Pirate 4x4 banner

1 - 20 of 22 Posts

·
Registered
Joined
·
2,970 Posts
Discussion Starter #1
" 96 F350 4x4 power stroke diesel."
I am not new to pirate, I am usually over in Landcruiser section but thought it might be worth a shot here in Gen 4x4 for my problem.
I asked this question over a year ago with minimal replies , we are frustrated and need the help of the board.
The problem is simple and intermittent, at various times when he turns the key off, the engine continues to run. Sometimes after a few minutes it will shut down. Sometime it could run for hours unless I pull the fuse to shut it down. AFAIK there is no emergency fuel cutoff under the dash/panel on a 96?.. am I correct? That's why we pull the fuse.
The engine starts fine, runs well but the shutoff system is not functional part of the time. This truck has been to 3 Ford dealerships here in Utah and the ingnition, and mechanical (plastic) parts in the column related to the shutoff have been replaced. The problem returns after service or will not show up (naturally) when taken to the dealer. I hate to throw good money toward more dealerships guessing at the problem. I was wondering if someone could explain to me the method of operation of the shutoff once the key is turned to the off posistion. Is it solenoid actived or mechanically activated when turned off? I am assuming there is a fuel flow cutoff solenoid in the open position that closes ( default)? ..when the key is turned off? Please feel free to chime in on anything you might suspect. I am open to all suggestions..take a shot at it.


Bennett
 

·
Banned
Joined
·
5,372 Posts
Do all of the other "key on" items operate (i.e. radio, heater) , or is it only the engine that keeps running?

If its the engine only, just install a switch to the fuel pump. Makes a good anti-theft deterrent at the same time.
 

·
Registered
Joined
·
12,645 Posts
deisel's stop running only when you cut off fuel. no spark. heat compression, and deisel fuel cuases the combustion. You have a fuel cut off problem. If a powerstroke has a rubber fuel line like my 7.3 non power stroke get out and crimp the line with a pair of vice grips.
 

·
Registered
Joined
·
2,970 Posts
Discussion Starter #4
Pavemen said:
Do all of the other "key on" items operate (i.e. radio, heater) , or is it only the engine that keeps running?

Yep... everything elese works fine... just won't shut down.
I have thought about a switch but would like to find problem and solve it without another switch... but thanks

Noodle.. I can shut it down several ways, including crimping the fuel source. Pulling that #3 fuse is easy and takes just a minute once the hood is up. It is annoying. Part of the other problem is this is my dads trcuk and he is 76... he can't even remember where the fuse box is under the hood each time.. I labeled it and painted the fuse bright red.. still forgets and always calls me ..
the dealers are screwin him over though , I gotta figure this out.
 

·
thhhpptthh!
Joined
·
46,718 Posts
noodles said:
deisel's stop running only when you cut off fuel. no spark. heat compression, and deisel fuel cuases the combustion. You have a fuel cut off problem. If a powerstroke has a rubber fuel line like my 7.3 non power stroke get out and crimp the line with a pair of vice grips.

i know very little about desiels but i know our semi has the exact same random problem. Its the fuel cutoff switch. On the semi the switch has a manual overide knob on it, we just open the hood and screw it down. maybee that'll help you :confused:
 

·
Registered
Joined
·
348 Posts
bennett said:
" 96 F350 4x4 power stroke diesel."
I am not new to pirate, I am usually over in Landcruiser section but thought it might be worth a shot here in Gen 4x4 for my problem.
I asked this question over a year ago with minimal replies , we are frustrated and need the help of the board.
The problem is simple and intermittent, at various times when he turns the key off, the engine continues to run. Sometimes after a few minutes it will shut down. Sometime it could run for hours unless I pull the fuse to shut it down. AFAIK there is no emergency fuel cutoff under the dash/panel on a 96?.. am I correct? That's why we pull the fuse.
The engine starts fine, runs well but the shutoff system is not functional part of the time. This truck has been to 3 Ford dealerships here in Utah and the ingnition, and mechanical (plastic) parts in the column related to the shutoff have been replaced. The problem returns after service or will not show up (naturally) when taken to the dealer. I hate to throw good money toward more dealerships guessing at the problem. I was wondering if someone could explain to me the method of operation of the shutoff once the key is turned to the off posistion. Is it solenoid actived or mechanically activated when turned off? I am assuming there is a fuel flow cutoff solenoid in the open position that closes ( default)? ..when the key is turned off? Please feel free to chime in on anything you might suspect. I am open to all suggestions..take a shot at it.


