PDA

View Full Version : new engine questions



garrinchilders
July 18th, 2009, 04:07 AM
I have:
1996 SWB GMC 1500 4x4 4.3 5speed (STOCK)

I obtained:
Fully Dressed Vortec 5.7 from a 97-98 chevrolet 1500 LWB 4x4 automatic
ECU
Engine Wiring Harness
Exhaust system


My question:

I want to swap the engines, and keep my 5speed tranny. Will the ECU from the auto tranny truck work in my truck without a reflash and without throwing a ton of trans codes?

From the research I have done on my own, I have found that I just have to relocate the motor mounts, replace the fan shroud from the donor truck and it will pretty much be straight forward. I just want to get a hand on the electronics portion of the swap. I want to have a sound reliable daily driver with NO Service Engine Soon Light.

mr.prick
July 18th, 2009, 04:43 AM
No,
other than the trans DTCs there are other tables that will need to be changed.
I don't have a tune for a 97-98 chevrolet 1500 LWB 4x4 with a manual trans so
I can't tell you exactly what needs to be changed but manual and auto trans files are different.

garrinchilders
July 18th, 2009, 05:04 AM
To the best of my knowledge GM didn't make any of the SWB 1500 5.7 4x4's in 5speed configuration. So if they auto ECU won't start and run the truck without the transmission in place, The only options are:

A: Convert to an auto trans :-( BOOO (not happening)
B: Leave the 4.3 in place and fix my spider injection so I can get more that 6MPG
C: find a place to send my ECU off to that will burn it for a 5.7 with a 5speed

I am leaning towards option C! I don't want to spend a whole lot of money to do this, I know it has been done before, and someone out there has the correct mapping on file just sitting there. Any suggestions on where I would be able to find a reputable place to send my precious ECU for reflashing?

I don't want alot of downtime, as the engine swap will only take 1 day, and from what I understand it doesn't take a person a lot of time and effort to reflash one. I don't want to pay someone half of what it would cost me to buy the flashing software and scanner to fix me up. I don't feel the need to pay someone for half of their machine when I could double the money and charge my friends nothing to remove speed limiters and raise rev limiters and correct for tire sizing and what not....

What would have happened if I hadnt asked if this would work, and I just hooked it all up and started the truck? would it have run at all? Or does the trans have to be hooked up for the engine to start? If it would have started would the engine have ran properly?

mr.prick
July 18th, 2009, 06:34 AM
Try wait4me (http://forum.efilive.com/member.php?u=444)

To the best of my knowledge GM didn't make any of the SWB 1500 5.7 4x4's in 5speed configuration.
That would explain why I don't have a .bin for it. :hihi: