6-hole injectors on LMM's??

[McRat]

Pat what do you do about the voltage differences? LLY injectors require 48 vdc.

I haven't measured voltages yet. Do you know the voltages (measured) on the different engines? I don't trust GM docs, I need to see them.

I keep meaning to do it, but it's on my "list of things to do" which is getting too long.

Most likely a higher voltage will work if it's not too high. Might need a resistor to cut back on current?

 

[duratothemax]

I haven't measured voltages yet. Do you know the voltages (measured) on the different engines? I don't trust GM docs, I need to see them.

I keep meaning to do it, but it's on my "list of things to do" which is getting too long.

Most likely a higher voltage will work if it's not too high. Might need a resistor to cut back on current?

LB7 is 96vdc. LLY is 48vdc. LBZ is 12vdc (im 99% sure its 12 volts). Theres no huge heat sink or external means of cooling the LBZ ECM, so the voltage cant possibly be stepped up much higher than 12 volts.

I would be willing to bet a lot of money an LLY injector wont work with an LBZ ECM in any way shape or form. Resistor wont do anything because the LBZ ECM puts out a lower voltage than the LLY injectors require, not a higher voltage.

ben

 

[McRat]

LB7 is 96vdc. LLY is 48vdc. LBZ is 12vdc (im 99% sure its 12 volts). Theres no huge heat sink or external means of cooling the LBZ ECM, so the voltage cant possibly be stepped up much higher than 12 volts.

I would be willing to bet a lot of money an LLY injector wont work with an LBZ ECM in any way shape or form. Resistor wont do anything because the LBZ ECM puts out a lower voltage than the LLY injectors require, not a higher voltage.

ben

Sounds like too much hassle. A power transistor that is fed 48v could perhaps activate the injector with a 12v signal from the LBZ ECM?

 

[Kat]

Moved to hard parts :hello:

 

[LBZrcks]

I wonder the same but if in fact our injectors are made diffrentley or fire diffrentley how would we do this any ideas any one ?

With EFI you can adjust the number of injection events that happen

 

[Diesel power]

By theory less holes means it will hold higher rail pressure under load, thus allowing for more duration....or maybe timing?

 

[Fingers]

Fewer holes increases the gap between the fuel plumes. The fuel burns from the edge of the plume, so this might increase the surface area if the 7 holes plumes were touching.

You would have to run a higher pressure with 6 hole than 7 to get the same flow rate. That is, assuming they are the same hole size. There is no mention of the hole size, or angle for that matter.

I know of one person that was running LLY injectors directly fom an LLY ECM without the FICM. How well, or any other details, I am not privy to. In theory piezos trip on voltages as low as ~3Volts, but it depends a lot on what crystal is being used. The amplitude of the motion needed to open the injector would probably be the critical value and within bounds is what dictates the voltage needed.

But,,,what do I know.

 

[JoshH]

In theory piezos trip on voltages as low as ~3Volts, but it depends a lot on what crystal is being used.

I didn't think our injectors used piezo crystals?

 

[Fingers]

I didn't think our injectors used piezo crystals?

Stacked Piezo wafers IIRC.

It is not a coil if that is what you were thinking. Coils do not respond quickly enough with the force required.

 

[JoshH]

Stacked Piezo wafers IIRC.

It is not a coil if that is what you were thinking. Coils do not respond quickly enough with the force required.

I wasn't sure what it was, but I remember when the 6.4 PowerStroke came out there was a big deal about them being piezo injectors. I seemed to remember reading that our trucks didn't have the same type injectors as the 6.4, but they were coming in the next version. I guess I either read bad info, or the 6.4 injectors are somehow slightly different piezo setup than ours.

Thanks for the info.

 

[nwpadmax]

Stacked Piezo wafers IIRC.

It is not a coil if that is what you were thinking. Coils do not respond quickly enough with the force required.

John, I'm dang sure the LB7 and LLYs are solenoids, not piezo. I don't think the LBZ is piezo either. Ford was touting for a while that the ('08?) 6.4TT was the first in the field with piezos. The new 4.5 Dmax is touting piezos for 2010....but I can't find anything connecting piezo and Dmax (via Google) except on the 4.5.

I have a gutted LB7 injector in the shop and it's a solenoid fo sho.

 

[Fingers]

The pictures I have seen looked like wafer stacks, not coil. I'll have to cut one open I guess.

 

[Ben46a]

The injectors out of my burnt LLY engine were solenoids as well.

 

[LBZrcks]

So does anyone know if one could just change the nozzels from a LBZ injector onto a LMM injector?

 

[Dzlnut]

On the Ford 7.3L PSD guys are doing the injector driver module mod which involves changing a resister to raise the voltage going to the inj. Would this be possible with a DMax??? It is worth 20 or so hp on a 7.3 which would equal 100 to us LOL

 

[McRat]

I dunno. We are common rail, so the injector either gets enough juice or it doesn't open. Increasing the voltage might make it open faster, hence increasing effective duration.

 

[Gmclbz]

I dunno. We are common rail, so the injector either gets enough juice or it doesn't open. Increasing the voltage might make it open faster, hence increasing effective duration.

What effect would the extra voltage have on the injector?

 

[McRat]

As far as I know, it will open faster. It's travel and closing time is dependent on fuel pressure, not voltage from what I can tell. Fuel pressure holds it closed if I'm looking at it correctly.

 

[Gmclbz]

So if this would work it would make for a very efficient injection cycle then...?

 

[Dzlnut]

I dunno. We are common rail, so the injector either gets enough juice or it doesn't open. Increasing the voltage might make it open faster, hence increasing effective duration.

Pat that is the reason they do it, the voltage increase makes them function faster.