460 start problem
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New User
Joined: Jan 2003
Posts: 21
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From: Washington
460 start problem
I have this problem with my 88 F250, 360 FI. It has run fine for months. Then one day it would not start, just crank. Spark checked good. Fuel was pressurized (squirted out the valve on the fuel rail). If I press the gas pedal to the floor it will start(read in the manual later that this works when the engine is flooded), rev up and die. Did this several times. Then on the next try it started normally. Has done this several times now (in the driveway).
I replaced the fuel pressure regulator, pulled the injectors and had them serviced(they were pretty dirty, but not leaking or stuck). Replaced plugs and wires. The only code is 11. Still having the same problem.
Any suggestions greatly appreciated.
Thanks
I replaced the fuel pressure regulator, pulled the injectors and had them serviced(they were pretty dirty, but not leaking or stuck). Replaced plugs and wires. The only code is 11. Still having the same problem.
Any suggestions greatly appreciated.
Thanks
Thread Starter
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New User
Joined: Jan 2003
Posts: 21
Likes: 0
From: Washington
460 start problem
Thanks for your input guys. Still no go.
Since last reply I have checked all vacuum lines and they are ok. I have replaced the MAP sensor and that did not help. I checked the fule pressure on the rail connection and get 40 lb with power on and that drops to 34-36 when cranking and to 32 when it starts. Consistently, so I think I can rule out fuel starvation. Spark is good. The only thing left that I can think of is the pulses to the igniters. I smell fuel when I press pedal to floor to start so think it is flooding, then when it starts it idles but if I try to rev up it dies. If the pulses are too long keeping the injectors open longer than they need to be and run very rich. What would cause that. I don't have a scope so can't verify this.
Any other suggestions appreciated.
I am committed to this now.
Can't take it to a mechanic at this point.
Well, back to the books.
Since last reply I have checked all vacuum lines and they are ok. I have replaced the MAP sensor and that did not help. I checked the fule pressure on the rail connection and get 40 lb with power on and that drops to 34-36 when cranking and to 32 when it starts. Consistently, so I think I can rule out fuel starvation. Spark is good. The only thing left that I can think of is the pulses to the igniters. I smell fuel when I press pedal to floor to start so think it is flooding, then when it starts it idles but if I try to rev up it dies. If the pulses are too long keeping the injectors open longer than they need to be and run very rich. What would cause that. I don't have a scope so can't verify this.
Any other suggestions appreciated.
I am committed to this now.
Can't take it to a mechanic at this point.
Well, back to the books.
Senior User
Joined: Jun 2002
Posts: 263
Likes: 1
From: British Columbia
460 start problem
Well, if the spark is for sure good, and fuel pressure is good, there must be a fuel control problem. For some reason it sounds like the injectors are not being fired properly. From where I am I can't help you as your problem is complex in nature. You basically need to do a total code scan KOEO and KOER. If these don't yeild any results you need to do a pin voltage test off of the PCM. Sorry I can't make it simple but unless you want to make more stabs in the dark at replacing parts this is the only way to properly diagnose this thing.
Good Luck
Good Luck
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