechanical fuel pump and it has weakened, it may be leaking gas into the oil. This can be a very bad thing. You may need to replace the fuel pump and change the oil.

 

How's the car run otherwise?? Vac leaks and exhaust leaks (pre oxygen sensor) can set that code... AS well as a bum oxygen sensor..

 

car runs ok unless you try to braketorque it then it dies. as far as i can tell by the carb cleaner test i have no vac leaks. the car is injected with a feul pressure of 39 psi. o2 sensor replaced recently possible exhaust leak. feul pump hasn't been changed as far as i know but filter was changed just 150 miles ago. will use seafoam test to check for exhaust leaks tomorrow. any other ideas?

 

ran seafoam and only leak in exhaust is in the flange between the manifold and the cat converters.

 

have you run some injector cleaner through it recently? you have good fuel pressure, good (hopefully) oxygen sensors, and nothing else sounds like it's having issues... the injectors might be clogged up some. If you've been running discount gas through it, then that's probably the issue. run a couple tanks with some good injector cleaner (or fuel system cleaner) and that might sort it out. it could also be carbon build up in the engine. This is especially common on cars that never see the highway. Though this is usually more a rich condition.

Mainly, if it's not the injectors (and they may be worn out too), I'm really out of ideas.

 

i think the injector cleaner should help it....