Pulling my hair out
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Junior Member
Joined: Jan 2011
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okay. sorry for taking so long to respond. been really busy fixing other p.o.s. i own. so i've replaced the IAC, crank sensor, ECT, and the MAF. Replaced the MAF because the PCM finally gave 2 codes one said too lean and the other said too rich. Found no air leaks so the only conclusion I had was to replace the MAF. Cleared the codes and no others have come up.
Seems like every time i replace a part the thing starts and runs fine then the next day it won't start again. just turns over.
Today I sprayed starting fluid down it's throat and got nothing. Fuel pump seems to be working as it showed 40psi on the rail again when i checked. Also disconnected the remote starter/alarm system and it still just turned over.
I feel like doing what those guys in office space did to that computer.
Oh as for any aftermarket stuff. cold air intake, bigger throttle body. cat back dual exhaust and the edge programmer. the programmer has been on the same settings for the past 2+ years. also put the truck back to factory settings but no luck getting it started
Seems like every time i replace a part the thing starts and runs fine then the next day it won't start again. just turns over.
Today I sprayed starting fluid down it's throat and got nothing. Fuel pump seems to be working as it showed 40psi on the rail again when i checked. Also disconnected the remote starter/alarm system and it still just turned over.
I feel like doing what those guys in office space did to that computer.
Oh as for any aftermarket stuff. cold air intake, bigger throttle body. cat back dual exhaust and the edge programmer. the programmer has been on the same settings for the past 2+ years. also put the truck back to factory settings but no luck getting it started
Thread Starter
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Junior Member
Joined: Jan 2011
Posts: 7
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I don't have the codes anymore after clearing them they never came back. think the o2 was giving the reading from the extra fuel being dumped while trying to start the truck. think i'm going to bite the bullet and let the dealer deal with it or maybe have it crushed just to get some satisfaction 
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Joined: May 2011
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95K miles on my F250 4.6L, I had a crank but no start problem that was very intermittent, some days it would start and run fine for a couple of days before reverting back to a no start condition.
Below the driver’s side dash, there is a diagnostic plug for connecting and OBII Meter tool. I plugged my OBII Meter into the diagnostic plug, turned the key on, pressed the Linked button on my OBII meter, and received a zero code.
On the passenger side of truck, in cabin, just above the lower kick panel, if you reach your fingers in there you will find a module called an inertia switch, atop of this switch is a reset button, push it down. If you are able to push it down, try and restart your engine. Mine was already in the down position.
I pulled out a spark plug wire and using a spark tester tool, I found that I was getting spark. I unscrewed the valve cap off the passenger side fuel rail, and depressed the Schrader valve to see if I have fuel pressure or fuel coming out of it. I did not have any pressure, or fuel present after depressing the valve. While still depressing this valve, I had my wife crank the engine over, so I could see if there was any indication of fuel pressure or fuel was going to come out of that Schrader valve, still nothing. At this point I was pretty sure I had a fuel pump problem.
I replaced the fuel filter, and then the engine started, it ran good the rest of the day, but the very next morning, it would crank over but not start.
My next step, I replaced the 3 relays on the driver’s side engine compartment, the Horn relay, the Fuel Pump Relay, and the PCM relay. Car still would not start.
I pulled the boot off the throttle body, sprayed some starting fluid in there, put the boot back on, and tried to start the engine, the engine started right up, and ran fine the rest of that day. The next day the engine wouldn’t start again.
I then had my wife stand next to the gas tank. I fastened my seat belt, closed my door, turned the ignition key to the “On” position, and listen for a fuel pump noise. My wife and I heard nothing. So we tried this again, but this time I took off the gas cap, and had my wife listen again, why I turned the key on, still no sound of noise. I was pretty convinced that it must be the fuel pump.
Trying to rule out a few more items, I decided I was going to replace the crank sensor. The crank sensor had never been changed. The crank sensor does the same thing basically that the pickup coil did in the distributors of older vehicles. In older vehicles I usually replaced the pickup coil every 60K, but never gave a thought of replacing the crank sensor as part of the maintenance routine. So I installed a new crank sensor. As I wrote that into my maintenance notebook, I noticed that I hadn’t changed the spark plugs in 36k miles (7 years). Wow has it been that long, I thought. So I installed a new set of spark plugs as well. I went to start the engine, and without any effort, without even seeming to crank over, the engine started so quickly I was amazed. It’s been a week now without one incident of a no-start condition.
