89 F-250 won't idle

[new_age_devil]

I posted this in the tech forum but haven't gotten a response and now it runs worse , anyway, i have an 89 f-250 7.5L MPI. lately its been running very rich, and when ya drive it down the highway it cuts out an backfires, now it won't even idle in park, but it will idle in drive, i just changed the o2 sensor, plugs wires cap and fuel filter. I was told it could be the fuel pressure regulator and that i could check it by taking the vaccum line off of it and to turn the key, if fuel comes out of it does that mean that its bad? Any help and ideas are greatly appreciated, thanks

 

[adysvn]

I posted this in the tech forum but haven't gotten a response and now it runs worse , anyway, i have an 89 f-250 7.5L MPI. lately its been running very rich, and when ya drive it down the highway it cuts out an backfires, now it won't even idle in park, but it will idle in drive, i just changed the o2 sensor, plugs wires cap and fuel filter. I was told it could be the fuel pressure regulator and that i could check it by taking the vaccum line off of it and to turn the key, if fuel comes out of it does that mean that its bad? Any help and ideas are greatly appreciated, thanks

[snapback]16400[/snapback]​

i had the same problem once and found out ford has two fuel pumps one on the rail and one in the gas tank the one in the gas tank was at fault and caused the symptems u described