Bennett

The PSD does not have a "fuel cutoff" because the fuel pump is mechanical up to the newer Superduty's in 1999 or so which switched to electric. Which fuse are you pulling? The PSD is completely computer controlled. The injectors are fired electrically by the IDM on commmand from the ECM. I'd get the wiring diagrams and see if the ECM is still receiving power with the key "off". Do the gages still function when this happens? How about a ground problem?
 

·
Registered
Joined
·
4,797 Posts
Do you have test light and a manual? What I would do is trace down the circuit through all the harnesses and at each point where the power is switched. Trace the circuit during the start, run, shutdown and off cycles. Make a list of test points, I.E. before after relays, fuses, at the pump etc.

Once you have the check list the next time it won't shutoff begin going through the check list until you find the an item that is not turned off and begin tracing that circuit.

Things I would look for; any relays or switches that control the circuit, any switched power sources and what controls it, the computer if it controls the shutdown of the fuel pump.

Sorry I'm totally diesel dumb but hope this info helps from an electric.
 

·
Registered
Joined
·
1,170 Posts
Re: Re: Can't shut off my diesel 4x4?

hightechredneck said:



The PSD does not have a "fuel cutoff" because the fuel pump is mechanical up to the newer Superduty's in 1999 or so which switched to electric. ?
those used a db2 bump if i remember corectly. if you look at the top of the motor, in the frunt you will see the injection distributer. on the top of it is a rectangular housing w/ 4 bolts and a single wire (pink if i remember) . when the wire is energised it will allow fuel to pass into the injection pump/distributer. so, it is posable to cut the wire, rout it to a switch on the dash , then back to the pump so you can cut the power manualy. he would just have to remember to turn it back on to start the truck.

hope that helps
 

·
Registered
Joined
·
348 Posts
Re: Re: Re: Can't shut off my diesel 4x4?

T1H5_TA3 said:


those used a db2 bump if i remember corectly. if you look at the top of the motor, in the frunt you will see the injection distributer. on the top of it is a rectangular housing w/ 4 bolts and a single wire (pink if i remember) . when the wire is energised it will allow fuel to pass into the injection pump/distributer. so, it is posable to cut the wire, rout it to a switch on the dash , then back to the pump so you can cut the power manualy. he would just have to remember to turn it back on to start the truck.

hope that helps
The PSD does not have an "injection distributer". The PSD is not the old 7.3 IDI motor with a mechanical injection pump. It has a mechanical "tandem pump" which pulls fuel from the tank and delivers it to the fuel filter at about 4psi. The high pressure side of the pump then delivers fuel to each cylinder head at 50-70psi. There is a ECM (PCM) relay which might be sticking. With the PSD, if you are adding wires to the engine to get it to shut off, something is WRONG!

NOTE: I didn't list every part of the fuel system such as the pressure regulator, etc.
 

·
Registered
Joined
·
2,475 Posts
It seems like there is some confusion about whether this is a Power stroke, or just a 7.3L diesel. If it is a power stroke, you are working with a computer controlled engine that will not have a fuel shut off solenoid. The fuel is "shut off" at the injector solenoids.
The older mechanical engines had a solenoid in the fuel pump to shut off fuel.

Which engine are we working with??

Your answer to the question about other ignition powered devices working also was rather unclear. Do they or do they not work with the key off??

Ford steering column problems are very common causes of conditions like this. So I am not surprised that the dealership went that route in repairing this. Ford uses a rack and pinion device inside the column. The pinion is connected to the key switch. The rack is connected to switches down at the base of the column. There are also a couple hundred other small parts inside the column as well.
 

