jcorenman

Sure, no problem. I did that on our '90GT, because the diagnostic connector on later cars is under the pass-side "hump" and the cover won't fit with the plug in place.

So I got an extra ST2 "pigtail" from John, a cable with the 8-pin mini-DIN at one end to plug into the ST2 box and just wires on the other end which I tapped into the various connection points on the CE panel.

I'll get my notes out and update this with the connection info.

dprantl

That would be cool. I don't like having my cover stick up because my ST2 is always connected. I was actually thinking of unbolting the diagnostic socket and relocating it a little so I can properly fit the cover.

Dan
'91 928GT S/C 475hp/460lb.ft

Rob Edwards

+1. The socket is held with 2 small philips head screws, mine was flopping around because the PO ran a ton of stereo wiring thru the area and disrupted the fan controller and diagnostic socket. It'd be cool to be able to put an auxilliary socket somewhere closer to the CE panel, perhaps closer to the center console for futureproofing with the new carputer consoles coming to market....

jcorenman

Agreed. The 12-pin diagnostic connector for the (87)/88 cars is more conveniently located, but those connectors are NLA and not the best choice for an upgrade in any event.

What I did for our GT was hard-wire a pigtail to the CE that goes direct to the ST2, but a cable disconnect near the CE would be much nicer. The ST2 pigtail also has very small wires and a disconnect would be a convenient place to transition to a more robust wire gauge for connection to the various wire harness points.

What I am envisioning is a "installation kit" as an accessory to the ST2, which would provide a way to hard-wire the ST2 if desired as well as organizing the various WBO2 connections (the LC-1 comes with a bunch of flying leads that are begging for a connector) and make sure the grounds are properly addressed, etc.

I need to confirm the pigtail connection with John, I've got two sets of notes which say different things
He's away for a few days, in the meantime I will research connectors.

Cheers,

the flyin' scotsman

Jim...............did you leave the WBO2 connected? If so how did you run those wires.

Andrew.............if you have access to the Moorehouse cds check out the 87 and 88 MY spec books. The 87 talks about being diag ready with a pic of the diag port where the 88 book talks much about the diag tool and readings thereof.

You'll recall the 87 ecus do not have readable eproms; you have to install 88 chips...............I have spares as my car is now fitted with PEMs.

jcorenman

Yes, the WBO2 is installed in addition to the stock NBO2. The GT has a Louie-built 2.5" exhaust, with the NBO2 peeking into the top of the "X" in about the same location as stock. I added a second bung on the right side, downstream of the "X" so it presumably gets gas from both sides.

I could have also replaced the NBO2 with the WBO2 and replaced that signal with the WBO2's simulated-NBO2 output, but keeping them independent seemed like a good idea at the time. In retrospect, the LC-1 WBO2 has been reliable so why not simplify it.

The LC-1 (along with the ST2) is fed 12v from the CE panel, P-25 (dedicated 5A feed to the diag connector for a '90) and is powered up whenever the ignition is on. John's recommendation is to tap WBO2 power from the NBO2 sensor, that is OK also and is powered up whenever the engine is running.

The current wiring is a rat's nest, artfully hidden by the floorboard. I tapped into the CE wires by unplugging the appropriate CE connector, removing the contact and soldering another wire piggy-back to the terminal. A royal pain but reasonably tidy, and reversible (except for a bit of solder). I then used 1/4" spade-connectors (fully-insulated marine type) to make the various connections between LC-1, ST2 and the CE panel. For a ground point I used one of the LH/EZK-chassis mounting bolts. It works but could be a lot neater, and I am serious about wanting to sort out an install-kit.

AO

Well just a quick update...

My '87 has the connector. Serial number is 0086, so I think the statement that some of the early 87's didn't have the port may be a myth. This is one of the earliest '87's



So, I decided to go ahead and load up the PEMs and see if I could get the STer to hook up.

First up was the EZK.



Opened it up, and PEM is installed.



Unfortunately, this one isn't going to get dremeled





So this is the best way I can sandwich it back together.





Next up is the LH with some pizza and beer! Yum!



Unmolested LH... be careful!



