Isata 5 - Cummins 6.7 changed fuel filters. now it won't start

[daveinthekeys]

Chaps2018 sorry I forgot to answer. I used a code reader that showed two errors but it would not tell me what they were. I guess I need a more advance reader.

And while the check engine light is on after I turn on the key and all the other lights go off. I also see that this happens in my gas powered truck.

BTW, I did go to NAPA this morning and they do not have the OEM filters. So it is either drive 2.5 hours to Miami and 2.5 hrs back. Or order again from Amazon probably with my order for a code reader (and a new lift pump?).

[daveinthekeys]

I hooked up my portable diesel fuel polisher which pumps 40 gallons per hour. I attached it between the on-chassis filter and the fuel tank and pumped form a five gallon container.

It fired up and ran for as long as I ran the pump.

I then reattached the fuel tank line to that filter and the it stopped after about 10 seconds.

Do you really think it could have run without a lift pump before the filter change? I have read that it is possible.

[Witch Doctor]

Before you pull your hair out and spend alot of money, I would call your tow service, tell them you think you ran out of fuel. There pretty smart about these things most atleast. He could let you know if it is the pump. Do You have Coach Net or Goodsams? they both offer this service,,,,

[ICanFixIt]

What are the codes that you pulled from the reader? You can google them to see what issue they point to. Sometimes they actually can help narrow down the troubleshooting process.
Based on your last test using the fuel polisher it sure does point to the issue being something with the pump. Now it needs to be determined if the pump has failed or is the computer failing to tell it to turn on. Have you cleaned the connector at the bottom of the water separator? I have also read that the engine can run without the pump in the tank working so it is possible you've had the problem prior to changing the filters.

[Coolbaldguy]

I dont think it has been mentioned yet, but does this truck have an emergency fuel cut off switch? Much like what are in the trunk of most passenger cars in case of an accident. If a hard impact or roll over occur this switch will shut off the fuel pump. It can be reset by pushing a button. I have owned several Ram trucks and I would think there would be one located somewhere on it. Just a thought that might be worth investigating. Good luck with it.

[daveinthekeys]

I agree that because the pump does not run does not mean it is broken. I could be that the PCM is not telling it to run because of some fault.

I do think that sending power to the fuse should power up the pump though. I believe that connection would be after the PCM. At least it is that way on my gas powered 2016 Ram 1500. In some ways I am glad that putting power to that fuse did not power up the pump. As then it would be a more difficult problem than a simple broken pump in the fuel tank for certain.

My code reader comes tomorrow. However, the check engine light is not supposed to disable the vehicle. That warning is for "minor" things. Or so they say.

I sprayed degreaser, then water, then rubbing alcohol on the electrical connector leading to the water sensor under the on-chassis filter. This connector did get soaked with diesel. But it is clean and dry now. Would water in that filter shut down the pump? Would those connectors being wet from diesel close the switch and tell the PCM water was present and then the PCM would shut down the pump? Maybe. But in all the many Utube videos and written instructions from Chrysler, MOPAR and people who have changed their own filters and video'd the process. Nobody had that happen. And now my connectors are bone dry and clean as a whistle under the canister of the filter of the on-chassis filter. I can not speak of other wires and connectors. Though they should not have been impacted by my filter change.

I think what has happened is that the lift pump in the tank had failed before the fuel filter change. And if I could somehow get it all perfectly primed from the tank to the engine it would run again. Then I could take it to Miami or somewhere civilized. I wish I had a big hill nearby to get the tank higher than the engine's pump and gravity could do its work. But The largest hill in The Florida Keys are probably the swollen mosquito bites on my legs. If this was Gilliagan's Island I would lash the fuel polish system on the running board and go.

Regarding the possibility of an emergency off switch or something similar. I don't know of one. And it would not normally go off if I ran out of fuel driving it. Replacing the filters is no different from running out of fuel as far as the PCM is concerned. The user manual says if I run out of fuel. That I should put fuel in and start it up (page 164). The instructions for priming after new filters is turn the key on for five seconds four times. I can not explain this discrepancy but either way my dozens of times of key turning and engine cranking over several days with have done the job. Rather I think it is a manifestation of an old problem. And the most likely is that the lift pump in the tank had been inoperative before the filter change. Though nothing would make me happier than to be wrong about this. I really don't want to drop that tank. And I am doubtful that I can find somebody locally to do this job. The Central Florida Keys are still suffering from the hurricane's displacement of businesses and their employees. Many, many people have left because they have no place to live. Many businesses have closed, even if their building survived, because they have no employees.

