Super long post warning…

I will post a few pics of the injector data sent to me by the injector manufacturer that I modified my ECU with and I can't post the datalog from HPTuners of me cranking the truck but if you'd like to see that, I can send it to you.

I’m having issues getting my 2003 Silverado 1500 5.3 to start after my almost complete turbo build. Here’s some build details and what I’ve done so far..


Factory P59 ECU.

153,XXX mile, cammed 5.3 LM7 (factory to the truck, not swapped).

4L80E swap with an HD2 shift kit with BP Swap Harness and I pinned in the second speed sensor. It is segment swapped and the computer is reading it correctly as far as I can tell. 3600 Triple Disk Converter.

ARP Studs and new factory MLS gaskets.

850cc Snake Eater Performance injectors.

Stock intake manifold, brand new gaskets.

Fahler Speed Log manifold T6 adapter with an S475 turbo on it. Cold side and hot side are NOT complete yet. I have the 3” VSRacing intercooler installed with couplers on it but just sitting there so far as I need welding done and clamps for the couplers. Hot side is just open, no piping or wideband yet so basically the truck is just open headers right now. BBK Short tube header is on the driver’s side.

NGK TR6 plugs gapped to .028-.029 as recommended for boost goals on Sloppy Mechanics Wiki

Factory coils and plug wires.

PAC 1218 Springs

All required gaskets were done. I know this isn’t relevant to a no start condition necessarily but I’m trying to be as inclusive as I can.

Walbro 450 fuel pump, haven’t put in 10 micron fuel filter yet or 15 amp fuse as they recommend but I’m sure that wouldn’t cause a no start. Factory fuel lines. Definitely getting fuel pressure.

4 an turbo oil feed running from oil pan using an ICT Billet adapter fitting.

12AN turbo drain falling straight into oil pan above oil level.

Brand new oil pan gasket including RTV at corners where block meets together.

LS1 Style 3Bar MAP sensor by EFI Source (not tuned for yet).

Wastegate and Blowoff are not on the truck yet.

O2 Sensors are off minus upstreams (I think? Truck was tuned by a professional for this cam and I think that’s what he said. Can’t remember).

Still on a MAF tune so I have that plugged in but with no intake, it’s just sitting there right now but it is plugged in.


Battery is at 11.9 V so I pulled my car in today and had the jumper cables on it while running a data log on my truck, brought battery to between 13-13.4 Volts.

The truck was a 4WD truck. I put a 2WD 4L80E in it and have removed the transfer case, front differential, axle shafts, front driveshaft, anything to do with 4WD is physically gone minus the hanging connectors with no where to be plugged into anymore.

The truck will crank but HPTuners says it’s only cranking at about 150 RPM (sounds normal so I’m not sure how accurate that is) and is only reading data from two injectors. I will post the injector data that I modified at the end of this post. Snake Eater Performance had options to choose from in the excel they sent me stating that I need to pick the data that is most similar to my stock file. They had LS1, LS2, and LS3 data to choose from. The LS1 file was the closest I thought so I copy and pasted that date over to the sections “Injector Flow Rate vs KPA VAC and Injector Offset vs Battery Voltage vs KPA VAC.” There was some Short Pulse Limit info to drag over as well but for some reason, it will not let me make those changes.

I have a data log live scan of me cranking the truck that I can send if anyone is curious to see what’s going on while cranking.

My suspicions are…

Something unplugged currently that was relevant to 4WD or something may be getting in the way of starting.

Does the 3 Bar MAP need tuned in first? Does the 4WD stuff need to be turned off in HPTuners somehow? Do I need the wideband installed and just one O2 sensor? I’m totally lost and brand new at this so I have no clue where to look.


On the data log, it shows two injectors firing during crank even after I swapped over the data from the injector spreadsheet.

I guess I should mention, truck was running perfectly when parked to begin the build.

I know it needs professionally tuned and it will be, I’d just like to get it running before I take it for a dyno tune so I’m not charged even more for them to figure out my no start condition. I’m sure this is something simple but being the first time I’ve done anything in depth, I’m not surprised I’m in this situation.

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Off the bat i'd eitehr unhook the MAF and put in the SD patch or just try it with it unhooked. With it plugged in but no plumbing you're telling the ECU you have no airflow. you do need the MAP sensor put into the ECU. Those two things should get it to start hopefully.

 

T

Thanks for the reply! Any advice on where to look for guidance on the SD patch? I’m assuming that stands for speed density. As far as the MAP goes, I’m sure I can easily find a YouTube video on how to tune that in.

 

https://www.hptuners.com/help/vcm_editor_parameters_gm_os.htm