87 F150 Running Rich

I have a 87 f150 that is running rich and getting horrible gas milage. I was wondering what suggestion people have. I know i have cracks in my exaust manifolds, could that be hurting me at all?

If your manifolds are leaking you could burn a valve, but I doubt it. If its running rich it could be several things, too much fuel pressure, dirty air filter, ect. I know my 1990 f150 was running rich bad when the filter got real dirty.

Well, i assum this is fuel injected. First off, new fuel filter and air filter. Then i would reaplce all the oxygen sensors, they usually only last 80K before starting to go bad. Now if your truck is carbureted, i would put a carb kit with a new power valve and air and fuel filter. Fuel filter can make a big difference in efi due to spray patterns and fuel pressure.

hey thanks for the ideas I will give them a try