LML LML fuel sys info:
- Thread starter McRat
- Start date
Why is everyone all drooling over this LML setup and thinks its so cool? Its not anything special. The pump sucks, it flows maybe only 75% of what an LB7/LLY CP3.3 flows.
The LML's have been out for almost a year, why do you think no one has gotten one to actually go fast??
The LML's have been out for almost a year, why do you think no one has gotten one to actually go fast??
Why is everyone all drooling over this LML setup and thinks its so cool? Its not anything special. The pump sucks, it flows maybe only 75% of what an LB7/LLY CP3.3 flows.
The LML's have been out for almost a year, why do you think no one has gotten one to actually go fast??
its not really drooling that im doing, more interested in why GM did things the way they did. its a new system and i love to learn about new stuff that has come out on the dmaxes. i was always that kid that asked "Why" waaaaaaaay too much
. When ever you make it to the west coast ben, i owe you a dinner just so i can pick the heck out of your brain :hug:The return side pressure is not for the hydrocarbon injector that burns the dpf. The hci is fed from the cp3 directly from in between the supply and pressure sides of the pump. The return line pressure is just for proper injector operation.
The cp3 is now a timed unit, it has to be installed matching marks on the gears. This was never the case with any dmax pump to date. It is a two chamber unit supposedly to have more evenly matched fuel pressure in the rails.
The fuel rail pressure sensor is now in the back of the driver rail, there is 2 regulators like Pat said, there is a fuel supply side pressure sensor also. It monitors the supply pressure to monitor vacuum of the supply system. It is used as a driver warning to alert of fuel filter clogging. It is normally closed and opens if vacuum gets to 13" hg. The ecm then alerts the ipc iirc.
The cp3 is now a timed unit, it has to be installed matching marks on the gears. This was never the case with any dmax pump to date. It is a two chamber unit supposedly to have more evenly matched fuel pressure in the rails.
The fuel rail pressure sensor is now in the back of the driver rail, there is 2 regulators like Pat said, there is a fuel supply side pressure sensor also. It monitors the supply pressure to monitor vacuum of the supply system. It is used as a driver warning to alert of fuel filter clogging. It is normally closed and opens if vacuum gets to 13" hg. The ecm then alerts the ipc iirc.
ahh yes you're right, I was wrong!! What I was thinking of (and what threw me off), was that on the feed line to the 9th injector is connected to the return line through a check valve, which apparently (if the truck is run out of fuel) allows the low pressure fuel that feeds the 9th injector to "backfill" into the "main injector" return line circuit to build the required ~150psi in the return line circuit. I read the LML fuel system description a long time ago and got mixed up.
Just to be clear though, the 9th injector is NOT a high pressure injector like the main injectors. It is fed off of the low pressure side of the pump.
Just to be clear though, the 9th injector is NOT a high pressure injector like the main injectors. It is fed off of the low pressure side of the pump.
Only thing I have to add on this subject is that from a fuel supply stand point you can supply the engine with 15-20 psi of pressure without any adverse affects :thumb:.
Why is everyone all drooling over this LML setup and thinks its so cool? Its not anything special. The pump sucks, it flows maybe only 75% of what an LB7/LLY CP3.3 flows.
The LML's have been out for almost a year, why do you think no one has gotten one to actually go fast??
Not drooling, just thought all the changes to the fuel sys were interesting.
The 2 GM docs conflict. One says it's held open at 250v/20a, the other says it's fired at 160-240v/20a, then held open with 12v. I'm going to go with the second story, since there is no way there could be that much power going through the injectors, just based on how much heat would have be dissipated.
I still don't get the 20 amps though. It's a huge amount of power even if just for a short burst. Maybe they mean the ECM requires 20 amps?
ahh yes you're right, I was wrong!! What I was thinking of (and what threw me off), was that on the feed line to the 9th injector is connected to the return line through a check valve, which apparently (if the truck is run out of fuel) allows the low pressure fuel that feeds the 9th injector to "backfill" into the "main injector" return line circuit to build the required ~150psi in the return line circuit. I read the LML fuel system description a long time ago and got mixed up.
Just to be clear though, the 9th injector is NOT a high pressure injector like the main injectors. It is fed off of the low pressure side of the pump.
I did not know this. Thats a good bunch of info. And yes your correct on the hci. It is nothing more than a impala fuel injector from bosch.
The Piezo, once charged, does not flow much, if any current.
Probably an inductor ala ignition coil type setup. Not a cap.
I think I remember reading in SI that the ECM had an internal capacitor bank...ill double check on that though
Does anyone know what the pressure/voltage curve is for the LML rail pressure sensors? I ordered one and ran it on our test bench, but we could only get a stable reading up to 15,000 psi (due to the tester), but the curve appears to be 2200 bar (versus 2000 bar on the LBZ/LMM).