·
Registered
Joined
·
1,381 Posts
it's a DI

the old IDI Diesel went away mid-year '94. The first 94 models were the IDI turbo - then the DI Powerstroke came out halfway in the year. So in 94 you can have a old-style injection system with a factory turbo. Everything from then is "new style". The 99 body style has some differences in the operation but is essentially the same hydraulic-operated electrically triggered injection system.
Since the engine can be shut off by pulling the fuse, it HAS to be power to the ECM, rather than dripping injecters/sucking engine oil in somewhere or whatever else could fuel the motor without the benifit of voltage.
I believe the ECM is ground-side switched - I have a CD at home I can check....but a short to ground on the control ckt could then keep the ECM powered up.
Have the Technical Service Bulletins (TSB) been checked? I would assume yes, since you went to the dealer, but from experience I know that nothing should be assumed. TSBs are sort of like "in-house" recalls for Ford dealers - not public, however, and you have to be carefull in how you apply them - sometimes what sounds like the "fix" doesn't do the trick - being out of warranty that gets expensive really quick. I haven't heard of run-on issues but I can check with some people who are more current in the field than I ( I have been out of Ford tech for about 2 years now).

deepmud
 

·
Banned
Joined
·
5,372 Posts
bennett said:
Pavemen said:
Do all of the other "key on" items operate (i.e. radio, heater) , or is it only the engine that keeps running?

Yep... everything elese works fine... just won't shut down.
I have thought about a switch but would like to find problem and solve it without another switch... but thanks

Noodle.. I can shut it down several ways, including crimping the fuel source. Pulling that #3 fuse is easy and takes just a minute once the hood is up. It is annoying. Part of the other problem is this is my dads trcuk and he is 76... he can't even remember where the fuse box is under the hood each time.. I labeled it and painted the fuse bright red.. still forgets and always calls me ..
the dealers are screwin him over though , I gotta figure this out.
What I was getting at is, do the "key on" items keeping operating after you remove the key? That could give you an idea at which end to start looking.. the key end or the engine end.
 

·
Registered
Joined
·
7,178 Posts
With the toyotas there is a switch and a piece of bar running to the pump, look at which direction it goes and push it!!

these guys are right though, its a fuel cutoff problem. If its not an auto you could try stalling it....

Or stop it from getting fuel some other how, look on the pump!
 

·
Registered
Joined
·
1,381 Posts
this is not a normal diesel - don't think "stop fuel", think more like a gas engine - "stop electricity". Pinching off the fuel line must take awhile to shut the truck off - the pump would draw from the fuel filter for awhile, then there are "fuel rails" cast into the heads. Each injector recieves it's fuel from the common rail, at about 40psi - each injector is controlled by the ECM, which operates a transistor on each injector - at a time and duration determined by the ECM, the injector opens, using 110 volts DC to get fast actuation ( the red wrapped looms under the hood have the 110v DC - don't poke these with a test light!) - here things get weird - there is another common rail in the head, with very high pressure oil in it - the spot in the motor that used to have a diesel injection pump/distributor in it now has a high pressure pump - the ECM sets the pump to put out anywhere from about 500 to 3000 psi - this is fed in a common "rail" again, another head casting, to the injectors. The 110 DC is applied to a valve, that lets in the high pressure oil onto a piston in the injector - the oil pushes down on the piston - which has been filled underneath by the 40 psi fuel rail in the head - the hydraulic advantage from the piston is 7 to 1 - let 3000 psi in, it pushes on the fuel at 21,000 psi.
There are 8 of these, 4 per side. Very very different than anything else out there.
OH, they use engine oil for the high pressure hydraulics - makes for a motor that is VERY finicky about oil types and change intervals. The first DI's were 12 quarts - the solution for oil aeration(rough idles) was to add 2 more - 14 qts.
deepmud
PS -I still will check my CD Factory manual for you tonight, but I suspect either a sticking relay, as mentioned by hightechredneck before ( I think he already knew all this stuff hehe) , or chafed harness, causing ground to stay applied even with the key off.
 

