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

[daveinthekeys]

I changed both primary and secondary filters. First, I did the one on the engine, and then the one under the coach. Doing these at the same time presumably drained all the fuel from the lines? I noticed quite a bit of fuel drain after the under the coach filter, closest to the fuel tanks, was removed. I am wondering if I should have done them sequentially and that way started the engine between filter changes? On the other hand, people do run out of fuel on the highway. So this would be solvable.

The owners manual says, if you run out of fuel, "Turn ignition switch to the start position to engage starter for one second, return ignition switch to run position. This will activate in tank fuel pump for approximately 15 seconds. Repeat this process twice."

My key does not work that way. I can not turn off the starting operation and go to run. Rather the key goes to "ACC" when I turn it back counter clockwise after one second of engine cranking.

I do know that the primary filter (the one under the coach) is full of fuel. I do know that the secondary (one the engine) has no fuel. I looked inside the one on the engine and drained some off the one under the coach. This is after trying to start the engine multiple times. My method has been to crank the engine for 5 to 10 seconds and then wait until the starter cools and try it again. I am now on the end of day two after about 12 attempts. This would be more than enough time for the fuel pump to refill the system.

When I completed the filter changes it started immediately and ran for 5 or 10 seconds. I have also had it running for 5 or 10 seconds twice since.

I see that the check engine icon is on. This is the one at 12 oclock on the dashboard and looks like an engine. However, the manual says that this indicates a minor problem of some kind and should not make the truck undriveable. I can not recall if this check engine light is normally on until the engine starts?

Does the one filter being full of fuel prove that the fuel pump in the fuel tank is working? If so would not that pump be strong enough to push whatever air might be in the line between it and the secondary filter mounted about 10 feet away? Or is the filter under the coach gravity fed?

I have tried filling the secondary filter housing from a bottle. It does draw down a few ounces when I crank the engine for about 40 seconds (four 10 second sessions spaced hours apart)

I can hear an escape, or influx, of pressurized air when I open the drain valve on the engine mounted filter. Which again makes me wonder if the pump is not infact attempting to fill both filters. Or it could be the high pressure pump attempt to suck fuel from the empty on engine filter. Either way something seem blocked?

I have loosened two of the injectors on the engine and found some fuel. But did I had no helper so I was only able to place a tiny piece of paper towel to absorb any flow and prove fuel was present. Since I did not witness this, thus I do not know if it was new bubbling pressurized fuel, or old fuel that may have been sitting in the lines. I was more hoping to release some air and hope for fuel to fill the void than assuming that the high pressure pump was not working.

In fact my assumptions are that the fuel pumps are most likely working as it all worked fine before I changed the filters.

Tomorrow, I might get brave and disconnect the fuel line after the primary filter under the coach and see it fuel pumps out of that line. If it does pump, then there must be either some blockage (air?) in the line between the two filters. Or perhaps some blockage in or after the secondary filter. Though again, people do run out of fuel. So what the heck?

These are OEM filters. I did read that off spec filters and no filters will cause the engine not to run. I could purchase two new filters and assume that I got a bad filter? I could put the old ones back in as a test but don't like the idea of putting used filters in even for a test. It would be interesting to know how the engine fails to run if it does not accept the filters. Does it shut off the fuel pump in the fuel tank? Does it turn on the check engine light?

Again, it did start twice briefly in addition to immediately after the filter change. Thus I am thinking it is not a wire I knocked loose though I am reviewing that also.

Anybody got any more ideas?

[caseymyers]

Originally Posted by daveinthekeys

I changed both primary and secondary filters. First, I did the one on the engine, and then the one under the coach. Doing these at the same time presumably drained all the fuel from the lines? I noticed quite a bit of fuel drain after the under the coach filter, closest to the fuel tanks, was removed. I am wondering if I should have done them sequentially and that way started the engine between filter changes? On the other hand, people do run out of fuel on the highway. So this would be solvable.

The owners manual says, if you run out of fuel, "Turn ignition switch to the start position to engage starter for one second, return ignition switch to run position. This will activate in tank fuel pump for approximately 15 seconds. Repeat this process twice."

