New Injector knock/ping, 3rd set!

[Stanley]

First set of new injectors from dap, had to send back for warranty, put 2nd set in then had to do the same thing again. With this being the 3rd set am I just having really bad luck with injectors or is something else causing it? 

I keep getting a knock/ping and sounds like a bad miss if u (more prominently)coast and very lightly tap or ride the throttle and just runs rough/ just not how it should. Runs rough and knocks when normal driving the same just more so as stated above.

Why do I keep getting this knock etc? Is the vp44 causing this to go down stream? Fuel psi is consistently 16psi, no codes or check engine light (doesn't mean awhole lot but..) 

This has all been in a very very short period of time. The last thing added was the quadzilla adrenaline but I don't see it being any issue? 

 

Only things I can think of is 1- injection pump (runs great) 2- injector lines or tube (mating surfaces looked good) 3- just getting bad injectors. 

 

What the heck?

Edited November 10, 2021 by Stanley

[Dieselfuture]

I doubt 3 sets are bad, timing maybe

When the engine is running loosen injection lines one at a time to see if knock goes away

[Stanley]

That's what I did with the other 2 sets. I didn't have time tonight to crack this set but tomorrow or Thursday probably. Both previous sets everything cleared up when I cracked the problem injector, also swapped injector holes to see if it followed which it did. So I guess we'll see what happens  cracking these. 

I set my iquad back down to 0 to check but there wasn't a change, thinking about timing and all...

[Dieselfuture]

Well if it changes and followed, I hate to say it but it points to injectors. Not sure what's going on there. Did dap say anything on previous 2 sets, did they find a problem with whatever injector and cause?

[Stanley]

Third set I haven't sent in, waiting on their return slip. They didn't mention what the problem was but the 1st set was rebuilt and sent back to be the 2nd set. The 3rd and current set, Mitchell said was new. Idk what to do. I'd like to figure out if it is possibly something else before I call dap again with bad news. I don't want it to be something else but...

 

So here's those pics/tune. Pretty much exactly what everyone on here has suggested to use or try. 

I still think I need more fuel so I might add +2 to everything and see what happens. I'll prolly post this in my other thread too. 

 

[Stanley]

I had a better longer clip 97mb but wouldn't upload -sever error. Not the best example and not the best sound quality but it's something. Prolly have to turn up volume.

 

 

Edited November 10, 2021 by Stanley

[Dieselfuture]

9 hours ago, Stanley said:

I still think I need more fuel so I might add +2 to everything and see what happens

Are you talking in the beginning or towards the end. 

With my 7x10s and 62x67x12 my fuel starts at 76 it's at 100 by 10 psi. Maybe try starting at 80 and ramp up by 3 till 10 psi then ramp by 4 till the end just to see what happens. 

Not really sure what you want to achieve and how your turbo spools, starting at 90 do you have much smoke on take off? When is the turbo spulling up and cleaning things up? 

In the video does sound like a miss, not sure I'd do a whole lot till you sort that out with dap. 

[Silverwolf2691]

I think you might be running into the injector size issue. Dragon flows are posted for sale with a minimum of 6 x .016 injector. That's roughly a 4-500hp injector. You might be killing the injectors with the injection pump. Especially since it was 3 sets in a short amount of time. I would start leaning towards yes you have a dragon fire pump and need the injectors to match it.    

[Stanley]

3 hours ago, Dieselfuture said:

Are you talking in the beginning or towards the end. 

With my 7x10s and 62x67x12 my fuel starts at 76 it's at 100 by 10 psi. Maybe try starting at 80 and ramp up by 3 till 10 psi then ramp by 4 till the end just to see what happens. 

Not really sure what you want to achieve and how your turbo spools, starting at 90 do you have much smoke on take off? When is the turbo spulling up and cleaning things up? 

In the video does sound like a miss, not sure I'd do a whole lot till you sort that out with dap. 

Yea pretty much no smoke at all really, for what I have I figured I'd have alot of smoke to try and clean up. I guess I really don't know what I need to shoot for? And at this point prolly still don't know how to lol. 

25 minutes ago, Silverwolf2691 said:

I think you might be running into the injector size issue. Dragon flows are posted for sale with a minimum of 6 x .016 injector. That's roughly a 4-500hp injector. You might be killing the injectors with the injection pump. Especially since it was 3 sets in a short amount of time. I would start leaning towards yes you have a dragon fire pump and need the injectors to match it.    

That is very possible, the ones I sent in as cores were 6x18's verified by dap. Mitchell said that these 6x13's would work either way with dragon flow or not... so idk. I guess I'll just have to call them. I'm kinda stumped.

