350 Vortec with TBI intake Question

Hello everyone! I have a 1995 GMC 1500 4x4 and I just replaced the engine. I put together a Vortec with the following specs: bored .030 over, the block was decked, dished pistons, heads surfaced and rebuilt, new roller cam (.450/.433 lift), GM intake. I am running the stock throttle body, injectors, regulator and fuel pump. The timing is set to 12 deg advanced with EST wire unplugged. It does not run right, I was reading about programming a chip for this but had some questions. 1) what should I look for in a programmer? can I program right from the ALDL, ECM, EPROM or memcal? 2) is TunerCat the best program for this? 3) has anyone built this exact (or close to) engine? I am excited to get this running right.. Thanks!!

:welcome:

An alternate option to a chip is a Moates.net Ostrich 2.0 chip emulator: http://www.moates.net/ostrich-20-the....html?cPath=64

The Ostrich 2.0 allows tuning changes, with the engine running!:thumbsup:

The Ostrich 2.0 will work with either TunerCats or TunerPro RT. I favor TunerPro RT for the 1995 GMC: http://www.tunerpro.net/downloadApp.htm

I've worked with similar engines like the one you built. The stock TBI timing table in your current chip is not going to work correctly with Vortec heads. I modified a timing table from a 1998 Vortec L31 computer for the TBI Vortec engines I've worked with. http://www.gearhead-efi.com/Fuel-Inj...-Throttle-ONLY!

I would recommend using a Wide Band O2 sensor to correct the fuel tables for your TBI Vortec engine: see attached screen shot

dave w

Thanks Dave!! I'm gonna look into that. It looks like I'll need the adapter for the EPROM but other than that it looks pretty straightforward.. I will look into the wide band O2 sensor, I think the stock one is 1 wire, so I'll have to figure that out. Do you have any advice as far as the fuel system goes? This is a work truck, pulling small (less than 5000 lb) trailers and just a run around truck for one of my employees..

The WBO2 requires an additional O2 sensor bung welded into the exhaust. The WBO2 does not control the fuel like the single wire O2 does. The WBO2 iss used to supply tuning data. Once the tuning is complete, the WBO2 can be removed.


The stock fuel system will work OK. It would be a good idea to get an adjustable fuel pressure regulator to get the fuel to 15 ~ 16 PSI for the stock 61 lb injectors.

dave w

Thanks, I have another general question: I have a 98, 99 and 2 2001 gmc trucks. I want to tune them. I have an ELM327 cable hooked up to my laptop and I own the total car diagnostic suite. How do I get the data from the ecm to my laptop? seems like a silly question but I have to be missing something?? any advice? i have installed the tunerpro program, I get how to look at the tables and data but can't figure out how to get the data to my computer..

The OBD2 stuff is a bit more expensive. You can use the ELM327 to datalog, but not for tuning or looking at tables. HP Tuners is one of the more popular ways to tune the '99 and later stuff (it's what I use). There's also EFI Live and TunerCat. Most of them have a demo you can try to see how you like the software, but you'll have to buy the hardware (and possibly licensing) to do any tuning.