I believe that I may need to solve this one myself. Please keep the ideas and help coming. I really appreciate all of the input. Thank You

[Delco Bobby]

Originally Posted by daveinthekeys

I agree that because the pump does not run does not mean it is broken. I could be that the PCM is not telling it to run because of some fault.



I do think that sending power to the fuse should power up the pump though. I believe that connection would be after the PCM. At least it is that way on my gas powered 2016 Ram 1500. In some ways I am glad that putting power to that fuse did not power up the pump. As then it would be a more difficult problem than a simple broken pump in the fuel tank for certain.



My code reader comes tomorrow. However, the check engine light is not supposed to disable the vehicle. That warning is for "minor" things. Or so they say.



I sprayed degreaser, then water, then rubbing alcohol on the electrical connector leading to the water sensor under the on-chassis filter. This connector did get soaked with diesel. But it is clean and dry now. Would water in that filter shut down the pump? Would those connectors being wet from diesel close the switch and tell the PCM water was present and then the PCM would shut down the pump? Maybe. But in all the many Utube videos and written instructions from Chrysler, MOPAR and people who have changed their own filters and video'd the process. Nobody had that happen. And now my connectors are bone dry and clean as a whistle under the canister of the filter of the on-chassis filter. I can not speak of other wires and connectors. Though they should not have been impacted by my filter change.



I think what has happened is that the lift pump in the tank had failed before the fuel filter change. And if I could somehow get it all perfectly primed from the tank to the engine it would run again. Then I could take it to Miami or somewhere civilized. I wish I had a big hill nearby to get the tank higher than the engine's pump and gravity could do its work. But The largest hill in The Florida Keys are probably the swollen mosquito bites on my legs. If this was Gilliagan's Island I would lash the fuel polish system on the running board and go.



Regarding the possibility of an emergency off switch or something similar. I don't know of one. And it would not normally go off if I ran out of fuel driving it. Replacing the filters is no different from running out of fuel as far as the PCM is concerned. The user manual says if I run out of fuel. That I should put fuel in and start it up (page 164). The instructions for priming after new filters is turn the key on for five seconds four times. I can not explain this discrepancy but either way my dozens of times of key turning and engine cranking over several days with have done the job. Rather I think it is a manifestation of an old problem. And the most likely is that the lift pump in the tank had been inoperative before the filter change. Though nothing would make me happier than to be wrong about this. I really don't want to drop that tank. And I am doubtful that I can find somebody locally to do this job. The Central Florida Keys are still suffering from the hurricane's displacement of businesses and their employees. Many, many people have left because they have no place to live. Many businesses have closed, even if their building survived, because they have no employees.



I believe that I may need to solve this one myself. Please keep the ideas and help coming. I really appreciate all of the input. Thank You

Please don’t be insulted but when all else fails, use a hammer. That method has worked for me a number of times as recently as last month. Of course not on an expensive RV.

No diesel mechanics/shops in lower keys?

[Whalenss]

Daveinthekeys, Any success?

[chaps2018]

Can u post the error codes?

[daveinthekeys]

I got it running. I was able to push fuel through both filters starting at the on-chassis filter to the engine pump using my fuel polisher. I then ran the truck few a few seconds to get the injectors primed.

Then I sucked fuel from the tank to the on-chassis filter using a suction pump.

Now I had a completely filled/primed system with the tiny exception of the few ounces of fuel that i lost connecting the fuel lines again.

It runs fine now. I still need a lift pump. But I can do that later. From what I have read there should no problem driving it 2.000 miles and having it fixed near my summer house? It is time to head North.

I still have a check engine light and my code reader has yet to arrive. I will post them soon. That is unless they go away on their own.

So, I need a lift pump at 14,800 miles or sooner as nobody knows when that pump failed. It seems the pumps main job is to reprise the system after one runs out of fuel or changed the filters.

Is it possible that this pump, pushing such a long distance through some small (about 1/4" ID?) lines is getting too much resistance (to quote Crosby Stills Nash & Young)

[Brewhedd]

Originally Posted by daveinthekeys

For those of you who have dealers within a reasonable distance. I have no issue with using them. However, in my case, I live in the middle of the Florida Keys. We do not have those kind of services.

Also, changing fuel filters is nothing like rocket science. I have done it many times on many vehicles. For this particular job it was not about saving money. It was about not driving 4.5 hrs each way to get this job done. I will also say that having some ability to get oneself out of trouble has paid off in the past and each mechanical job learned helps with the next one for myself, or others that need help.

