Extended cranking, fuel system tests.

DEEZUZ said:

My first thought was having a shop bench the injectors. There's a reason the return test doesn't really exsist outside of the bench. We run these all day long for customers

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I never looked at the injectors that close, is it possible to get injection pressure back into the return line and blow the return lines off?

Or is it just a mater of available fuel being diverted to the return?

He said that an injector may not miss or act funny in anyway. May pass every test until you put it on a bench.

So that might still be my original problem. I got a ton of idle time on them. I need to talk myself into pulling them.

Okay, to update and share what info I can.

VCV, volume control valve, or valve on top of the pump. Seems like half these things go by different names.

Anyway, KOEO I get no noise, rattle, vibrations, buzz, anything out of it like I read I should. So don't expect that.

Did test that I have voltage to it. Didn't check more than that because I am focused on having fuel flow only. That doesn't account for the changing duty cycle required by the PCM.

To test it, it is similar to the PCV.

Set up a return line from the PCV on the left rail, KOEO command the fuel pump on, and PCV off. Or just turn the key on and it will run for 30 seconds or whatever.

Now you are supposed to command the VCV to highest duty cycle and observe flow, and then lowest duty cycle and observe flow.

I didn't get this far, because I saw flow. That is all I needed to know. But I "think" you can just unplug the VCV and flow should stop. Not sure about that.

We are talking about flow out of the return line at the Pressure control valve on the left rail.

Just for kicks I did pull the VCV apart and verified the plunger was not stuck. Seems like it would be really easy to get metal shavings in there or dirty. Not recommend unless you are desperate.

PCV testing, Pressure control valve.

So the way this works, when you turn the KOEO it is open to allow the rails to fill with fuel, During cranking it shuts the flow off so the rail pressure can rise.

If it is stuck open the rail pressure will come up slow, not rise, or rise but be too low to start.

I got the return line off finally. Clamped it off. It still leaked a little.

Ran a hose into a bucket.

Turned key on until fuel was flowing out the hose.

Cranked engine and flow stopped. PCV is good. Doing it's job.

Sorry for the crappy video. Didn't realized you can't see the fuel flow but you get the idea.

After all that it would indicate the HPFP has failed. Whether it be an inlet suction valve stuck open and allowing fuel to just recirculate, or catastrophic failure, don't know yet.

I am still going to pull the injectors and have them tested, but it looks like I am headed back to my original plan of doing pump and injectors.

From what I have read, injectors about 5 hours to do. HPFP about 6.

I have the engine half apart I can reach everything so hopefully I will get it pushed back inside and torn apart this week yet.

Hopefully it's just the pump after all the time you have put into it.

Thanks for documenting the process. It could come in handy someday.

Hope it helps someone. Been quite a journey so far. Can't believe it is so hard to find info. Consistent info.

or the typical follow ups. I hate that, no solution ever posted. Can only imagine it gets junked or sent to the dealer.

I am back and forth on just buying injectors or having these tested, but I think I will get them tested for info sake. I doubt this friend of mine will charge me. Seems like people are pretty adamant about 6.7 injectors rarely fail. I need to see how many hours my truck has and post that as well.

Seems like you can find every tiny detail about every other engine online. in many ways the 6.7 is a bit of a mystery, but then I am just getting started really.

Either that or they are just reliable, and most ppl just fix whatever problem arises instead of spending more time non-diagnosing than repairing...

sootie said:

Either that or they are just reliable, and most ppl just fix whatever problem arises instead of spending more time non-diagnosing than repairing...

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LOL true.

I always have the weirdest stuff happen to me anyway. I mean most people pull the volume control valve and find rust or metal shavings. Nope, not me.
Most people get a low fuel pressure warning. Nope not me.
Most people get an injector code. Nope not me.

Honestly should have just ignored the symptoms and kept driving it till left me sitting someplace.

Injectors are out, look better than I expected. Off they go for testing this morning.

I suppose the best I can hope for is to have 3-4 bad ones that bypass enough flow to prevent the rail pressure from climbing.

Pulled the PCV, pressure control valve as well because I was there.

Looks clean. Thought it was interesting, the end looks knurled. It isn't metal flake, nothing that will come off. Looks machined, I wonder what the intention was in doing that.

