[roadhog350]

Hello all.... I'm having a problem with my 04 Excursion with a 6.0. First noticed a slight loss of power about a week ago that has continued to get worse. It will get so bad that it feels and sounds like it is barely firing on 2 or 3 cylinders and RPM drops to about 100. Mashing the accelerator pedal does no good most of the time but on occassions it will increase slowly to somewhat normal RPM. When you first start it up cold it will perform OK but still has low power and engine miss.

Does anyone have an idea what would cause this and is it something I could possibly fix myself?

Any help greatly appreciated.

Gary

 

[OMCUSNR]

1st thought is fuel / fuel filters. Drain your HFCM, & check for contaminated fuel. Check the fuel filters. If these are bad, you may have caused damage to the fuel pump in the HFCM, which may have damaged injectors.

After checking / replacing the filters, try to get a fuel pressure test. Hopefully one of the techs can tell you what the parameters are. I think its supposed to be above 50psi, but I don't remember.

 

[roadhog350]

I had just changed the oil, oil filter, and both fuel filters before this happened. I drained the HFCM before changing the fuel filters and there was no water in the fuel. I guess I will just have to have it towed to a dealer. I forgot to say in original post that this vehicle is 100% stock. I was hoping it would be something I could correct. Thanks for your help.

Gary

 

[teamroper60]

Considering your recent fuel filter change, my bet is that the o-ring is the culprit.... Did you change it when you did the filters?? If not, do so. If you did change it, did you lube it before you installed it??

A hole in the o-ring or a pinched o-ring will lead to very poor running, if it will run at all.... I've seen them just flat quit after a filter change that did not include changing the o-ring. Turned out, the old one got pinched when re-installing the cap. Changing the o-ring fixed the problem...

 

[Black05]

RoadHog -- I agree with TeamRoper. I'm betting that somehow air is getting into your fuel system. I would redrain the HFCM and see what you get out. If no water or other contaminents are present, then take the HFCM cover and filter back off and inspect. Check the o-ring on the cap for any tears or other abnormalities. If all appears ok, then reinstall and be sure to use lubricate the o-ring with motor oil prior to installation. Tighten the HFCM cap until it is totally flush with the housing. Activate the key three cycles, then start and see if your problem is gone. If not, repeat this procedure with the top engine mounted fuel filter. If the truck still runs poorly, then you need some diagnostic assistance from the dealer.

 

[OMCUSNR]

Yep - I agree.

 

[roadhog350]

Thanks to all for the great replys. Yes, I did change the O ring and put diesel fuel on it to lube it, but that doesn't mean I didn't pinch it on install. I will check it tomorrow and make sure the O rings are OK on both filters.

Thanks again to all for the help,

Gary

 

[roadhog350]

I just drained the HFCM and got no water but there was some kind of crud in the fuel. Another thing, the HFCM will not stop draining. After draining about 6 qts out I put the plug back in. It didn't do this the other day when I drained it and changed the filters.

I would say that I got about a 1/2 teaspoon full of crud in the 6qts I drained.

I'm going to wait until I hear back from one of you guys before I pull the filter on the HFCM because I'm afraid it will keep draining fuel.

Oh, the top filter was clean as a whistle and no crud in it at all.

Thanks for your help,

Gary

 

[Black05]

Mine has never continued to run like yours. Others here have posted that if you loosen the fuel filler neck cap to relieve pressure and park the truck nose up (or nose down, I cannot remember), then the draining will stop. I would think that if you have the top mounted fuel filter and cap installed and tight, then it should act to hold a vacuum so that the fuel will not continue to drain from the HFCM. Try these combinations and see if the draining stops. If not, IIRC the fuel filter in the HFCM depresses a check valve that allows fuel to flow. Once you loosen the filter, this check valve should close and any fuel flow should stop. Your need to get the HFCM cap off as I am betting the o-ring there is the source of your problem.

HTH.

 

[teamroper60]

I've never gotten more than a quart of fuel when draining the HFCM, so I can't really tell you why you are getting so much fuel. But if you have "crud" in your fuel, then you need to get it all out. Even if the HFCM never stops draining until the tank is empty. In fact, that might in itself be a blessing to you. That "crud" is most likely at the crux of your problem. You may well have a tank of bad fuel.. Open that drain again and let 'er rip until it either quits coming out or at least until it quits flushing junk out. Then change your HFCM filter again.

I think if it were me, I would pull the lines between the tank and the HFCM and blow them out to see what comes out of them. I would also wanna see what is coming out of the tank... If you are getting junk out of your tank, you need to know it before you ruin an injector or worse.

 

[grounder]

As far as getting all that fuel out.You just had a Siphon issue going on from the tank.Nothing to worry about.As mentioned I would seriously think about dropping the tank down and flushing it out.Obviously that crap came from there.It may be that its all just in the FICM housing but you dont know for sure.Just my opinion on the whole deal.

 

[roadhog350]

Thanks to everyone for their help. I let the HFCM drain until it stopped and got about 6.5 qts out with crud as stated before. I then re-cycled the fuel pump 3 times then drained the HFCM again. Got about the same amount of fuel out as before but less crud. I did that a third time and no more crud came out.

I then changed both the fuel filters again. Re-cycled the fuel 3 time and drained the HFCM again. No crud this time. Re-cycled again and it runs just great.

I agree that I should clean the fuel tank and lines but have a couple questions. Can the fuel tank be drained? It is full of fuel at this time. Next, does it require a special tool to remove the fuel lines?

Again, thanks to everyone for their help.

Gary

 

[OMCUSNR]

[ QUOTE ]
It is full of fuel at this time.

[/ QUOTE ]

This is most likely why it drained so much. I HAVE had it happen to me, and I now wait till the tank is 1/2 full before trying to drain the HFCM. If I'm going to change the filters, I try to put my rear wheels on a 2x to gie the frame a very slight nose down attitude. This forces any fuel left in the HFCM towards the drain hole & not out the big gapping hole the cap just came out, that will then run down the frame rail & into my face.

 

[roadhog350]

As teamroper60 said, this was a good thing in my case. It allowed me to flush the HFCM out completely. As a matter of fact, in the future I will fill the tank before I drain the HFCM so I can flush it out.

I'm not sure what fixed the problem but I think it was the O ring on one of the filters like most of you told me. I guess I should have changed them one at a time to determine which one was at fault but just went ahead and changed both at the same time.

Thank to all who responded and helped. This probably save me several hundred dollars and the loss of my X while it was at the dealer.

Gary