I just bought this f250-5.0efi. The last owner gave up after changing all the sensors ,fuel regulator,plugs,wires,cap rotor, everything except the computer. I can hear the fuel pump. the air cleaner is off and if you crank it with you hands over the intakes it will fire and die while trying to suck your fingers into the pipes. Any ideas? junk yard said save the $100 for the computer and check the grounds. which ones where? standing by

 

i'd start by pulling the codes. check the fuel pump make sure it has the right amount of pressure. my high pressure pump went out awhile ago.fuel delivery was low. when i turned the key you could hear the pump run but the engine would not start. just a thought, good luck.

 

thanks...the last guy said the codes told him the engine was hot,but it wasn't running.I put in a fresh battery so I guess that reset everything and I will try to pull the codes. boy is this different than all my VW's. got the Haynes book today and am starting my education. any suggestions on what kind or brand of fuel pressure checker? also he said there was some kind of button by the fuel regulator that he pressed and it almost blinded him when the fuel came out... it's about 95 here in the keys so I'll check back when I come in to cool off in the ac. JJ

 

When you are new to computer controlled vehicles there is a lot of new stuff to learn and it is intimidating. Read the books and learn to test components without destroying anything. All of the basics still apply. If you have compression, fuel and spark, it will run.
Learn to run searches here also, it will be worth your time.

 

just tried to pull the codes, not much luck. the fuel pump didn't seem to quit, the light barely blinked but the in dash volt meter pulses as if it were a flash, no headlights but the fuse is intact ...sound familiar to anyone...

 

I had a similar condition on my 95 150... good spark, pressure at the fuel filter, new pump, good compression, etc... just cranked and cranked after shutting off, but was getting good spark. After pulling my hair out and testing everything in the world I could think of, I tried bypassing the automatic fuel cutoff switch and viola!!!!!! Replaced the switch and haven't had a problem since.

Girlfriend had exactly the same thing happen... after ensuring spark and fuel and compression were good, I naturally went right to that switch and, nothing. GRRRRRR. Finally, I did change the ECM, though it wasn't throwing codes, and poof!!!! Truck fired right up and haven't had a problem since (sans that wiring harness on the alt catching fire.

So, there are two scenarios with exactly the same problem with no CEL codes that were fixed. If you'd like, you can short/test the switch and the ECM (that's what I suggest), but my test showed my switch good when it wasn't.

Hope this helps, and keep us appraised of what it was, please.

 

Richard, I have the same problem. I've replaced the ecm, and I have good spark and it seems like I have too much fuel. I'm going to test the pressure of the regulator today, but your post about the cutoff switch is interesting, could you walk me through on how to bypass the switch. Are you referring to the inertia switch, which is on the firewall behind the pedals???

 

ok, I got some new information. I'm suspecting that my fuel pressure regulator is bad, I pulled the vacumn line off and there's gas in the line, so undoubtably, I have a bad regulator. I'm fairly sure that this is what is causing my no-start conditional. My question is does anybody know how to replace this???

 

Well, I don't know what you mean by too much fuel... what are the gauges showing, and what year are you running? Try to be more specific, because around 93, 94, 95, 96 Ford was making some pretty serious changes to both their fuel delivery and electronic systems. The intertia switch is different from the cutoff switch, though... the easiest way to tell (if you have made no modifications to the hood) is a sticker that can be found next to the belt routing sticker (normally 93 and above on the full body): sometimes it is on the hood, sometimes on the front rail where the radiator mounts... it will say that the vehicle is equipped with a shutoff switch (only on the non-ambulatory packages).

If you have a fuel cutoff switch (which are pretty standard) it is probably mounted on the passenger side in the cab, about 1/2 way from the tranny hub to the door, and looks like any mercury-activated switch. Ford messed with this, so without knowing exactly what you are driving I can't be more specific.

To bypass the switch, take a lead and find the KOER (key on, engine running) source, AFTER you try to reset it (looks like a thermal switch push in button), and then find the output wire. Tie the two together AFTER removing the fuse with the ignition off. Put the fuse back in and see if it starts.

On your truck - once again, I have no idea what you are driving at this point - the inertia switch could be the same as the cutoff, or it could be different. It could also be in a different place... let me know if you need more specific details, and I will help you to the best of my ability.

 

LOL... apparently we were both disgusted with NASCAR today, 'cause we are posting at the same time, LOL. Tell me what you are driving and I will do what I can... check back in 15

 

i'm driving an 88 F250 5.8L. I found the cut-off switch, it is behind the pedals on the firewall, but I checked it and it is in the right position, it has not been activated. After finding all the fuel in the vacumn line, I'm inclined to think that the bad fuel pressure regulator is causing my problems. I need some info on how to replace it. I really don't feel like removing my upper manifold to get to the fuel rail. Any help would be appreciated. Thanks

 

tried to do the codes again with a small 12v bulb...when i grounded the single wire for the codes the bulb came on dim, then when I turned the key on it got bright but no blinks...I have the dash check engine light but it doesn't blink either. the fuel pump doesn't shut off as it's supposed to so next step will be to get a fuel gauge. does the fuel pump running stop the codes? would that be a bad relay. the fuel gauge shows full with key off and 1/4 when the keys on,is that normal? 1990-302 tried spraying ether and starting and it fired and died. any good qlues here? the fuel regulator is new...

 

well I just did the fuel pressure check 40 lbs. but the leak down check failed...drops to 20 real fast and then VERY slowly drops to nothing. tried to pinch the return line with vise grips but that didn't work. fuel pump doesn't shut off, could the tank be empty? tank gauge says 1/4 full -regulator looks new

 

Hope you got it fixed by now but if not I'll bet it may be the timing. My truck would just turn over and over and I put over $200.00 into egr, TFI, Fuel pressure regulator, fuel relay, cap, rotor, ignition coil, plugs and wires. Then my wife got mad at seeing it sit in the driveway and had it towed. Ended up being that the timing chain slipped a few teeth and was so far out it wouldn't start. They put in a new timing set and truck started right up and runs perfectly. Said the problem is pretty common on 5.0 with the nylon gear in the timing. Since our trucks are the same year you might want to check it out. Hope this helps.

 

I am with First Time 4X4 too, I just did a GM 3.8 that did the same thing, Turn the crank until the #1 hole is TDC and pull the distributor and make sure it is pointed twords the #1 wire. IF it is the timing gear, Pull the oil pan off and clean out all the plastic shavings. Otherwise a week later your motor will be shot because it pluged up the oil screen.