ls1 pcm conversion on 95 formula

[JoeliusZ28]

this conversion is the most valueable to someone that does their own tuning so you can take advantage of the additional parameters. otherwise you can just do a coil pack converstion on the stock PCM.

[ba94ta]

o ya it seems like it im planning on doing it when i fix all my body panels and floor pan ill be dropping my motor aswell

[formula57]

well not only does it give you better tuning paramaters it always allows for more power. the ls1 pcm has alot faster of a processing rate then the lt1 pcm. if you just use the ltcc kit you still wont get the gain that youd get off the ls1 pcm. the car runs so much more smoother. you have more control over all of your power curves plus you can reach an 8000 rpm limit and not hafta worry about shattering the opti which an lt1 pcm cant rev that high anyways. i was looking into the ltcc kit at first but then realized its just a waste of money. yea the ls1 pcm is a little bit more but youll have little to no problems down the road. plus your already for an ls1 swap

[Phantom409]

well not only does it give you better tuning paramaters it always allows for more power. the ls1 pcm has alot faster of a processing rate then the lt1 pcm. if you just use the ltcc kit you still wont get the gain that youd get off the ls1 pcm. the car runs so much more smoother. you have more control over all of your power curves plus you can reach an 8000 rpm limit and not hafta worry about shattering the opti which an lt1 pcm cant rev that high anyways. i was looking into the ltcc kit at first but then realized its just a waste of money. yea the ls1 pcm is a little bit more but youll have little to no problems down the road. plus your already for an ls1 swap

That would be my whole reason to do it.

Faster processing!

My 93 is like the slowest because of the chip I have to reflash all the time

I have also though of a FAST system too but it's double what you have into this.

[JoeliusZ28]

That would be my whole reason to do it.

Faster processing!

My 93 is like the slowest because of the chip I have to reflash all the time

I have also though of a FAST system too but it's double what you have into this.

what you are talking about is another benefit, what he was talking about is the PCM's ability to react to changing conditions faster, which i agree is definitely a benefit and will make the car run better.

I realize there is a power benefit, but im still not going to suggest its right for everyone.

[formula57]

I dont believe its right for everyone. I mainly did this conversion because i went threw 3 optis in under 2 years. Unless u know what your doing i dont suggest this conversion. It involves alot of research time and money to complete. It took about 3 solid nights to complete but almost 2 months of research and buying parts.

[ba94ta]

what kind of research are you talking?

[Kwazrollinz28]

i'd love to do this, but I wouldn't want them on my valve covers and on the firewall doesnt seem a good place either.

[Kwazrollinz28]

I dont believe its right for everyone. I mainly did this conversion because i went threw 3 optis in under 2 years. Unless u know what your doing i dont suggest this conversion. It involves alot of research time and money to complete. It took about 3 solid nights to complete but almost 2 months of research and buying parts.

who needs research we have you now

[formula57]

Alot of the research involved what parts needed to bought and how everything was going be put together. Ive seen pictures of coils being mounted on the intake but it doesnt look as good in my opinion. Valve cover mounting seems to look the cleanest. Only downfall is i hafta to take off the coils to put oil in it but thats only once a year sence i barely drive the car 1000 miles a year.

[Phantom409]

Well it looks like it will cost me more

The 93 harness is not workable with this setup according to EFI due to the injectors and wiring of the 93's.

So, for me to do this I would need to get a harness from a 94-97.

I already have the coils and you can get a PCM off ebay for 85.00.
My only thing is how will I hook the PCM to my port in my car because it's a 93 (obd1) and not an original obd2?
More research

BTW, EFI is very help full and they are great with there response's to e-mails.

[formula57]

if you get ahold of a 94 - 97 wiring harness youll just need to get the odb 2 connector harness and wire it in. one thing that youll deff need to know. when u wire it in the ls1 pcms use a different pin to read the pcm not like the lt1s. when i first finished the swap i couldnt read anything on a scanner so i had to get some wiring diagrams and found out the problem. ill get the exact pin location for you.

[JoeliusZ28]

yea if you could get all that info compiled into a how to that would be awesome. Im going to slowly start collecting parts for mine.

[formula57]

alright so i dug into my tool box and found all of my old wiring diagrams from the install.

heres what i got

on my 95 the dlc used pin 9 which is a tan wire. after the install the scanner now looks for a different pin to read the signal. the new signla comes from pin 2 on the dlc which is purple. i cut and spliced into the new pin and the scanner was able to read after that.

once i could get into the pcm i was able to start checking all my sensor data. of coarse i had numerous codes from the conversion but a couple were actually important.

i had a code for the camshaft position sensor not reading. if you go with the diy wiring harness it will come with a connector that will plug into the old opti connector located next to the intake manifold thatll plug into your new camshaft sensor. well the wires will not match up and you will need to repin the connector to get a camshaft signal. the old connector uses 4 wires and with the new harness you only use 3 wires for the new sensor.

the new pinning order will go:

opti connector new camshaft connector

12v red - 12v red
distributor low signal pnk/blk - reference low pnk/blk
high reso signal ppl/wht or lt blu/blk - cmp sensor signal imput brn/wht
low resolution signal red/blk will no longer be used. just pin it to the empty connector on the new harness.

i spent about an hour trying to figure out why i didnt have a cam signal and it was because of this reason. this should help save you some time.


you will need to do a crankshaft relearn after the install which can be done using a tech 2 or some type of scan tool that has the capabilities.

another problem ive run into is my cooling fans no longer turn on which the ls1 pcm. i know i pinned it all correctly but i think i had read something on how you will need to do something with the relays. i just installed a manual switch to get rid of that headache

the new coils 12v will need to be hooked up to 2 seperate 15 amp fuses. i eliminated the abs on my car so i used the fuse location for the abs and turned it into my coil fuses.

firing orders need to be changed sence the ls1 has a different firing order than the lt1. cylinders 2&3 and 7&4 have to be swapped when pinning the injectors and coils at the pcm.

if you have a 93 - 95 lt1 the harmonic balance snout will haft to be milled to the thickness of the new reluctor well the keep belt alignment in place.
i found a machine shop off 11 & gratiot. the guy only charged me $20. it took him less than a half hour and it aligned on the first try with no problems.

you will need to install a new crank key (gm# 12550096) for the reluctor well to line up with but that will only need to be done on 93 - 95 models sence they do not use a reluctor to begin with.

they tell you to use stock ls1 coils but i decided to use the coils from the trucks that have the heat sinks in the top. they stay colder and provide a stronger spark then the stock ls1 coils. perfect for a boosted or nitrous application or just for better fuel atomization

those are some things i can think of right now that will save you some time in your install. i wish i could of known some of that before hand it could have shaved alot of time off my install but its all part of learning so i have no complaints

if you have any other questions or if i can think of anything else i ran into ill let you know.

[formula57]

oh and i have set up my dyno tune for next week friday at 10 am.

i will let you know how it goes and what numbers im putting down here shortly