# diesel shuts off when braking



## AintNoFun (Nov 26, 2003)

i was wondering if anyone has an idea what this could be before i bring it into the dealer... we have a 97 f450 diesel.... when my guys are driving the truck with or with a trailer (sometimes more with the trailer) the truck just dies.. and shuts off, like you flipped a kill switch. I can't figure it out for the life of me, hopefully someone can point me in the right direction.. thanks


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## sno-mover (Jan 12, 2002)

You have a chafed wire somwhere, probly near the fuel pump, and its grounding out and shuting the truck off. Did you have anything done to it recently.


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## PSDF350 (Jul 30, 2004)

was getting my truck serviced the other day and got to talking with a gentlemen. he mentioned he had a similar problem. what it was was something was overheating (don't know what) once it was replaced it has never happened again. sorry i cant help more but i am no mechanic


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## AintNoFun (Nov 26, 2003)

sno-mover said:


> You have a chafed wire somwhere, probly near the fuel pump, and its grounding out and shuting the truck off. Did you have anything done to it recently.


i just had it serviced, trans, rear, brakes, oil, everything.... but the problem didn't happen for a week or 2 after... i dunno... im gonna bring it to the guy that works on all my trailers see if its maybe the electric brake controller? its weird, it didn't do it all day today, a few days ago it happened 2 and a week ago it happend 6 times.. im stumped.. i just want to get it fixed before the snow starts falling.. any other ideas guys? thanks again


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## Ggg6 (Oct 14, 2003)

Sounds like a (CPS) Cam Position Sensor. See if it tends to happen when the engine is hot, then it will start back up after it cools, and die again when its hot. It is not uncommon on the PSD's Do not pay over $100 for one. Best $ is usually at Navistar but you will need the engine s/n. It can be found just above the oil filter stamped in the block. Let me see if I can find you a part #.


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## Tarkus (Nov 19, 2004)

I think it is in the injection pump myself. When you take foot off of throttle at speed the pump shuts off fuel until engine returns to near idle speed. Yours is never turning it back on it seems.


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## Aspen Snow (Aug 6, 2000)

It's the brake controller. We had the same problem with our 96' 7.3 F-350. We traced it to the brake controller. Replaced it, its been fine since.


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## Ggg6 (Oct 14, 2003)

Tarkus said:


> I think it is in the injection pump myself. When you take foot off of throttle at speed the pump shuts off fuel until engine returns to near idle speed. Yours is never turning it back on it seems.


The Powerstroke diesel does not have an injection pump.

AintNoFun-Other then in the title you make no mention of braking, or a brake controller. In your description of the problem you do not mention the brakes, do you think they are a possible cause and if so why. I see Aspen Snows point but we could use some more details. Like is the problem only happening when you use the brakes, as far as the trailer goes does it still happen if the trailer wiring is unplugged. Or what if you tow a trailer without brakes or just surge brakes. How about engine RPMs does it only die at idle or anytime. Since you say it acts like a switch has been turned off that makes me think it is electrical. If it were fuel it would spit and sputter before dieing. Just thinking out loud.


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## AintNoFun (Nov 26, 2003)

Ggg6,

It only happens when braking, but its so sporadic. Its def. electric, not the fuel pump or anything in the fuel system. And it happens at any RPM or any speed. We've driven around with the trailer unplugged and while it doesn't happen as often it still happen. It hasn't done it in a few days now but with the snow coming soon I cant have it acting up again. I got an appt. on tuesday with my trailer guy, well see.... Think i should just unplug the trailer brake controller. thanks for all the help so far guys.....


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## Tarkus (Nov 19, 2004)

Ggg6 said:


> The Powerstroke diesel does not have an injection pump.


They did not have common rail then as I recall and even if they did they still shut fuel off via "rail" injectors untill near idle speeds when throttle is released.


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## 82F100SWB (Dec 12, 2004)

Powerstrokes hae never had an injection pump. Nor do they have common rail, they're HEUI, a wonderfull little Cat system that Navistar uses under licence.

Anyhow, they do shut off the injectors until idle speed is reached when you come out of the thottle.
It does sound like a CPS problem, but, my uncle had the same problem with his 00 F350 when it was new, and it was his trailer brake controller also. It makes absolutley no sense to me, but, it's worth a shot.


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## Tarkus (Nov 19, 2004)

82F100SWB said:


> Powerstrokes hae never had an injection pump. Nor do they have common rail, they're HEUI, a wonderfull little Cat system that Navistar uses under licence.
> 
> Anyhow, they do shut off the injectors until idle speed is reached when you come out of the thottle.
> It does sound like a CPS problem, but, my uncle had the same problem with his 00 F350 when it was new, and it was his trailer brake controller also. It makes absolutley no sense to me, but, it's worth a shot.


They have to have something to inject fuel under several thousand PSI into cylinder. You might call it something else but it has a "pump" of sort to build the pressure and a injector to get it into the chamber.


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## Dwan (Mar 24, 2004)

aintnifun,

I may have missed something but it seems we are searching 2 different motors here. is it a "IDI" or "DI" 7.3 both were available in 94. 
If it only happens when you are using the brakes then I would first check every ground connection on the truck for a corroded or loose ground. If you have a wireing diagram then loook for a comman ground conection between the fuel control modual and the brakes. Next backtrack everything that was done sence the last repair before you had a problem.

Without having the truck it is so hard to troubleshoot I would say it is next to imposable. But you may be lucky and find someone that has had the same situation.