My key does not work that way. I can not turn off the starting operation and go to run. Rather the key goes to "ACC" when I turn it back counter clockwise after one second of engine cranking.

I do know that the primary filter (the one under the coach) is full of fuel. I do know that the secondary (one the engine) has no fuel. I looked inside the one on the engine and drained some off the one under the coach. This is after trying to start the engine multiple times. My method has been to crank the engine for 5 to 10 seconds and then wait until the starter cools and try it again. I am now on the end of day two after about 12 attempts. This would be more than enough time for the fuel pump to refill the system.

When I completed the filter changes it started immediately and ran for 5 or 10 seconds. I have also had it running for 5 or 10 seconds twice since.

I see that the check engine icon is on. This is the one at 12 oclock on the dashboard and looks like an engine. However, the manual says that this indicates a minor problem of some kind and should not make the truck undriveable. I can not recall if this check engine light is normally on until the engine starts?

Does the one filter being full of fuel prove that the fuel pump in the fuel tank is working? If so would not that pump be strong enough to push whatever air might be in the line between it and the secondary filter mounted about 10 feet away? Or is the filter under the coach gravity fed?

I have tried filling the secondary filter housing from a bottle. It does draw down a few ounces when I crank the engine for about 40 seconds (four 10 second sessions spaced hours apart)

I can hear an escape, or influx, of pressurized air when I open the drain valve on the engine mounted filter. Which again makes me wonder if the pump is not infact attempting to fill both filters. Or it could be the high pressure pump attempt to suck fuel from the empty on engine filter. Either way something seem blocked?

I have loosened two of the injectors on the engine and found some fuel. But did I had no helper so I was only able to place a tiny piece of paper towel to absorb any flow and prove fuel was present. Since I did not witness this, thus I do not know if it was new bubbling pressurized fuel, or old fuel that may have been sitting in the lines. I was more hoping to release some air and hope for fuel to fill the void than assuming that the high pressure pump was not working.

In fact my assumptions are that the fuel pumps are most likely working as it all worked fine before I changed the filters.

Tomorrow, I might get brave and disconnect the fuel line after the primary filter under the coach and see it fuel pumps out of that line. If it does pump, then there must be either some blockage (air?) in the line between the two filters. Or perhaps some blockage in or after the secondary filter. Though again, people do run out of fuel. So what the heck?

These are OEM filters. I did read that off spec filters and no filters will cause the engine not to run. I could purchase two new filters and assume that I got a bad filter? I could put the old ones back in as a test but don't like the idea of putting used filters in even for a test. It would be interesting to know how the engine fails to run if it does not accept the filters. Does it shut off the fuel pump in the fuel tank? Does it turn on the check engine light?

Again, it did start twice briefly in addition to immediately after the filter change. Thus I am thinking it is not a wire I knocked loose though I am reviewing that also.

Anybody got any more ideas?

I have a 3500 RAM and my limited knowledge is that you have to 'prime' the filters. They have to be full of fuel when you put them back together. Other wise the engine will not get fuel. Hope this helps.

[Ida Ratherbe Camping]

I think your air locked, I would loosen cap on filter at engine turn key to run position and let fuel pump push the air out of the canister. That's what I would try

[chaps2018]

Originally Posted by Ida Ratherbe Camping

I think your air locked, I would loosen cap on filter at engine turn key to run position and let fuel pump push the air out of the canister. That's what I would try

X2. Just turn the key on and let the fuel pump run until it starts squirting fuel out the engine-mounted filter fuel petcock. Close it then prime once more and start.

Just checking, u did reconnect the cable on the chassis mounted filter. (Re:error light)

I don't recall seeing a sequencing requirement.

Keep us posted

[halla]

Might be similar to the Freightliner. I had an issue after I changed the filters. I did not prime them properly, it wouldnt start and after it did, i had a lot of air in the lines, kept shutting down.

[Orangecrush]

Originally Posted by halla

Might be similar to the Freightliner. I had an issue after I changed the filters. I did not prime them properly, it wouldnt start and after it did, i had a lot of air in the lines, kept shutting down.

Having said that, would you suggest changing one, starting it up and then changing the other?

Mark

[caseymyers]

There is a specific procedure in the manual, all I remember is that the one on top has to be totally full when you screw it back on or the air in the system will cause you all kinds of fits.