Was thinking about putting a new CCV filter on, but if it was meant to be a maintenance item then why would Ford put the IAQ numbers on there?

I was certainly blessed pulling injectors, maybe took me 2 hours. No broken hold down bolts, all the injectors popped right out. None of the horrors you read about.

Tiha said:

Was thinking about putting a new CCV filter on, but if it was meant to be a maintenance item then why would Ford put the IAQ numbers on there?

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The CCV filter lives in this weird limbo of is it or isn't it a maintenance item. Ford doesn't give an interval for the box (for certain the box one without the filter). Ford got away from the filtered design and went back to the baffled box. Either way they can still gum up/plug up and cause excessive crankcase pressure which leads to oil leaks. I heard one diesel shop was recommending changing the CCV every 50,000 miles as they were having good luck avoiding the "common" oil leak locations (turbo, main seal, upper oil pan). If you change it either write down IQAs or keep the old lid if you think you may need them later.

6.7Bison said:

The CCV filter lives in this weird limbo of is it or isn't it a maintenance item. Ford doesn't give an interval for the box (for certain the box one without the filter). Ford got away from the filtered design and went back to the baffled box. Either way they can still gum up/plug up and cause excessive crankcase pressure which leads to oil leaks. I heard one diesel shop was recommending changing the CCV every 50,000 miles as they were having good luck avoiding the "common" oil leak locations (turbo, main seal, upper oil pan). If you change it either write down IQAs or keep the old lid if you think you may need them later.

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Great info, thank you. Now I don't have to go searching for it.

I feel like I want to replace it. But then I also want to do glow plugs and valve cover gaskets and who knows what else, but really I don't need any of those things.

Slight leak on the driver's valve cover gasket. Actually wondered if a new CCV would make that go away.

Ccv filters blow the oil cap out of your hand when they're beyond service life.. You'd think there was a dead hole.. Nope. Just Ccv filter. Lol

make sure your truck actually has the filter. Ford updated it and went to a baffled box, which i have not seen personally plug up.

Okay, Injector test results.

1 failed miserably, IAQ test I think is what he called it. The computer cannot accurately control the injector.

3 more are what he called in the yellow, meaning they are not always responding accurately.

Nothing that would cause a no start condition, so I need a CP4.

He said the injector problems I have would cause smoke, soot, and run ability problems. Which hopefully will cover some of the issues I think I was having.

reusing 4 injectors, installing 4 new ones.

Now back to what CP4 to get. He is getting me prices on what they have available as far as pumps and injectors.

Now I know.

He said they usually use alliant which I think is a good name. I honestly have no idea about reman injectors anymore. Seems like everyone has some for sale.

Id still throw a lpfp on it before i started on the high pressure side.

Even if you can swap with a buddy to test. Its like a 10 min job for the lpfp..

lincolnlocker said:

Id still throw a lpfp on it before i started on the high pressure side.

Even if you can swap with a buddy to test. Its like a 10 min job for the lpfp..

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Not sure what I am going to do yet.

LPFP I have 62 psi while cranking. Hard to imagine there can be any issues there but who knows. Still trying to decide what direction to go next.

Actually thinking more about the VCV, I never got a click or a buzz or anything. Seems dead to me. But there is so little info, not sure how else to test it besides throw another on there. I think they were like $100 on ebay.

I can't do any more testing on the VCV until I get the injectors back in. So I have time.

Honestly I am thinking after all this about throwing a contamination kit in. 4 injectors and a CP4 would probably cost me $2200. $1700 if I go the cheapest route. I have the other 4 injectors, how great can they be. I have 2 questionable connectors on my return line. I would need install kits if I re use those 4 injectors.

If a whole kit is $4k or even less online at some places, then what am I saving? I think I saw one kit listed at $2999. Even if they are not the greatest they have to be in better shape than what I have now for a truck I probably won't put another 100k on.
Just sucks that even after I try so hard to do a proper diagnosis that here I am thinking about a whole kit anyway.

Tiha said:

Not sure what I am going to do yet.

LPFP I have 62 psi while cranking. Hard to imagine there can be any issues there but who knows. Still trying to decide what direction to go next.