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## Ggg6 (Oct 14, 2003)

AintNoFun- most certainly unplug the controller and see if it still acts up. But depending on how big of a trailer you have this might not be how you want to tow. I also agree on the common ground theory, I have seen some real weird stuff on these trucks caused by faulty grounds. Clean and tighten all the ground straps you can find; body to frame, body to engine, battery to ground, engine to frame, etc. The symptoms are very similar to bad CPS, and CPS symptoms are not always the same. If you can, borrow a spare CPS from someone and see if it cures your problem. Changing the CPS is only a 15 minute job. Note; use a 6 point 10mm wrench or socket for the CPS bolt NOT a 12 point it is very tight from the factory.


As far as discussing IDI v/s DI, or common rail v/s HEUI I will be happy to do so. But to be polite to AintNoFun I would rather do it in a separate thread so we do not "hijack" this one. I am not trying to be difficult just respecting the topic at hand.


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## Crumm (Nov 5, 2003)

Tarkus said:


> They have to have something to inject fuel under several thousand PSI into cylinder. You might call it something else but it has a "pump" of sort to build the pressure and a injector to get it into the chamber.


They have a high pressure oil pump that supply's oil to a piston in the injector. So yes they do have a "pump" that in turn supply's high pressure fuel into the cylinder.

Tarkus, Since you have no idea how the PSD fuel system works why do you feel it necessary to just throw ideas out there on something you have no idea about? 864 posts when you have only been a member for a month shows that you must have an opinion on about everything. You should stick to what you know rather than sending a guy on a goose chase for something that his truck does not even have. Just my .02c.


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## ADLAWNCUTTERS (May 24, 2001)

sounds like the cps. even if is not that they go so offen that you should have a spare. go to an internatinoal dealer and pick one up ,it's cheaper than the ford dealer.


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## Tarkus (Nov 19, 2004)

Crumm said:


> They have a high pressure oil pump that supply's oil to a piston in the injector. So yes they do have a "pump" that in turn supply's high pressure fuel into the cylinder.
> 
> Tarkus, Since you have no idea how the PSD fuel system works why do you feel it necessary to just throw ideas out there on something you have no idea about? 864 posts when you have only been a member for a month shows that you must have an opinion on about everything. You should stick to what you know rather than sending a guy on a goose chase for something that his truck does not even have. Just my .02c.


I know more about that diesel than you think and they ALL work on the same principles, they just go about it differently as the timing and duration of injection controls output of engine. On some it is does by a pump with individual injection lines and some with common rail with controlable injectors but again it all uses the same principle to control output and engine RPM. The fuel is being cut off here and not being restored at a idle speed. Work the problem and do not ad BS to it like you do.

You should also stick to not trying to insult people. People that do that generally do not feel good or are very insecure about themselves and/or knowledge they have so they act out against others and put them down to make themselve feel better. You do not want to look like you are in that group do you? You seem to be more concerned about my number of posts than I am ( I go through posting spurts and not that it is your bussiness anyway but there is a lot I do not respond to also). You have issues you need to resolve


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## berkplowguy (Dec 15, 2004)

Ggg6 said:


> Sounds like a (CPS) Cam Position Sensor. See if it tends to happen when the engine is hot, then it will start back up after it cools, and die again when its hot. It is not uncommon on the PSD's Do not pay over $100 for one. Best $ is usually at Navistar but you will need the engine s/n. It can be found just above the oil filter stamped in the block. Let me see if I can find you a part #.


It sounds like the crank postion sensor. It ran me about 450 after all The Bull-S testing, part was 150 they got me good on finding the problem.


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## Plow Meister (Oct 16, 2001)

I wouldn't bet on the crank sensor just yet. It is, in most cases, the common suspect since they are prone to going bad. If it IS the CPS than you can get one from an International dealer for way less than Ford. Plus, it is a snap to replace. You just need a 10MM wrench and about 20 minutes of your spare time. I have replaced mine 3 times now. Make certain to put anti-sieze on the replacement CPS. Makes it easier to replace the next time around. If you want, I will look for the IH part number. It should cost about $129.00 or less.


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## Plow Meister (Oct 16, 2001)

Tarkus said:


> I know more about that diesel than you think and they ALL work on the same principles, they just go about it differently as the timing and duration of injection controls output of engine. On some it is does by a pump with individual injection lines and some with common rail with controlable injectors but again it all uses the same principle to control output and engine RPM. The fuel is being cut off here and not being restored at a idle speed. Work the problem and do not ad BS to it like you do.
> 
> You should also stick to not trying to insult people. People that do that generally do not feel good or are very insecure about themselves and/or knowledge they have so they act out against others and put them down to make themselve feel better. You do not want to look like you are in that group do you? You seem to be more concerned about my number of posts than I am ( I go through posting spurts and not that it is your bussiness anyway but there is a lot I do not respond to also). You have issues you need to resolve


I agree with Crumm, Tarkus doesn't know how the PSD fuel system works. He has the theory down but not the practicals. It does use high pressure fuel but it is created in the injector by means of high pressure oil. The HPOP (high pressure oil pump) forces the fuel into the combustion chamber. It is controlled by the PCM (power control module) which takes readings from various sensors. Mainly the CPS (crank position sensor) and the throttle input from the go pedal. The go pedal doesn't have a cable attached to it. There is a potentiometer attached to it that measures the pedal position and tells the PCM how much engine throttle to produce. Let me know if you want me to go on.


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## Tom Smith (Nov 8, 2003)

i would say its the brake controller... i was talking to a guy at the local trailer dealer and he was talking about something similar... he removed the controller and problem was solved


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