[caseymyers]

http://www.trucktrend.com/how-to/eng...filter-basics/

[Orangecrush]

Originally Posted by caseymyers

There is a specific procedure in the manual, all I remember is that the one on top has to be totally full when you screw it back on or the air in the system will cause you all kinds of fits.

Not that I'm not mechanically not able to do this but those "fits" is why I'll just let the dealer do it. (Did I just use a double negative? LOL)

It's those times that a job that would normally take 45 minutes takes 3-4 hours because I'm chasing down something I did wrong. Not worth my time...


Mark

[halla]

The local dealer told me to fill both filters as high as possible with fresh diesel. Then follow the procedure in the manual.

[B and B]

Worse case is call a mobile mechanic to check not over if bleeding air doesn't work.

[caseymyers]

That's it Halla, both full and then there is a cranking sequence to keep or get the air out. What I've done is buy the filters at Cummins (cheaper than the RAM dealer) and then bring my own filters to the service tech. Used to do that on my big diesel pusher too.

[Brewhedd]

I wouldn't be disconnecting fuel lines and injectors. I don't get how you can't crank the engine for a second and then return the key to the "on" position. Every vehicle I've ever owned will allow you to do this. The problem is all the air needs to be bled out of the fuel system. Personally, I decided when I bought my new Duramax that I wasn't going to do something even as simple as changing the oil. These motors are just too expensive and I don't want a warranty claim denied if something happens. The dealer will be changing the fuel filter also. I don't want a problem, like the dealer claiming the fuel system was damaged when I changed the filter. Just not worth it over a hundred or so bucks.

[daveinthekeys]

Ok, I was wrong. The on-chassis fuel filter is not filling with fuel. It was full because I filled the on-engine filter and it drained back to fill the primary under the truck filter. I can fill and drain the under the truck filter from the front on engine filter easily. I thought the full primary filter proved the pump was working. But I was wrong.

I now know for a fact that the fuel pump in the tank is not filling the primary filter. I have made several engine cranks of 10 seconds each and there is zero fuel in that under truck filter. Thus, my earlier assumptions about the pump filling the first but not the second was incorrect. And I lost two days from this bad assumption.

I will say that the idea of loosening the forward filter cap and/or opening the drain valve was the pathway to this discovery. So thank you for those ideas.

Now, I have to wonder why changing filters would cause the fuel pump not to run. The idea that the pump decided to go bad at exactly this point with 14,800 miles seems unlikely.

I had a neighbor turn on the key and also crank the engine while I was next to the fuel tank. And I did not hear any pump running. I could not feel any pump action on the side to the fuel tank either. I assume that I should have.

Next I am going to attempt to discover where the pump relay is and see if I can find a way to jump it. Though this seems like a strange time for a relay to go bad as well.

Sadly, as far as service help goes, I am located in the Central Florida Keys. We lost a lot of talent and resources in the hurricane. I do have a NAPA store and perhaps a mobile mechanic from somewhere closer than Miami (two hours away).

If I can not solve this today (Sunday). Then it is time to ask for help. If it exists.

I have no idea if this would make a difference. But I am wondering about removing the positive battery cables from both batteries and wondering if this might reset something. Perhaps some sort of ECU command of no fuel has shut off the pump? Ok wishful thinking.

[daveinthekeys]

I tried the battery disconnect but that did nothing. I was hoping it was some sort of error code that might reset.

I removed and reinstalled both filters and filled with fuel. But it does not start.

Note that the pump does not move any fuel. I am certain that the pump is not pumping, or at least it is not filling the under chassis filter, which after it was filled would allow for the on engine filter to be filled.

This electric pump should be able to prime the system after several key cycles. But the fuel filters do not get any fuel. Thus the electric fuel pump does not prime the system as it should.

There are no Ram dealers within two hours of me. Not to mention they generally don't work on motorhomes.

The nearest Dynamax RV dealer is 4.5 hours away. There is an unbranded general RV place one hour away. But they are more interested in the RV components than the chassis engine/drivetrain.