In the end, I hooked up the STer, and it it connected to the LH, but it would not connect to the EZK. I wonder if there is anything special about the early EZK's? Anyone had a problem with the early EZKs?

sendarius

I don't know if it just the perspective in photo 3, but it LOOKS to me as though the PEM is one pin out of alignment in the socket.

My EZK (in my 88S4) looked just like yours, and I (carefully) Dremeled the offending PCB as per John Speake's instructions with no issues. It certainly looks like there will be issues from doing so, but I haven't had any.

jcorenman

Get a bigger dremel... Seriously, take a look at the underside of mine, above (in the dental mirror)... There were parts there, once... just run a vacuum while dremel'ing and and clean up all of the shattered wreckage so that there are no shorts between pins.

Those are small filter capacitors, probably there to meet European EMI (radio interference) standards and omitted completely on later cars (our '88 had them, the '90 did not).

Shouldn't be an issue... Does the car run? If so, that means you didn't kill the EZK with the tortured reassembly.

So if the ST2 talks to the LH and not the EZK, and the car runs, then there must be a problem with the K or L-bus connections to the EZK. I would unplug the two modules (with battery disconnected of course) and check continuity from the diagnostic connector to the LH and EZK connectors, for both K and L-bus.

Cheers,

jcorenman

I think it is perspective, but hard to tell. They key question is whether the car runs, if so then the PEM is in correctly.

Don't grieve the missing parts, our '90 never had them and it makes quite a bit more HP

I think Andrew's off to bed, getting late here also... Carry on!

Cheers,

Bill Ball

So, Andrew, what was that other connector with all the brown wires and the wrong pinout?

sendarius

That was the bit I sweated over when I installed my first set of PEMs - will the thing start?

When I first powered things up after installing the PEMs, the ST2 told me all sorts of odd things - IIRC my car was suddenly a 91 octane, manual, with no cats. I knew that wasn't what the coding plug said, and I was leaning against the auto trans shifter. It caused me to doubt my work for a moment or two.

The electronics apparently don't read the coding plug until attempted engine start because once I actually cranked the engine into life all the status & configuration indicators were correct.

Strangely (or not, I'm not sure), the car starts easier and idles smoother since the swap. At the time the difference was so marked, that I wondered if the PEMs as supplied carry later map versions.

AO

Got it. Didn't realize that those were sacrificial resistors. I'll dremel it once I can get the EZK to work.

I didn't even try to start the car because I couldn't load an image onto the PEM.

I'll check fro continuity tonight if the weather cooperates. I may also try to swap the PEMs to see if the problem follows.

Jim is right. PEM was fully seated. I may try swapping PEM to see if the problem follows or stays.

Don't know. That was on another guy's car. I'll dig into it when I see him/it again. I'm just as curious as the rest of you.

jcorenman

Capacitors, but that doesn't matter-- I would go ahead and modify the board just in case the problem is somehow related to the EZK not being reassembled properly (ground connnections, for example).

The last set of PEM's I got were pre-loaded (and marked) for LH and EZK. It looks like yours are not marked for each box which I think means that they are pre-loaded for the LH.

A PEM with the LH binary image will be recognized by the ST in an EZK, and can be loaded with an EZK image-- but can't run the EZK until it gets loaded.

Weather won't matter, it should have continuity anyway. But if the EZK image isn't loaded then you can't tell whether it is a PEM or EZK problem , or a bus problem.

That would be a good test. You will need to reload the PEM of course (ST's File/New menu) but a PEM from an LH will be recognized in the EZK, and allow the EZK binary file to be uploaded. And similarly in the LH, if the PEM in the EZK is good then it can be swapped to the LH and reloaded.

Question: Does the EZK's PEM show up in ST's Eprom page but won't load? Or is it not seen at all by ST?

And I assume this ST2 box has worked OK with EZK's on other cars?

AO

That's what I thought. A last resort, I can plug the PEM into my GT's EZK put an image on it and then try it (but GT is in Michigan, I'm in Ohio during the week... )

It's raining + no garage = no 928 work.

It came up on the screen that there was a PEM module installed, but when it tried to communicate, it said it couldn't (I forget the actual message, now.)

Yes, it works fine on my GT.