460 running rich
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460 running rich
I just replaced the 460 in my 1989 F250 4X4 and it's running extremely rich. I'm pretty sure that I have everthing hooked up correctly and I used all of my original sensors. Truck ran fine before the change, it just used a lot of oil. Now when I get it started it pours out black smoke and runs very rough. I don't have a fuel pressure tester, but I put on a new kirban fuel regulator that I have for my 5.0 mustang. No change. When I unhook the fuel relay, it immediately runs great for about 10-15 seconds until it runs out of fuel. It has about 17 inches of vacuum at the regulator. Timing is set at 10 degrees BTDC. Haven't checked for trouble codes. Not sure if I remember how. This is probably something simple, but I don't have much experience with fuel injection
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From: Sealy TX
It sounds like your oxygen sensor on your exhaust might be unplugged or bad. On that regulator though, you might want to check your fuel pressure, I know the 5.0 has orange topped injectors and the 460 has green ones, I dont know if the pressures are the same for them, the 460 might reqiure more or less i dont know the specs
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I checked the O2 sensor to make sure it is was plugged in. It is located in the exhaust pipe by the trans. I didn't have to unplug it to change engines. I guess it could have gone bad but i don't know how to check it. I hate to start guessing and replace parts that I don't know that are bad. I put the kirban fuel reg on just to check if I had way too much fuel pressure. I am going to take it off and save it for my 5.0 BTW stock injectors for mustangs are 19lb. and are orange and stock injectors for my 460 are 24lb. and are blue. I think that fuel pressure for both should be about 35-45 psi.
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I replaced the O2 sensor and it didn't make any difference. still is pouring black smoke out of the tailpipes. I know the fuel reg. is good. there is no fuel in the vacuum line that would indicate a ruptured diaphragm. Still have on my new fuel press. reg.
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I finally got this fixed. Called a friend of mine and he told me exactly where to look. I somehow knocked the plastic vacuum line off to the map sensor. hooked it back up and now it's running much better
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Happened to me not 2 months ago on my 85 F250. Exhaust leak on the back of heads crossover pipe melted the vacuum line to the map sensor, ran **** poor and black smoke. Spent $200.00 to diagnose a .50 cent piece of hose... Happy motoring.
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