LSx PCM on a Grand National??

[Wasted Income]

Looking for some help/advice.

My brother and I are looking at using an LS1 ECM on his '87 Buick Grand National. We want to be able to tune it without having to send the chips off. We also want to go to a custom OS and go to speed density.

Now we were thinking about using a calibration from a 2002 4.3L Vortec.

Things we have going for us:
-Both a 4.3L and a 3.8L have the same firing order, and both are V6.
-The 3.8L already is SFI with a cam and crank sensor, distributorless ignition, knock sensor, MAF, MAP, etc, etc.


Things we have against us:
-The 4.3L Vortec has a distributor, the GN has a crank triggered ignition.
-The sensors are not the same. Example is the crank position sensor. I have read that the GN uses a halleffect sensor, while the LSx uses something else.

Questions:
-Would we be better off to use the LSx harness and LSx sensors on the GN, or would we be better off to splice the GN sensors into the LS wiring, and try to change the required values in the ECM?
-How on earth would we fire the individual coils sequentially? Can we do a wasted spark type setup?
-Can we modify a 5.3L tune to only use 6 injectors and 6 coils? Or would it be better to modify a 4.3L tune to fire coils sequentially, instead of a distributor?
-How difficult would it be to adapt a GN crank position sensor to an LSx ECM, or vice versa....install an LSx setup on the GN engine??

I'm certainly have more questions, but this ought to get the gears grinding of the brilliant tuners and PROGRAMMERS out there :master: :master:

I guess the biggest question that we have is: How does a newer 4.3L Vortec fire the distributor? Is the option still there to fire individual coils? Is there something in the code that Ross or Paul could "enable"? If we get this working correctly, we'll plaster http://www.efilive.com/images_resellers/btn_efilive.jpghttp://www.efilive.com/images_resellers/btn_efilive.jpghttp://www.efilive.com/images_resellers/btn_efilive.jpghttp://www.efilive.com/images_resellers/btn_efilive.jpg all over the car!!!!

[ChipsByAl]

Is this GM heavily modified? Or is it still actually street-able? You could feasably use the Vortec "LS1" PCM for the 4.3, but plan on getting a HEI distributor to distribute the spark. There were no V6 engines that had CNP with the LSX PCM. You would need to do some modifications to the crank and cam sensor signals, it has been a long time since I fiddled with the GN combination. Someone else may be able to chime in.
AL

[zapp168]

I am sorry I have nothing to add except this is A great idea that I have been pondering myself....I want to be able to convert my older v8's to the LSx PCM for ease of tuning....If you could change the firing order to 18436572 I know I could rig up some kind of crank and cam sensor

[ChipsByAl]

If you are up to the demanding and exacting type of job of adding the crank and cam reluctors and sensors to the early engines, it can be done. The PCM only knows to pulse a driver and a coil at a certain time and duration. Who is to say you cannot change what cylinder the coils and injectors are located on.
Al

[Dennis93TA]

That is a good point Al. That's alot simpler than what i was thinking.

[GMPX]

As Al said, simply move the injector / spark outputs to the correct cylinder, however, the main issue is the PCM trigger signals are pretty much application specific. So you are really locked in to whatever GM put in the LS1 PCM, you need to adapt your GN sensors to match the 4.3L.
Would be a nice thing though given our custom OS goes up to 285kPa.

Cheers,
Ross

[Chuck L.]

Accel dualsync dist has both a cam and a crank signal output. Not sure if they make that dist for a V-sicks...
We use them in my HEMI, and in the Vette, to signal the ACCEL Gen 7 system.

[LSRacing]

We are currntly runing the LS1 PCM on 10 Third Gen Camaros and Firebirds. The tuning ability of EFILive makes this swap pretty easy. We have ran COS 5 on 2 of theses and tuned for boost with great results. To read up on this conversion, check out this site: http://www.thirdgen.org/techboard/tpi/383323-tpi-obdii-thoughts-opinions.html

Im sure that the swap to a GN would not be too much trouble. There would be some figuring out to do with the tune, but the hardware seems like it would work. Post your questions there and you may get the answers you need to make this work.

[Lextech]

You could probably use the Vortec V-6 crank reluctor ring and use a Buick V-6 distributor with Vortec V-6 innards. As for changing the firing order for other V-8 engines, that shouldn't be a problem except for MAYBE having B1 and B2 Oxygen sensors match up to their assigned cylinders. Example--If you accidentally get the O2 sensor pigtails crossed, as in B1 ends up on B2 and B2
ends up on B1-- It will cause one bank to go full rich and the other bank to go full lean when in closed loop.

Don't ask me how I know this---Its too painful.

[zapp168]

You could probably use the Vortec V-6 crank reluctor ring and use a Buick V-6 distributor with Vortec V-6 innards. As for changing the firing order for other V-8 engines, that shouldn't be a problem except for MAYBE having B1 and B2 Oxygen sensors match up to their assigned cylinders. Example--If you accidentally get the O2 sensor pigtails crossed, as in B1 ends up on B2 and B2
ends up on B1-- It will cause one bank to go full rich and the other bank to go full lean when in closed loop.

Don't ask me how I know this---Its too painful.

I went through that......It is a VERY painful lesson!!!!
I thought about the firing order after I posted it and was going to get back on and ask if swapping things around would work, looks like it might:). I also remember seeing Holley and Edelbrock making intakes for their fuel injection system with a throttle body on it. I have a 71 Camaro with a 400 and I just keep staring at the carb thinking....You gotta go:Throwup:. Plus I seem to have a need for dozens of unfinished projects around, what is one more? :eek:

[1meangto]

has anyone tried this swap yet?? I just bought a very modded 86 gn and it"s bank fire with a dfi 6 yuck I really want to try the obd II thing any more info"d be awesome.....

[Bruce Melton]

We are running a hyped LS7 in a race car with a MSD 6AL which is very straightforward. There may be advantages to running a carb and using electronic ignition?

[Ira]

I am sorry I have nothing to add except this is A great idea that I have been pondering myself....I want to be able to convert my older v8's to the LSx PCM for ease of tuning....If you could change the firing order to 18436572 I know I could rig up some kind of crank and cam sensor


Just move the plug wires or coils to match the cam, the ECM doesn't know about firing order.

Ira

[Highlander]

funny.. I think the lt1 pcm did have a firing order.. So.. would this work for the LT1??????