Early on I would have ruled out the crank sensor and the spark plugs because I had spark, when I tested the spark at one plug wire. When the engine did run, it ran fine. But the fact that after changing the spark plugs and the crank sensor, the engine doesn’t seem to even crank anymore, it just effortlessly starts instantly, which I don’t really recall it starting so quickly in years, makes me believe it was a combination of the two. I have learned that the PCM shuts down the signal to either the fuel pump or the injectors after cranking for several seconds.
Looking at the schedule maintenance book in repair manual, it states to replace spark plugs every 100K miles. My 36K platinum premium plugs, were shot. I would recommend that the plugs be changed ever 30k miles. I would also recommend that the crank sensor be replaced every 60k at the same time when the serpentine belt is replaced. Other than that follow the maintenance schedule for other items as noted.
Below the driver’s side dash, there is a diagnostic plug for connecting and OBII Meter tool. I plugged my OBII Meter into the diagnostic plug, turned the key on, pressed the Linked button on my OBII meter, and received a zero code.
On the passenger side of truck, in cabin, just above the lower kick panel, if you reach your fingers in there you will find a module called an inertia switch, atop of this switch is a reset button, push it down. If you are able to push it down, try and restart your engine. Mine was already in the down position.
I pulled out a spark plug wire and using a spark tester tool, I found that I was getting spark. I unscrewed the valve cap off the passenger side fuel rail, and depressed the Schrader valve to see if I have fuel pressure or fuel coming out of it. I did not have any pressure, or fuel present after depressing the valve. While still depressing this valve, I had my wife crank the engine over, so I could see if there was any indication of fuel pressure or fuel was going to come out of that Schrader valve, still nothing. At this point I was pretty sure I had a fuel pump problem.
I replaced the fuel filter, and then the engine started, it ran good the rest of the day, but the very next morning, it would crank over but not start.
My next step, I replaced the 3 relays on the driver’s side engine compartment, the Horn relay, the Fuel Pump Relay, and the PCM relay. Car still would not start.
I pulled the boot off the throttle body, sprayed some starting fluid in there, put the boot back on, and tried to start the engine, the engine started right up, and ran fine the rest of that day. The next day the engine wouldn’t start again.
I then had my wife stand next to the gas tank. I fastened my seat belt, closed my door, turned the ignition key to the “On” position, and listen for a fuel pump noise. My wife and I heard nothing. So we tried this again, but this time I took off the gas cap, and had my wife listen again, why I turned the key on, still no sound of noise. I was pretty convinced that it must be the fuel pump.
Trying to rule out a few more items, I decided I was going to replace the crank sensor. The crank sensor had never been changed. The crank sensor does the same thing basically that the pickup coil did in the distributors of older vehicles. In older vehicles I usually replaced the pickup coil every 60K, but never gave a thought of replacing the crank sensor as part of the maintenance routine. So I installed a new crank sensor. As I wrote that into my maintenance notebook, I noticed that I hadn’t changed the spark plugs in 36k miles (7 years). Wow has it been that long, I thought. So I installed a new set of spark plugs as well. I went to start the engine, and without any effort, without even seeming to crank over, the engine started so quickly I was amazed. It’s been a week now without one incident of a no-start condition.
Early on I would have ruled out the crank sensor and the spark plugs because I had spark, when I tested the spark at one plug wire. When the engine did run, it ran fine. But the fact that after changing the spark plugs and the crank sensor, the engine doesn’t seem to even crank anymore, it just effortlessly starts instantly, which I don’t really recall it starting so quickly in years, makes me believe it was a combination of the two. I have learned that the PCM shuts down the signal to either the fuel pump or the injectors after cranking for several seconds.
Looking at the schedule maintenance book in repair manual, it states to replace spark plugs every 100K miles. My 36K platinum premium plugs, were shot. I would recommend that the plugs be changed ever 30k miles. I would also recommend that the crank sensor be replaced every 60k at the same time when the serpentine belt is replaced. Other than that follow the maintenance schedule for other items as noted.