I hear you. I didn't mean to imply that you are wrong for doing your own maintenance. Being so far away from service would probably have me doing the same thing.

[jtesta1]

Just fill your filters with fuel before installing them. They hold a lot more fuel than you think.

[chaps2018]

Glad to see this came to a decent ending point. I am very frustrated with the idea of not knowing when your lift pump fails. I carry a spare set of filters just in case I get bad fuel and it would be pretty bad to find out on the side of the road that my lift pump doesn't work.

I do have a question though- about the symptoms of a bad lift pump-- did you ever have any trouble accelerating or going over hills before you got to your present destination?

Please keep us posted

[DieselDrax]

Originally Posted by daveinthekeys

It seems the pumps main job is to reprise the system after one runs out of fuel or changed the filters.

No, the main purpose is to ensure the injection pump is getting sufficient fuel. Some earlier trucks lacked in-pump or on-frame pumps and relied on the injection pump to suck fuel, they weren't really meant to do that and a lot of injection pumps failed early on due to insufficient fuel and aeration. Trucks have lift pumps to keep the injection pump happy and alive.

Is it possible that this pump, pushing such a long distance through some small (about 1/4" ID?) lines is getting too much resistance (to quote Crosby Stills Nash & Young)

No, the lift pumps are doing what they were meant to do. If yours failed then it was either defective or was somehow damaged. Some lift pumps have been damaged by trying to pump gelled fuel in the winter due to fuel not having the necessary additive to prevent gelling, the pump then tries to pump sludge and starts to scream before dying.

I would run as little as possible without a lift pump, if the distance/height between the tank and injection pump is too great then you will damage your injection pump or greatly shorten its life.

[Bill Davis]

Originally Posted by chaps2018

Glad to see this came to a decent ending point. I am very frustrated with the idea of not knowing when your lift pump fails. I carry a spare set of filters just in case I get bad fuel and it would be pretty bad to find out on the side of the road that my lift pump doesn't work.

I do have a question though- about the symptoms of a bad lift pump-- did you ever have any trouble accelerating or going over hills before you got to your present destination?

Please keep us posted

I had a bad lift pump on my diesel pusher. It was a 400 Cummins. It was only an issue when I was pulling long mountain passes out west. On the flat lands it would run all day long without a problem. After a few miles of pulling it would start to loose power. It never completely stalled out but it made for a long day.
At the time I was pulling a 24 foot trailer with a car and motorcycle inside, so a lot of weight plus it was a 40 foot RV. We stopped at a Freightliner dealer in Montana and they diagnosed it and replaced it under warranty while we spent the day riding the Harley around Yellowstone.

I feel your pain with having to deal with repairs in the keys. I lived on Ramrod key and worked at the GM dealership for years in the 80s.

[hook47]

Had 2 Duramax P/U's. Lots of folks were adding external lift pumps. Might a separate external lift pump provide you with a solution till you can replace internal one?

[CHICKDOE]

yippee! i'll bet you are happy! you had quite a struggle.

a few posts ago you questioned whether the pump was bad or if the computer was not telling it to run. even tough you have it running, you still haven't found the true cause. when you do get around to getting the pump issue resolved, would you please post the results as i'm sure there are a lot of people who would like to know.

[Coolbaldguy]

I dont think anybody mentioned that when pre-filling fuel filters, always block the center hole and fill into the sides of the filter. Pouring fuel directly into the center you run the risk of some debris getting into the "clean" side of the filter. This can cause VERY expensive repairs to injector pumps or the injectors themselves. Glad you got it going!

[daveinthekeys]

I filled the front filter with the element in place using a long funnel and a bottle. Thus it was filled the same as if the pump had pumped it. ie from the outside.

My check engine light went off on its own. Now I don't have to read the instruction for the new code reader just yet. Though I do wonder if it would read fuel pressure?

It is true that the lift pump can assist the high pressure pump on the engine. This is especially important for people going for high horse power. I have read that some people are going for 800hp and putting high capacity lift pumps to assist the high pressure pump which in our case is a CP3. It is purported that a stock motor would not need to lift pump other than to prime the system. There are conflicting opinions on this.

However, this CP3 pump is also used on the Duramax and that truck has no lift pump. I think the question is how much restriction is the dead pump creating. And how many miles ago did it die?

The CP3 will handle "normal" power output and usage according to my local "Certified Cummins Mechanic", a local mechanic that seems pretty knowledgeable, and the Cummins User Forum has mentioned it by several people.

I have no idea when the pump failed. It could have been thousands of miles ago. I have never had any symptom. However, I do drive like I have an egg on the accelerator and strive for 10 mpg at about 62 mph.

