6.4 running rough - Diesel Forum

clarence1984 · 10-22-2008, 07:42 PM

My 6.4 starts very quickly and when it's cold it runs great smooth as a baby's.... well after about 15 minutes of it running the truck starts shaking. Sometimes it can run for an hour and this does not happen it seems spuratic. Another faulty injector? We ran biodiesel in the truck only 5 percent last month for a couple of the tanks but forgot to drain it before taking it to the dealer so they said they couldn't determine how much diesel was really in the tank and wouldn't do the work. So i replaced the fuel pump and #3 injector myself we put about 1000 miles on it so far with zero problems until now. Any ideas on what is causing this. When the truck was running rough i ran my auto tap and saw the fuel rail pressure was 4 to 6k psi which isn't a change from when it's running smooth. Any ideas? We did drain the biodiesel out totally and replace fuel filter too and put in fresh diesel before the injector replacement.

i'm taking it to a new dealer 200 miles away from me this next week but i want to be prepared with some information.

clarence1984 · 10-22-2008, 08:27 PM

a friend of mine who's a mechanic at this place says it sounds like the valve that on the high pressure pump might be sticking because of the bio and putting the fuel back in the return instead of to the injectors this would be a reason why the pressure is only 4 - 6 k psi

GrampyJim · 10-22-2008, 09:40 PM

Quote:

Originally Posted by clarence1984

a friend of mine who's a mechanic at this place says it sounds like the valve that on the high pressure pump might be sticking because of the bio and putting the fuel back in the return instead of to the injectors this would be a reason why the pressure is only 4 - 6 k psi

Well, Ford gives us all a blessing for up to 5% bio-diesel.... so I fail to understand your dealers reluctance to work on the truck like that... What I also fail to understand is your thinking.... Making a major change (such as fuel supply/quality) just before having a concern investigated has a very real chance of being counterproductive....

4000 to 6000 PSI of fuel rail pressure is a good reading... but so much depends on what you have the truck doing at the time.... FRP is a moving target and can vary from 4000 PSI (perhaps even a touch lower) to over 20,000 PSI.... This isn't a good diagnostic aid unless you are using active commands like the high pressure fuel test.... And even then, the test can ask more questions than it answers.

clarence1984 · 10-23-2008, 01:05 AM

alright well that's what i figured. Dang I was hoping a simple unplug and swap of a part. i'm so tired of it always being something i have to tear the whole engine apart to fix like the injector. It was very straight forward just the #3 takes a long stinkin time to take everything apart and take it out and then put the new one in and put that pesky perfect fit valve cover back in. The bolt on the back of that sucker well ... sucks you just have to double up on the extensions and good swivel i guess like i did then stick your hand back there and finger tighten it back in when your done. I need a code to see what is really going on though. I tightened the stainless tube to spec and the bolt that holds the fork against the injector. Not sure what is going on since it runs smooth then starts acting up after about 15 min. Then the thermostat stuck open today not sure if that is a problem everyone said the temperature of the engine means nothing though to the fuel.

Jcard · 10-23-2008, 09:30 AM

Every time I have lost an injector I got smoke, lots of it. More so before the truck warms up.
3 injectors by 32,000 miles and running good ever since.
Not sure if it maks a diff but adding power service every tank now instead of every couple thousand miles.

clarence1984 · 10-23-2008, 01:32 PM

that's what i figured. I don't get it why so many injectors? We only ran 5 percent bio through this truck for two full tanks. So it can't be that. The original dealer and service center that i bought this truck from refused service because they said this truck is a can of worms. I got so screwed from them. It sat there for 4 weeks. I paid for extended service when i bought the truck to have a rental when it was down and they told me they would not supply it i need to pay for the vehicle out of pocket. So after 32 days of the truck sitting there they wrote me a estimate for all new injectors, high pressure pump, all new lines, lower pump, and tank for 7200 dollars. Said they cracked open the water pet **** and seen gelled bio in it. I said well it's freezing outside and the water trap is made to trap crap. We are allowed 5 percent he said well the sample i took i couldn't smell diesel. I said well run the water and crap out of the trap or take a sample from top of the engine out the cooler it is pure diesel no additive. He said well we can't determine how much you put in there so we are voiding your trucks warranty. I said that's bull**** i'm coming to get it. I had a tow truck driver come and get it and when it came back the hood was dented because the dealer slammed the hood down and the service tech didn't put the vacuum pump back down off the top of the engine. I was po at this point i called them and said what is this. After getting it home i tried to start the truck and the starter was disabled. (i know now how to fix this without the ford ivs) Also all the split loom tubing from the main harness was taken off and the passenger side fuse box was melted. I called the manager of the store and he said man i'm sorry you bring it back and we'll make it right i'll stand there and make sure while they fix it. So i paid out of pocket to have it go back and the dealer said it may take a couple of days for it to get in because we are slammed. So i went on vacation got back 2 weeks later and called the dealer told him i was back the dealer said oh we still havn't got the truck in sorry.
I said well we talked and you said to bring it back right away. He said i'm trying her man ... so i called the store manager again and said hey what is going on i'm getting the run around it's been a month and a half and my truck hasn't even got looked at really. So the store manager calls me back the next day and says come and get it were not going to fix it. Don't bring it back it's a can of worms. I call ford. Detroit told me dealers are private businesses take it somewhere else. I said the next closest one is 200 miles from me. You guys gonna pick up the tow tab this time. He said give all the towing receipts to ford and they'll pay them all. So I had the truck towed back home. Replaced the injector myself and the fuel pump which was crappin out. Went to a performance pump with 3/4 stainless lines. The truck run beatiful until driving down the road and black smoke again. I'm sure it's another injector but why so quickly and this time with a rinsed out system and pure diesel.? It's going to the shop this sunday to have it looked at because my genesis system with latest update, autotap, and my equus machine can't get any codes off this machine, in fact when i try to connect it says please enter vin because it's evidently not in the pcm anymore. I'll keep you guys posted as to what happends.

