Is there any credibility to this? Asphaltene

[Batman68]

(02-06-2017 )gearhead Wrote:  I think that some is bad injectors alowing compression into the fuel.

So I have a issue with the black particles getting into my fuel filter also and this only happens when my fuel gets too hot. On cooler days I have no issues at all. Do you think that a bad injector could cause this?

[Rawze]

(11-02-2017 )Batman68 Wrote:  

(02-06-2017 )gearhead Wrote:  I think that some is bad injectors alowing compression into the fuel.

So I have a issue with the black particles getting into my fuel filter also and this only happens when my fuel gets too hot. On cooler days I have no issues at all. Do you think that a bad injector could cause this?

ALL diesel engine fuel filters turn black as they clog up. Biofuel mixes are quicker to do this. Take a sample and send it to a lab. Otherwise you are just guessing.

How many miles before the filter clogs up and has to be replaced? -- What micron filter?

[Batman68]

I had some samples sent to a lab several months ago and they said that algie was negative. They did say it tested positive for asphaltene. The filters would only last about 5000 miles when the weather is hot and 3 times that long in cooler weather. I only get a engine code for “Fuel filter restriction” when fuel gets extremely hot (like 150+). When the weather gets to the upper 70’s this will happen like clockwork about 5 hours into the run. I installed a fuel cooler & a heat shield between the DPF and fuel tank to extend my run time until weather gets extremely hot (like 85 and up). Now that the weather is cooler the fuel cooler can keep up and I have no problems at all. The truck will run great! But I would like to figure this out before spring so I don’t have another summer of derating. Kenworth has the truck for 3 days and all they could say was put a new fuel pump on it. That’s the only answer they could come up with because it would never get under a load in the shop environment and they couldn’t get the code to come on, but they did notice the 50+ stored codes of fuel restrictions. I did not have fuel pump installed because I know that’s not the problem. Like I said it’s running fine now. At least til next summer. I thought that maybe a leaking injector could possibly be flash heating the return fuel and causing the heat problem. The filters aren’t turning extremely black, they just get these little black chunks in them and the paper gets soft from the hot fuel. If I let the truck cool down and restart later it runs fine again until it gets heated up and it will start to derate. I will check on the filter micron and get back. Thanks for the reply Rawze!

[Rawze]

It sounds like either your getting combustion gases into the fuel system (injector issue) or you have a check valve or other pressure relief problem that is overheating the fuel.

that is what it sounds like any ways.

what kind of enigne? milesd? - some hostory? -- is it de-mandated? if so by who?

[gatow900]

Maybe your having fuel restriction not enough fuel or getting air in the fuel. Like the vp44 pump for cummins 5.9 there lift pump was to weak to keep pressure. Diesel cools and lube the pump

[Batman68]

(11-02-2017 )Rawze Wrote:  It sounds like either your getting combustion gases into the fuel system (injector issue) or you have a check valve or other pressure relief problem that is overheating the fuel.

that is what it sounds like any ways.

what kind of enigne? milesd? - some hostory? -- is it de-mandated? if so by who?

To answer the first question from earlier today about the fuel filter microns: The water separator is 140 micron and the bigger filter is rated at 15 micron. The engine is a ISX 400ST, I also call this a ISX15. It has 837000 miles. It has not been de-mandated. Still has factory settings. When the truck went to Kenworth I discussed the pressure relief valve that regulates the fuel rail pressure with the mechanic and he agreed that could be the issue but he wasn’t sure. I ordered the part and replaced it myself. Since they had no idea what was wrong and was just wanting to start throwing parts at it I figured that if anyone was going to throw parts it would be me. I keep the tanks as full as possible so that I will have more cooling capacity. I run the truck loaded very early in the morning so that the outside temp is as cool as possible. I drive to the mill where the truck runs a pneumatic blower for approximately 2 hours of unload time. As I unload the fuel gets hotter and hotter because the engine fan can’t get enough air through the fuel cooler that I installed. After truck is empty and I start heading back home I get fuel filter restriction code and truck then derates. If the weather is cooler I can stop after a couple of hours and fuel tanks will be cooled down and check engine light shuts off an truck will run normal again. If outside temp is below 60 I never get engine light. If you think that a bad injector is causing this issue I have no problem running injector test. Just wanted to hear your feelings on the problem before I spend the $206 for the test tool. Always appreciate thoughts from the Cummins Master to help with this problem. Thanks again.

[Batman68]

(11-02-2017 )gatow900 Wrote:  Maybe your having fuel restriction not enough fuel or getting air in the fuel. Like the vp44 pump for cummins 5.9 there lift pump was to weak to keep pressure. Diesel cools and lube the pump

Thanks for the thoughts but I had the truck in the shop and they ran a pressure check and it was within tolerances. Not sure about the 5.9 but this is a ISX 15 litre. They may have similar designs.

[Rawze]

So I can only assume it is a common rail engine. you did not mention the year or the truck of model engine.

As far as the pressure relief valve or injectors go, it is as simple test. here it is...\
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[Batman68]

(11-03-2017 )Rawze Wrote:  So I can only assume it is a common rail engine. you did not mention the year or the truck of model engine.

As far as the pressure relief valve or injectors go, it is as simple test. here it is...\
\

Sorry about that. The engine is in a 2010 T660 Kenworth. No DEF. I am assuming it is a common rail system.