I find it difficult to believe that the pump has failed. This is a simple filter change that anybody should be able to do. I have done many diesel filters, and primed many systems over the years in boats and trucks. This is the first time for this truck however. The electric pump should fill the canisters with the key cycles. If the filters were getting fuel. And the engine would not start. I would assume some air was locked in the injectors and priming would be the next step. However I have read that the electric pump should make priming of these modern diesels unnecessary?

In any case with no fuel being pumped to the filters. I am thinking that primed or not is not the issue.

I guess it is time to disconnect the wires to the pump and see if they are getting power. That is if I cannot locate the relay first as it would have to be easier to get to.

I would be happy to hire this done. But I live in the middle of The Florida Keys. Finding help is not easy.

[daveinthekeys]

Some Current Ram diesels, including mine, have "TIP" start.

We turn the key to the crank position then let it go and the engine will continue to crank over until it starts, or until you turn off the key.

Without Tipstart, you would have to hold the key in the crank position until it started then let it go.

[Whalenss]

Watching this thread as I will change fuel filters when time. I know from experience on other diesel vehicles I own that any air in the line will prevent the vehicle from starting.

There are multiple videos on YouTube showing how to do this.

Referencing a couple key points from the manual. Do not pre-fill the filters. NFNR ( no filter no run ) feature. Did you use OEM filters? Says engine will not run with inferior/ non-approved filters.

Per what folks have posted on YouTube, cycle the key 4-9 times ( not starting ) to prime the system.

I agree that it is not likely a fuel pump problem. Check the fuel pump fuses.

If I were having this problem I would
- remove the filters, drain and reinstall. Cycle key on for 15 secs then off for 5 times then try to start.
If it still will not start and you didn’t use OEM filters I would replace with OEM filters.

Good luck.
Pat

[daveinthekeys]

I did use OEM filters. And against my better judgement reinstalled the old filters as a test hoping to find that I bought a bad filter. Also, I did check the fuse #70 and determined that it works. I also used a voltmeter at the fuse to show that it is energized when the key is turned on for about four seconds. It also remains energized for as long as the engine is cranking.

I have not found the pump relay yet (assuming it has one). I can not get to the wiring of the pump itself which is on top of the fuel tank. Though I find it difficult to believe that the relay or pump has failed exactly at the moment when the filters where changed. But sending power directly to the pump would be a nice test.

I have both filled and not filled the canisters of the filters. The directions say not to fill them as they are worried about introducing contamination. However, while getting desperate have tried it both ways.

Currently I have the new filters reinstalled and they are full of fuel that I manually put in there. Strangely it once again started for about 15 seconds today. Which is the third time this has happened after a dozen or so attempts each day, over three days. That is one mystery start each day.

I think there maybe a way for the fuel to leave the on-engine filter and move to the injectors based on suction from the high pressure pump? However, I am just guessing here. And it of course only happens when I have manually filled the filter canisters. This time when it ran the cover was loose on the on-engine filter and no fuel spilled/pumped out. It should have if the main fuel pump was working.

I know for a fact that the pump is not moving fuel to the filters. I have cycled the key numerous times and then looked into the filter canisters and found them empty. I both cycled the key without turning over the engine and with turning over the engine many times.

I can not hear any pump running, or feel anything vibrating inside the fuel tank. I assume I would both hear and feel the pump's action.

One idea that I am unable to test is that the new filters were somehow inferior and that the do not run function has been enabled. I wish I knew if that function was to shut off the main fuel pump (after about 4 seconds). And while I did reinstall the old filters. It is conceivable that they are now also out of spec as seen by the sensor on the filter housing (assuming such a thing exists).

Monday my one source for parts, the local NAPA store, probably has these filters in stock. I intend to purchase new ones and start over.

I wish I knew how to be positive that the main fuel pump was, or was not working. I assume that I would hear it/feel it. But I never noticed it when it was working either. Though I have gotten next to the tank and had a friend turn the key and heard and felt nothing.

[jtesta1]

Pull the filters off and fill them with fuel then reinstall. If it still doesn't start your pump is air locked and needs to be primed. We use to hit the air intake with a good starting fluid with an upper cylinder lubricant only a small amount. To much will cause a hydraulic lock or possible run away.

[Jdb95661]

Did you put some fuel in the filters before you put them in.