LA3 swap problem

[dlvandyke]

I did the LA3 swap as outlined, checked 3 different sources, double and triple checked the repin. Problem is the car will not boost over 10 psi, doesn't seem to be in premium mode either because the performance is poor. The car ran great before the swap, just pings a little during high boost in premium mode. Searched but didn't find an answer.
TIA
Dani

[richsvo]

Sounds like the premium fuel switch is not wired correctly. It would default to the "regular" mode, which would only give you about 10 psi. Wiring in the switch would let you select between the 10 psi (regular) and the 15 psi (premium) settings. It is shown on the schematics, and off the top of my head...I think somewhere around pin 34 and ground; but don't quote me on that...
HTH,
Rich

[SVOBart]

I have noticed that some of the repin guides neglect to tell you to relocate the pin for the octane switch. SVO EECs use pin 30, LA3s use pin 24. Move that and you should be set.

Also, if you have one of the earlier year boost controllers it will not work with a later model EEC. You'll have to run a manual controller like a Gillis.

[SVOeric]

you know that when you do a la3 swap, you also have to use a manual boost controller. The svo boost controller, and the t-bird boost controller aren't on the same pins.

I haven't looked at it, but you may be able to re-pin the controller, and have it work as well.

[SVOBart]

You can re-pin the later style (85.5-86) but if someone has a 84 style controller I've read it won't work at all, even if it is re-pinned. I had already installed a Gillis style valve when I did the swap, so it was a non-issue for me.

[SVOeric]

yep bart -- that's where I was going with that.

[AT6svo]

The main thing is that the ECU gets the command (via the prem switch) such that it can use the appropriate timing tables.

This link to Rob's page my help out:

http://www.svo1fast4.com/la3.html

[dlvandyke]

It is an '86 SVO, should have mentioned that, and Rob's page is one that I used. I didn't know a manual boost controller was necessary on mine.
Thanks all
Dani

[andyshyers]

I have just installed an LA3 in place of my PE in my '86 SVO. I wired it as follows:
PE - LA3
43 - 27 VAF
25 - 43 VAT
35 - 33 EGR S/O
32 - 31 BCS
30 - 24 OCT ADJ

Now I am unable to achieve more than 10psi boost. Has anyone out there switched from a PE to LA3 and retained the use of the premium fuel switch to control timing and boost? I've had suggestions to just connect pins 24 and 46 through the existing relay, but when I pulled the relay system out I found that they were connected through the existing relay!

I'm going to save the PE and plan on running a Tweecer with LA3, but I want to ensure it's functioning properly before I hook up the Tweecer. Any help would be appreciated!!!

Thanks!

[BrianO]

I have just installed an LA3 in place of my PE in my '86 SVO. I wired it as follows:
PE - LA3
43 - 27 VAF
25 - 43 VAT
35 - 33 EGR S/O
32 - 31 BCS
30 - 24 OCT ADJ

Now I am unable to achieve more than 10psi boost. Has anyone out there switched from a PE to LA3 and retained the use of the premium fuel switch to control timing and boost? I've had suggestions to just connect pins 24 and 46 through the existing relay, but when I pulled the relay system out I found that they were connected through the existing relay!

I'm going to save the PE and plan on running a Tweecer with LA3, but I want to ensure it's functioning properly before I hook up the Tweecer. Any help would be appreciated!!!

Thanks!

what was the outcome of this?? buddy is seeing the exact same thing going from PE to LA series on his 86.

are the BCS's not compatible with the LA ecu's?

[andyshyers]

Here's what I found:
*You need the VSS hooked up for the LA3 to reference the BCS table correctly.
*The BCS tables in the LA3 work well for an IHI, not so well for a T4/T3 hybrid.
*If you have a tuner it's possible to modify the tables to work well with different combos.

I spend a sizable amount of time working on the tables to get the boost I wanted out of my new turbo, and once I get my latest exhaust finished, I'll be back at it again.

[BrianO]

vehicle speed sensor? there isn't one is there?

and just to clarify.. this is for an 86 correct?..coming from a PE..

vss is pin 3 on the LA3 I think..

[andyshyers]

Nope, you will have to add one. I was lucky, my SVO already had the harness installed from the factory (?!?!) so all I had to do was to go get the sensor from the wrecking yard and grab a new speedo cable.

From what I understand of the LA3 series, it looks like there may be different boost strategies depending on the year of donor car. I have not tried my second LA3 to see if anything is different yet.

[BrianO]

so.. the octane switch will still work provided pinned correctly, but if you want the stock BCS on the 86 SVO's to work you'll need a VSS..correct?

Otherwise you can just go to a manual boost controller I assume

[andyshyers]

Yes,
That's correct.