Actually thinking more about the VCV, I never got a click or a buzz or anything. Seems dead to me. But there is so little info, not sure how else to test it besides throw another on there. I think they were like $100 on ebay.

I can't do any more testing on the VCV until I get the injectors back in. So I have time.

Honestly I am thinking after all this about throwing a contamination kit in. 4 injectors and a CP4 would probably cost me $2200. $1700 if I go the cheapest route. I have the other 4 injectors, how great can they be. I have 2 questionable connectors on my return line. I would need install kits if I re use those 4 injectors.

If a whole kit is $4k or even less online at some places, then what am I saving? I think I saw one kit listed at $2999. Even if they are not the greatest they have to be in better shape than what I have now for a truck I probably won't put another 100k on.
Just sucks that even after I try so hard to do a proper diagnosis that here I am thinking about a whole kit anyway.

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Before you spend anything more. Try the lpfp when you get it back together. Even if you have to con someone to barrow one.

what are all the codes that its throwing?

lincolnlocker said:

Before you spend anything more. Try the lpfp when you get it back together. Even if you have to con someone to barrow one.

what are all the codes that its throwing?

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It has never thrown any codes until no start condition. It is low rail pressure while cranking. That is the only code that comes up.

I am kind of at the point, am I going to waste time buying 4 injectors? Or put the failed used ones back in to do more testing? Seems kind of silly.

But even more stupid, the package price for a contamination kit is cheaper than the components. So I go and buy new injectors and still need a pump later?

4 reman bosch injectors with fuel lines is $1800. 8 would be $3600. Then a pump would be another $1000. There are a few bosch contamination kits for less than that. Even his shop was cheaper as a kit.

I think I am kind of backed into a corner at this point.

Tiha said:

Just sucks that even after I try so hard to do a proper diagnosis that here I am thinking about a whole kit anyway.

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This seems to be the way of the world anymore. More and more its cheaper and easier to just throw parts kits at the problem or throw away and buy a new one. Time is more and more precious to me so I do end up doing more "What else should I replace preemptively while I am in this deep? I don't want to tear it this far apart again for a while." Can't say I think this is a change for the better as a whole but it's what we are working with.

Personally if half your injectors are no good I would assume the others may be headed the same way unless all 4 bad ones came off the same rail, then maybe double check the rail and associated lines to make sure that's not an issue. I would at lean towards getting all 8 injectors and lines. I don't think it's common for the injectors to wear out (can't remember how many miles you have on it). Usually it's more of a contamination issue. Just make sure everything is spotless.

I don't have any more knowledge than you on the fuel system so the only other thing I can do is encourage you to keep digging. The problem is there somewhere.

6.7Bison said:

Personally if half your injectors are no good I would assume the others may be headed the same way unless all 4 bad ones came off the same rail, then maybe double check the rail and associated lines to make sure that's not an issue. I would at lean towards getting all 8 injectors and lines. I don't think it's common for the injectors to wear out (can't remember how many miles you have on it).

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I agree, doesn't make sense to just put 4 injectors in.

as far as those bad injectors causing a no start. That is not the case, it is the reason I took them to a shop with a high dollar test stand. If they were bypassing flow the test stand would show it.
The test I did running the return lines into cups was worthless. Even though the vehicle would run, idle fine.
Maybe if there was a bad injector return flow it would have shown up the way I tested it. But it didn't and the high dollar test stand verified that they were not bypassing fuel.

But still they are not in great shape otherwise 4 wouldn't be bad. Only 187k miles but I think it has a ton of hours on it.

This is just a spare vehicle for me. I love the truck but I don't need it. It was my old company pickup I was able to buy super cheap. That is why I decided to spend so much time diagnosing. No hurry. Couple hours here and there when I feel like it.

It seems absolutely ridiculous to me, I originally thought I would find metal shavings on the VCV, once that showed clean then it seemed preposterous to buy a contamination kit. I just needed to trouble shoot more. Now I am right back to, it is cheaper to buy the whole kit.

It is pushed out of the way for now. I need to do some other projects, but I think I am going to buy a decent contamination kit. I will get the injectors in. Then maybe I will play with it some more before I install the new fuel pump.

But at this point I can't do any more testing until I get injectors in it.