also if the starter disables. The truck does it through the security system.
Turn the key off 0 and on 2 8 times quickly within 10 seconds and make sure you end in the 2 position your door locks will cycle and now you turn the key to 3 (start) and the truck will override the starter disable.

rlchv70 · 10-24-2008, 10:26 AM

Why would you try to mess with the truck yourself if it is under warranty? Easy way to void the warranty. The injectors require a special procedure to replace.

This guy is smelling more and more like a troll:

why so many injector problems

clarence1984 · 11-12-2008, 04:03 PM

not sure i know what you mean by troll. The truck is still in service the dealership i took it too has been very friendly but is really taking there sweet time finding out what's wrong. They said the fuel did not have bio in it when they tested it and it seemed to have too much additives that fueling stations often use to keep diesel from gelling and keep water out of the tanks. I figured this may be the problem. 700 bucks to drain out old crappy diesel and put in new. But the problem has not gone away yet is what they said and they are still diagnosing the truck. The problem with alot of dealerships is the telephone game problem. The brains (diesel tech) tells the rep to call the customer and give them an update and since the rep really doesn't know anything about the truck but what the tech told them they are extremely limited and often make there own interpretation of what is going on with the vehicle. Too bad the dealership doesn't allow the customer to talk directly to the diesel tech. I think I could get answers to all my questions quickly then.

clarence1984 · 11-12-2008, 04:31 PM

I called the dealership today to get an update and the rep said that I have to put the stock fuel pump in (which doesn't work) and put new lines on the truck. In order for them to even fix the truck. They said they can't figure out what is wrong with the truck and the performance fuel pump on the truck is putting out too much pressure (which seems strange because the truck has a pressure regulator built into the fuel filter housing). Which let's fuel go back to the tank if it's more than 3psi.

They did mention the best choice would be to put the stock fuel pump back in and put some new lines from the tank to the pump. So after talking to the wife this maybe the best choice. Isn't there any performance fuel pumps out there for the 6.0/6.4 since they use similar fuel pumps?It's hard to believe there is no compatible pumps that are stronger than stock. The rep also mentioned that they can't determine if the fuel pump is the problem. it's just a process of elimination. So i'm at a loss. Considering I don't want to pay for every single part on the engine out of pocket when it goes and if you think about it you can relate every power train problem to an aftermarket fuel pump.

BlueMuleTrucking · 11-12-2008, 06:07 PM

The dealer I go to lets me speak to the tech if I ask.

clarence1984 · 11-14-2008, 01:33 PM

the rep i was talking to was an idiot and the one they referred me too helped out a ton. I got the truck taken care of now and there is a clear process of repair. I even got to talk to the tech. He said it looks like there is a small leak in the high pressure pump internally. It seems to be showing inconsistent pressure readings. he said it's has an oscillating fuel pressure when it's ramped up and at idle it's going up and down 2000 psi at all levels. He said it hits all levels but it's just jittery and causes the engine to run rough. He said since i have a performance pump he is unable to diagnose it correctly though. He mentioned that I can put the stock fuel pump back in and they should be able to diagnose and warranty problems with the high pressure pump. So that's good to hear. Also on another note he did mention that the fuel cooler pump (the pump that pumps the coolant through the fuel cooler heat exchanger is not a necessity to the truck. I told him it wasn't working and he said no big deal doesn't make a difference. Glad I finally got some clear answers and a friendly attitude. I drove the truck 50 miles last night and it does buck a bit in overdrive a bit. Clearly because of the engine running lean. Just wanted to give everyone an update and let you know ford is pulling through for me.