·
Registered
Joined
·
2,970 Posts
Discussion Starter #15
Robert said:
It seems like there is some confusion about whether this is a Power stroke, or just a 7.3L diesel. If it is a power stroke, you are working with a computer controlled engine that will not have a fuel shut off solenoid. The fuel is "shut off" at the injector solenoids.
The older mechanical engines had a solenoid in the fuel pump to shut off fuel.

Which engine are we working with??

Gettin back at ya.. thanks for the many replies
____________________________________

Robert: This is a "Powerstroke diesel" 1996 so I am assuming non mechanical and no solenoid shut off? right?
____________________________________
Deepmud.. I am thinking sticing relay also, could you check with your sources tonight?
___________________________________
hightechredneck: wher is that ECM...PCM relay located?.. I am still partially hung up on the fact that the Ford dealer put in a new ) plastic) rod that had teeth on it in the steering column. When I saw that I was thinking a mechanical shutoff? This is a 96 Powerstroke.
_______________________________________
DeepMud.. fist thing I checked with the dealer for him was the technical servie bulletins. The dealer checked in my presence and said there wer no recalls or bulletins.
________________________________________

Robert..follow up on your question..
[Quote"Your answer to the question about other ignition powered devices working also was rather unclear. Do they or do they not work with the key off??]
Answer:.. everything works OK when the key is off... the engine just stays running:confused: :confused:
Thanks gain.. I will be on PBB tonight for any follow up questions and I appreciate the help.

bennett
 

·
Registered
Joined
·
7,401 Posts
Damn, I wish I had that problem. I just put an open intake and a race/tow flip chip in mine tonight. 97 F350,CC,4wd. It is raining here tonight and I was able to bust the rears loose and pitch sideways:eek: at 65mph. I did not want to go home!
 

·
Registered
Joined
·
2,475 Posts
deepmud said:
this is not a normal diesel - don't think "stop fuel", think more like a gas engine - "stop electricity". Pinching off the fuel line must take awhile to shut the truck off - the pump would draw from the fuel filter for awhile, then there are "fuel rails" cast into the heads..
Good explanaition on how HUEI works.

By cutting off the fuel flow to the injectors, as in "pinching off a line", you can actually damage the injectors.
Secondly, if you get into electrical trouble shooting on the ECM circuits, throw away your 12VDC test light. The extra load put upon a curcuit by a test light can zap an ECM easily. Get yourself a good digital multimeter.
 

·
Registered
Joined
·
1,381 Posts
The EVTM shows the the control ckt for the computer control relay to only recieve voltage in RUN and START modes - not hot at all times - however, the power side of the relay IS 12v all the time, so if the relay stuck, that would keep things running. Bottom line, a little diagnosis is still needed, but I would try to find if the relay is being turned on by a chafed wire or bad switch - I guess the first step would be to see if pulling the relay shuts off the truck - then you could "throw parts at it" - just replace the relay. If the relay is the culprit, and a new one cures it, you're done. But it seems like things are never that simple somehow.
Anyway, the PCM relay is the one on the bottom of the set of relays on the right hand side of the box - the next one up is the fuel pump relay, the middle one is the horn - hey, you could swap the PCM and Horn relays - but your horn might start to stick hehehe. 2nd from the top is Trailer Marker relay, and the top should be empty, 'cause the manual says 4.9 liter only.
 

·
Registered
Joined
·
2,970 Posts
Discussion Starter #20 (Edited)
Thanks Deepmud... kind of fun to learn what I am dealing with now, great tips and help from pbb.
I swapped relays and like you said..things are never that simple. I thought I had it fixed as I started and shutoff the engine a half dozen times. On the sixth try, she stayed running.

Now I am thinking the diode could be feeding current backward as one poster suggested. When the diode is remove the engine does stop.

I tried several Ford dealers and I have to special order it:( :( .
once again the symptoms are as follows. I turn the key to the off position and the engine continues to run for 10-15 seconds, sometime longer. Wiggling the key or turning it on and off has no effect. Still have to wait the ten or fifteen seconds for it to die. I can feel the relays clicking. I tested each relay and they are operating fine. It has to be electrical .. diode is all that's left to check???

thanks for the help btw..

bennett
 
1 - 20 of 22 Posts
Top