One reason for my easy driving is that I wonder about the long drive shaft and the general heft of the beast. I mean why push it?

Yesterday, once it started, I let it idle for 30 minutes. Then I changed the oil. I restarted it and started packing. Today I took it for a test drive at highway speed. No issues. I even did some heavier acceleration as I want it to fail next to my house. If it is going to fail. And I suppose it still might fail between The Florida Keys and Wisconsin via Eastern Maryland. But no matter where that happens. I will be in a place that has more opportunity to find help than the Central Florida Keys. (Even before the Hurricane we had limited resources.)

I did call my dealer, that I purchased the coach from and tried to schedule an appointment. They are booked out until early July. Once I explained my problem. I was told that I should go to a Dodge/Ram dealer for the warranty work. They don't do this kind of work. I don't know if that is all Dynamax Dealers or just North Trail RV in Ft Myers. Though I will be checking that out.

I don't know how many of you have found general purpose dealerships that work on Super C Motorhomes.

In 2014 - 2016 I owned a Ford F550 based Super C (Thor Chateau 33SW). I started calling dealerships for an oil change in Miami and finally found somebody (Palm Bay Ford) in Palm Bay FL which is kind of South of St Augustine. They are right off the highway, did it while I waited... were pleasant and inexpensive. I highly recommend them and returned each Spring and Fall for an oil change during our migration from Wisconsin to Florida.

I have not tried calling Ram Dealers yet. I wonder if they get paid any extra for warranty work on a two tank RV that requires a huge lift (our axles are about 24 feet apart and we are taller than many of their work spaces. (Palm Bay Ford just crawled under there with a creeper and a drip pan.) On the bright side if I get home I can try places.

Another option, is to forget the warranty. As was mentioned many people are installing external lift pumps... Meaning outside of the tank. The "Certified Cummins Mechanic" said that every time he replaced one of those pumps in an motorhome it was because of algae growth in the fuel tank. Which would suggest a plugged pump. I did not open up the filter to look. I still have it and will do that and report. Though I might just take it to Wisconsin to cut it open. I expect to get there in early July.

The external pumps have higher capacity than the stock in-tank pumps. And some say more importantly uses external filters. I don't get why that is superior? Since the CP3 is always sending a ton of unused fuel back to the tank. The system is always being fuel polished. I also wondered about the algae comment as I thought water was required to grow that problem. I have seen it on boats which generally have tank vents that open to the air. These tanks breathe in warm moisture and condense it on the tank walls on cooler days/nights.

But I assumed our fuel system's were air tight like a gas system (at least I think gas systems are air tight). I watched some install video of these external systems and then looked at all the wires, plumbing, hydraulics and such that are not present on the basic Ram 2500 or 3500. I am sure it can be done. But not quickly, laying on my back in the dirt. This job really needs a lift.

There is also an internal pump that is a drop in replacement that is purported to be superior, at least in fuel flow. I think our long thin fuel lines probably give some resistance also. Some of the external pumps are using 1/2" fuel lines.

Any way I learned a lot more than I wanted to. I will post a final when it is fixed. Or sadly an intermediate, if I get stuck someplace.

I am pondering whether to pack the pumps and tubing (12 volt diesel fuel pump, hand pump suction pump (like for sucking out oil), and 5/16 plastic tubing from Home Depot their house brand Everbilt. The Home Depot 5/16" tubing makes an airtight seal onto the fitting that normally connects the on-chassis filter. Finding that exact fit was lucky. This tube makes sucking fuel possible. Keep in mind that normally you buy tubing based on the inside diameter. Perhaps other 5/16" plastic tubing would not have the outside diameter to work with the special connector with clips and fancy stuff. The connection on the filter itself is just a pipe. I found 3/8" fuel line and a clamp worked great. If I was taking off in my boat. I would pack it. But the RV is going to be traveling through civilization and this stuff stinks like diesel.

Anyway I've gone on too long and probably most people have given up on this saga long ago.

Thanks for the help and general encouragement.

[caseymyers]

I presume you'll be going up through Tampa? Google commercial truck RAM dealers along your route north. Doesn't have to be a Dodge P/U dealer, the commercial truck guys that sell the 5500's and bigger and have the equipment and lifts for such work, is what you are looking for. I helped a couple of I5 owners find such dealers in LA for example. My locale San Diego RAM dealer won't work on mine either, I have to take it to a truck place. By the way a Cummins repair facility will take you too, just make sure your warranty will work with that facility, they might even make the warrant approval calls for you. Good luck.