16188051 Howell ECU Confusion for Gen II LT1 Swapped S10 Blazer

[Toni.Tepes]

Hello,

Long story short, I got a 1985 S10 Blazer, an engine, a harness and an ECM and I have been finishing up the swap for a few months now. It was mid-project when I got it, so I have taken over a great deal of work, but I'm happy to say that it's mostly running great now.

I want to put a tune in it, but there are a couple of problems holding me up



Some Details: Gen II LT1 Swapped 1985 S10 Blazer w/4L60E
- Short Ram intake
- Speedway Headers
- Full exhaust w/ Flowmaster mufflers that dump right before real axle (No Cats)
- NGK G Power Platinum Spark Plug 3403
- Brand new opti
- MSD Ignition 8226 Blaster Coil
- Taylor Spark Plug Wires 74227
- Unknown LSD (I believe it is 2.73. The tire diameter is 26.1)
- EGR Delete
- New O2s
- Bosch 3 24 LB Injectors
- AC Delete



1. After using FlashHack to read the calibration, I noticed in EEHack that the ECM is flashed as a 1995 Cadillac. (Also using EEX Definition in TunerProRt)
It is a Howell 16188051 aftermarket ECM #HFY47TE ( https://howellefi.com/product/lt1-ec...h-4l60e-trans/ )


- Should I figure out how to flash this ECM for another vehicle and if so which one?




2. I'm not sure what the LT1 is out of.
It's got iron heads, so it's not a vette but I have no idea what it's out of or if it's 94 or 95.


- How much does this matter?




3. It has a bad stutter under hard acceleration (after switching to closed loop operation)
If I give it enough throttle, I could stall it out. It happens between idle and maybe 2000 RPM. But if I'm at a higher RPM and step on it, it pulls hard. I have not tested the fuel pressure yet but that is my next move. Besides the fuel pressure check, I have done everything else, including checking for vacuum leaks.


- Do you think there is something in the existing tune that could be doing this?




I have attached a zip folder with my stock .bin, .eedata, and .csv located inside of it

Thanks!

[1project2many]

There are folks that have more LT1 experience than I have and I'm hopeful they'll chime in.

I believe the only cars with aluminum heads were Vettes and F cars so the Cadillac calibration could be a decent start. The injector values in the ecm really need to match the injectors you're using. Make sure the gear ratio and tire diameter are correct. I believe shift points are based on vehicle speed and if the speed calculations are off, so are the shift points. Once the injector corrrections are good you can watch the O2 readings to see if they are lean or rich under light throttle, before the spitting occurs. You can also do plug cuts to see if the plugs are black with carbon or if they're super clean which may indicate a lean engine.

[Toni.Tepes]

Yeah, its definitely not a Vette. I wish. So you're saying that I should try to find a stock Cadillac bin and start there? I'm pretty sure the injector were the same #. One of the old ones was bad and now its way better, but I still get the stutter. Also, today found out it does the stutter even before closed loop starts. Thanks for the reply, hopefully someone can shed some more light.

[1project2many]

I'm not sure a stock calibration will be any better than what you have now. But it will allow you to start from scratch.

[Toni.Tepes]

Thanks for the input. Good idea

Can someone else chime in? Wondering if I HAVE to use a Cadi bin

please help

[1project2many]

You don't have to use the Cadillac calibration.

[Toni.Tepes]

So does that mean that I can use any bin I see fit?

As in, I can use any EE 94-95 LT1 bin since all I have is the engine?


Thanks for the reply