[Silverwolf2691]

6x13 or 7x13? 

 

Not going against DAP, but I'd go with what the manufacturer of the part specifically mentions.. 

 

For the digging I did, it seems that monster pumps, lightning pumps, and dragon flows all add some amount of timing, and they increase the pressure and flow. Specifics to the above are about as easy to find as a live hippogriff..

 

The pumps need the extra volume from the lines, connector tubes, and injectors to flow the added volume needed in the short amount of time the distributor rotor is open to that line. If the pump cant move the fuel through the injector holes fast enough, it can cause damage to the vp44 itself. Think trying to squeeze water out of a bottle with a 1/32 hole vs a 1/8 hole both are gonna have resistance but the 1/8 hole is gonna release the pressure faster and flow more per stroke.

 

I wish jlbayes was on here still. Tfaoro too. Both of them were heavy on the performance side, Jlbayes more so than tfaoro. Jlbayes might have been able to explain a bit better..

[Stanley]

They are 6x13's I was wanting to down size most I could to clean everything up and get maybe a smidgen of fuel mpg back but we can see where im at now. 

So far the only option I got is to call dap and see what they say. Maybe I'll just bump it back up to 6x16s or 

6x18s. Idk what else to do.

[Silverwolf2691]

6x16s or an equivalent 7 x XXX might be beneficial. Finer spray from the 7 holes might help with smoke and a smidge with mpgs..

 

Probably a 7x14 or 7x15.

 

Best to call dap..

 

Edit: just did some math for cross sectional area, 7x015 are just a fraction of a hair larger than 6x016s. 

 

(pi*r^2)*# of holes for total cross sectional area 

 

7 x .015 = .001236375 in^2

6 x .016 = .00120576 in^2

6 x .013 = .00079599 in^2

 

Your current injectors are about 33% smaller area wise than the minimum recommended size.

 

Edited November 10, 2021 by Silverwolf2691

[Dieselfuture]

3 hours ago, Stanley said:

Yea pretty much no smoke at all really

That doesn't sound right with the size of your injectors and I'm sure your turbo doesn't spool instantly. Idk just thinking out loud.

[Silverwolf2691]

Just mulling over @Stanley's combo on the truck.. do you have any issue spooling the turbo either before or after the injectors/quad?

 

I think his setup is slightly more efficient and can toss more fuel at it before it smokes. For the average person a cam isn't needed but if the previous owner was putting the money into the truck for sled pulling, there might have been some head work done and that is what really helps a cam shine with a Cummins is head work. The cams have been known to drop spool up time by quite a bit for larger turbos.

 

The other thing is with the higher pressures he might be getting a finer mist from the injectors making a better burn.. the other thing is his turbo is larger on all fronts so its gonna take some time to spool but it also moves some serious air, 80-90lbs/min if I remember the DAP website correctly. 

 

I mean you could start at like 115 then ramp up to see if it smokes like the old tuner...

 

all of this is just word vomit of my thoughts.. most of it is speculation

[Stanley]

Before the quad and new injectors having those 6x18s in it would take a bit to spool up then boom off like a rocker, then they started acting up to which where we are now. 

I guess if their that much smaller then a bigger pump wouldn't like that nor the injector. Since I had the truck till now I haven't got better than 12mpg 😳 I'm sure after quad gets dialed in it might get better but...

The spool with the quad is pretty decent, better than before atleast.

[Dieselfuture]

1 hour ago, Stanley said:

Since I had the truck till now I haven't got better than 12mpg 😳

 I think my old time worse was 13.5 hauling a decent load. You must  everywhere you go.

What are you setting up your truck to be used for anyway

[Stanley]

Just a fun daily driver I guess. I don't tow hardly ever maybe a handful of times a year if that. It's my daily so there's that, alot of my stuff doesn't necessarily contribute to a daily but... 

When I wanna hammer down by God I wanna hammer down haha. 

 

I removed 2* from everything

1500 @ 10, 2000 @ 15, 2500 @ 19, 3000 @ 23, max @ 27 

and 100 from 0-10 then +2 till 15 then +4 up to 30

[Silverwolf2691]

How does the truck feel?

 

Any better with 20% more fuel?

[Stanley]

5 minutes ago, Silverwolf2691 said:

How does the truck feel?

 

Any better with 20% more fuel?

I literally just got home with it. Hard to tell with 5 cylinders lol the timing change made it less peppy I think. I noticed a bit of smoke but nothing even close to pre injector/quad, I also didn't want to really push it cause who knows what could happen with this Mish mash of things going on. 

[Silverwolf2691]

Smoke will come with wire tap trust me lol. Lets get injectors figured out first then go from there