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View Full Version : 1996 7.4ltr vortec diagnostics port question



ari666
October 17th, 2011, 11:48 AM
hello all.

i am looking at installing a 7.4ltr into my 1966 impala. i recieved a modified engine harness to go with the engine, but the previous owner removed the wires going to the OBD2 diagnostics port. without it i am useless.

am i correct in assuming that the diagnostics port should be:

pin 16: constant +
pin 4: earth
pin 5: earth
pin2: serial data

are these the only 4 wires i need to get efi live to speak to the ecu? i have not purchased efi live yet. i have a cable (ebay rubbish) which will allow me to read DTC's and once i get that to work i will go ahead and order efilive.

also: 0411 swap is on the cards, but i just want to get the basic wiring done to the point where itll start and drive. then ill look at swaps later. i plan on headwork/cam/injectors so ditching the blackbox is a certainty, but i like to do one thing at a time.

install>test, install>test etc.

thanks in advance.

Taz
October 18th, 2011, 06:12 AM
Hello Ari666,

The pinouts you list above for the DLC (OBD-II) port are correct for your application. The downside to not doing the 0411 swap now, is the cost of eventually licencing both controllers, and the limited tuning potential of the Black Box Vortec controller.

The 0411 swap is very straight forward - usually little or no cutting / slicing / or re-crimping required. The PCM pins are the same in both controllers (Micro-Pack 100W) - as close to a "plug and play" solution as you will ever get.


Regards,
Taz

ari666
October 18th, 2011, 02:24 PM
dont get me wrong, i have every intention to do the swap. even just for the sake of killing the rev limiter, let alone the rest of the benefits. i am just not going to do it yet

am running on a very tight budget and just want to see her running in stock form before moving on to modifications.

i thought efilive gave you 4 vin#s, am i confusing that with another program?

Taz
October 18th, 2011, 02:30 PM
The V2 would have originally included 2 tuning licences. Regarding a tight budget - try this math - a used LS1-B PCM can be purchased for $10 to $40. Doing the PCM swap will cost only your time - no parts. A tuning licence is worth $125. You would save between $85 to $115 - if you do the PCM swap now, rather than later.


Regards,
Taz

L31Sleeper
October 18th, 2011, 03:33 PM
The V2 would have originally included 2 tuning licences. Regarding a tight budget - try this math - a used LS1-B PCM can be purchased for $10 to $40. Doing the PCM swap will cost only your time - no parts. A tuning licence is worth $125. You would save between $85 to $115 - if you do the PCM swap now, rather than later.


Regards,
Taz

Um you can't license a 96 or 97 black box..........problem solved.

-Justin

ari666
October 18th, 2011, 05:09 PM
ah yes. couple of things, the black box supplied is the later model 98-00 16263494 which i believe is supported (forgot to mention that small point, sorry)

also, got any links to the 10 buck units who will post to OZ? (forgot to mention that point as well) average here is about 300 bucks.

L31Sleeper
October 18th, 2011, 05:45 PM
Well getting it running shouldn't require you to tune it.
Then swap the PCM before you start tuning.

I want to know where to get them for $10 ANYWHERE !!

Taz
October 19th, 2011, 12:38 AM
Well getting it running shouldn't require you to tune it.
Then swap the PCM before you start tuning.

What is your plan for VATS in the PCM (B1039) ? Had assumed you would disable this using EFILive.



I want to know where to get them for $10 ANYWHERE !!

You gentlemen not have auto recyclers (wrecking yards) where you live ? I generally pay $40 for an LS1-B PCM if it is "on the shelf" - $25 if I buy 10 at a time. At my local "pick your own parts" auto recycler I pay $10 if I remove it from the vehicle myself - $20 if the C1 and C2 connectors are still attached. There are auto recyclers here that list these at $200 - but they won't be selling many.


Regards,
Taz

L31Sleeper
October 19th, 2011, 04:56 AM
I use http://stores.ebay.com/SpareECM $89 bux Great service.
Most of the auto recyclers in my area are hip to what "market value" is.

-Justin

Taz
October 19th, 2011, 05:12 AM
Spare ECM provides a good service - but those PCMs are cleaned and reprogrammed - all for that price.

Try www.car-part.com (http://www.car-part.com) most mainstream auto recyclers in North America are listed. Prices in this area range for $35 to $200 for an LS1-B PCM.

On my last trip to the southern states for a project vehicle, I picked up a truck load of parts at Summit Racing, and 2 low mileage LR4 4.8 L engines from an auto recycler that was clearing out older inventory (engines were 2000 model year) - paid $100 for each engine.

There are deals out there ....


Regards,
Taz

ari666
October 19th, 2011, 11:44 AM
What is your plan for VATS in the PCM (B1039) ? Had assumed you would disable this using EFILive.

thanks for the links ;) i will have a closer look at those guys when i am home from work. but 89 bucks sounds like the right price to me. i will need to do more than just disable the VATS (actually, i kinda would like to get it working, just as an additional security feature) i want to kill off 2 of the 4 O2's, kill off the MAF and try and figure out how to run with no VSS temporarily (running a 40 year old 2 speed powerglide till i can afford to build a turbo700) to save myself another 200 bucks.

we have wreckers here, but dont have anywhere near as many models running that ECU. i think it was limited to 1 or 2 series of holden commodore. so wreckers are charging mental amounts for them. 300 bucks is the BEST price i could find. there was one guy wanting 950!!!