SRT10KLLR

iTrader: (11)

They look like the 2003(Stage 0) SRT-4 injectors that are rated 527cc(50 lbs/hr) @ 4 bar(58 PSI). I have some laying around here somewhere as I use them on F/I Hemi builds. They have a EV-6(USCAR) connector not the Multech II the trucks used to have.

XLR8NSS

iTrader: (4)

What exactly is the issue you guys are seeing? What problems is it causing? Aside from just saying they are not the greatest injector, no one has pointed out what the problem is with the IFR table. What issues pop up because of the IFR table?

I am just curious.

brantsz

The issue is only related to the 07+ VMAX trucks with the L76 6.0 If you look at the IFR table on a stock L76 truck it is a little different than most. The guys at Maggie were telling me that because of this and the way the truck regulates it pressure that the injectors were not working so well. Something to do with the spray pattern, which is good at 45 PSI but causes problems on pressure ramp up/down. Now that is what I was told and was asked to work with them on.

I don’t have the Maggie installed as of yet so as far as what symptoms it displays I am not sure of as yet. My guess is maybe a rich or lean spike. The IFR table I have from Maggie shows them trying to compensate for this. The line is nice and curved until the pressure rise decrease area in the IFR table and the curve turns into a huge dive up and back down. We believe this tuning for the pump / PSI reference is GMLAN based and there is not much we can do with that part of the truck/pump profile. They are currently perusing a different type of injector for these applications only. I am assuming something similar to the ZR1 type of injector. The ZR1 also has a fuel delivery set up very similar to the L76 but a little more exotic. They are on top of it and doing all that they can, at least they were honest up front about it most would prob not have said anything at all.

XLR8NSS

iTrader: (4)

I know there are some fuel pump tables in my 07+ 2500HD EFILive file. They are not active on my OS though as I don't have a variable pump.

I am going to find a EFI file of a 07+ VMAX, I want to take a look at the IFR table.

Drew is a smart guy, he'll figure things out. Keep us updated.

brantsz

yes he knows his stuff!!!

XLR8NSS

iTrader: (4)

Ok, I looked at a L76 VMAX file. You say you have 60psi at startup, 55psi at WOT, and 45psi at cruise. Check out P0586-P0589. I think they tell the control module what the pressure should be put at in different conditions.

Normal and Low flow(0589-0587) are at 300kpa(~44psi). This seems like your cruise setting. High flow(0586) is set to 370kpa(~54psi) which seems like your wot pressure. Cold flow(0588) is set to 400kpa(~59psi) which seems like your startup pressure. Wonder if those could just be set to all the same and you have one steady pressure.

brantsz

Awsome finde!!!! i need to get EFILive, there is quite a bit more parameters in there VS what i use. I dont see why you could not run a steady pressure OR what ever pressure works best with you injector. But it makes you wonder why GM has it set up this way? What pressure did the trucks run in the past? was it 55psi?

PM sent

zippy

Has anyone tried to elminate that system? Wheel to Wheel did that for their NNBS Rotrex kits (when they were still open) because they said something about fueling issue's with their injectors. I'm assuming this is what they were getting at.

Sebdane

Got the IFR table pretty well nailed down. Its not pretty, but it works. Averages LTFT= at idle +3, at part throttle/any load outside PE +/-0, feather throttle/steady state +4, decel/downhill +7. With Magna tune, only hit 4 fuel trim cells in closed loop at operating temp. Furthermore, I spend 90 percent of my time in cell 1 (avg 0 pull/add). No lean bank codes in 500 miles.

I will go ahead and put a plug in for Magna. This system is outstanding. Put it on at a family member's house in Colorado with my hand tools I carry with me (10 hour clean install). Went from 2000' elevation to 7000' , 3 hour drive up and under load, IAT's never went over 30 degrees above ambient. Power is excellent. Being realisitic, for a daily driven 4x4 street truck that needs to be reliable transportation for long work trips, I couldn't be more pleased with this system. Makes my procharger days seem like a nightmare lol. As far as the guys looking for better ET's in their trucks, the power/potential power is there with this system, stall and tire/gear ratioing combinations are what need to be tackled. 4l70, 3.73 or 4.10 with 20's=slow.
PS.......Joe at Left Coast 32 runs his buisness right. Excellent customer service/support. He has been top notch helping me (telling me what to do lol) with my IFR table and other tuning for this system.

Sebdane

HPtuners adding support

"Guys,

23 new params coming soon to control the fuel pressure module fitted to newer E38/67 vehicles. Also 4 new scanner PIDs to see the fuel pressure state, desired pressure, requested pressure and the injector pressure delta (used for the injector flow rate table).

Should be available in the next 2 weeks.

Chris..."