Is this the log of a dying CP3?

[SSchmi5519]

As some of you know, in order to cure my old rail issues (3000us drop to 16k rail), I installed a dual fueler setup. Granted it is much better, but I am still not achieving full rail pressure and wanted to get some input before I go buy two new CP3s.

Default log setup: yellow is pulse, purple is desired, green is actual.

Those low points are about 23,800psi.

The high points are about 25,700psi.

I'm running two LBZ regs, on stock LLY pumps.

 

[SSchmi5519]

Anyone have some insight? CP3's are dang expensive

 

[hondarider552]

I have 2 more pumps at the house if you want those :happy2:

 

[SSchmi5519]

I have 2 more pumps at the house if you want those :happy2:

See i just dont know if i wanna dump more money into used pumps :/

 

[Burn Down]

Steve are you sure the injectors are healthy? The reason I ask is I fought a similar issue a few years back on anything above 2900... Turns out I had 2 bad tips, POS kerma tdi. Anyway the balance rates were fine but the return rates were way out of spec on 2 injectors. Swapped my stock tips back on those 2 and rail was perfect after that.

 

[Chevy1925]

Steve are you sure the injectors are healthy? The reason I ask is I fought a similar issue a few years back on anything above 2900... Turns out I had 2 bad tips, POS kerma tdi. Anyway the balance rates were fine but the return rates were way out of spec on 2 injectors. Swapped my stock tips back on those 2 and rail was perfect after that.

x2, id check your return rates on those injectors first as well as the return rate out of the CP3s

 

[SSchmi5519]

I dont have a diesel fuel quality tester to get the specific gravity of my fuel

 

[SSchmi5519]

Or are you saying that if I have certain injectors that are grossly returning fuel they will show more than a ~2ml difference in fuel return during a cranking fuel return test? I need to find a place i can get 4 10ml or 20ml plastic graduated cylinders.

 

[Chevy1925]

We are sayin you may have some grossly returning injectors.

eBay has some kits for cheap iirc. If not, Amazon it ya hermit lol

 

[SSchmi5519]

We are sayin you may have some grossly returning injectors.

eBay has some kits for cheap iirc. If not, Amazon it ya hermit lol

You know i cant wait for sh.t!!! Gotta have my thangs nowww :rofl:

I think staples sells them for teachers. I just need one as ill test them individually then pour the fuel into the cyl and note the volumes.

EDIT: I'm fairly certain I will be able to notice the difference between injectors, as im sure not all are bad with only 120k. What I worry about is measuring the CP3s, since I know my valley pump is weak, and if the used one i bought for the dual is also crap I wont know exactly how far out they are.

 

[Chevy1925]

Just start with the injectors first. There is a GM spec for those. There is no spec for the the return on cp3s though unless something has changed in the last year

 

[SSchmi5519]

Just start with the injectors first. There is a GM spec for those. There is no spec for the the return on cp3s though unless something has changed in the last year

I know there is a spec for the injectors, but it changes depending on the API of the fuel. IIRC it ranges from 2ml to 5ml over 15sec of cranking depending on API, which i have no way of testing.

So my injectors could be just fine, or returning over 2x what they should and i wouldn't know the difference.

 

[Burn Down]

When I did the test I had 2 injectors returning +30ml... It was very noticeable.

 

[SSchmi5519]

When I did the test I had 2 injectors returning +30ml... It was very noticeable.

Thats what I'm hoping for, rather have a blatant issue than something vague.

 

[Burn Down]

Thats what I'm hoping for, rather have a blatant issue than something vague.

Also, Empire has a API tester. I'm sure if you took them a sample of your fuel they could test quick like for ya.

 

[SSchmi5519]

Also, Empire has a API tester. I'm sure if you took them a sample of your fuel they could test quick like for ya.

You talking Empire Diesel or Empire CAT?

 

[Burn Down]

Cat

 

[SSchmi5519]

Cat

Thanks that helps a bunch as well!

 

[Burn Down]

Thanks that helps a bunch as well!

No problem. I bet Brian knows someone there that could hook you up

 

[Chevy1925]

I know there is a spec for the injectors, but it changes depending on the API of the fuel. IIRC it ranges from 2ml to 5ml over 15sec of cranking depending on API, which i have no way of testing.



So my injectors could be just fine, or returning over 2x what they should and i wouldn't know the difference.

There ya go over thinkin again lol