RyanPerrella

Those are 4 cylinder cars, if John says they wont work, they wont work. I dont doubt him, look at the requirements of the ECU for a SAAB with 4 cylinders and which may or may not have a turbo and the requirements for the V8 porsche. Seems simple to me, and i dont know a damn thing about electronics, but i can assume they dont work just based on their original use. The Porsche needs to driev 8 injectors, take input from 2 knock sensors on and on. OE ECU's are built specific to a platform, and typically and reasonably dont include things that arent used in the car. So why would they have 8 injector "whatevers" when the car that they are supplying the ECU for has only 4?

backnblack

If you want to know a little more about this study the wiring diagram in the 928 manuals and contact Alan in the Arizona gang he know allot about the LH / EZK . Good luck I've been down that road and if I have the cash I would just buy the shark tunner

Regards
Matt

FlyingDog

The injectors are batch fired from 1 pin. The only way the number of injectors matter is the power required to drive them, which is relatively low on high-impedance injectors. The metal cased Bosch MAF used on LH 2.2 SAABs (84-90) is reputed to have the same electronics and hotwire as a 928 MAF including the idle mixture pot not present on most MAFS. The Temp II sensor is the same. All mainstream Bosch O2 sensors follow the same voltage curve, plus the car can be run open loop. EZF does not have knock and the LH doesn't care whether or not the EZF/EZK has knock sensing.

Does anything else seem plainly obvious to you? Since you 'don't know a damn thing', I'm sure you can tell me what other input/output is required to run the engine.

Edited to add: Both are 25 pin, but I haven't checked to see if the pin-outs are identical. I'm not saying John is wrong, just that it makes sense that it could work.That's actually the point. The LH/EZF in a 1984 Euro S is not sharktunable. You can swap in 85-86 LH and EZF to make it work, but they are far more expensive and less plentiful. I was looking for a way to increase the supply of usable/tunable parts.

borland

FD,

Maybe you can figure it out.... here's the schematic for the 928 LH...

http://www.928s4.com/lh/928_lh5.pdf

and the EPROM binary files...

http://www.928s4.com/lh/lh_homepage.htm

RyanPerrella

heres an idea

buy one for $100 and open them up and see what you find. I have said a million times i dont know about electronics, thats like Mandarin to me. But If John Speake tells me something relating to ECU's and engine electronics, I listen. Also he is not the type to point you in the wrong direction because he dosen't end up making a buck. I think he has been a huge help to 928's and i think all his business stemmed from his own interest in making his car better, or repairing it. I am thankful we have a guy with his knowledge doing R&D and then providing us with the fruits of that labor.

$100 isnt allot to spend as an investment if you really think it can save you x thousands of dollars. Give it a shot. If it dosent work you can just resell the ECU on Ebay and probably get most of what you spent on it back.

John Speake

Here's a comparison of a Volvo 740/760 LH and a Porsche 928 LH.

I have removed the 25 way connector from the Volvo unit on the right, but other than that it is untouched.

borland

That's interesting, no hybrid circuit on either one... I though they looked like this, with the hybrid...

John Speake

That's because that a Volvo or Saab late '80's LH2.4 with a 35 pin conenctor.

The pictures I sent were of LH2.2 with 25 way connector.....

FlyingDog

borland, that is an LH 2.4.

Here is another version of the Volvo 0 280 000 541 LH 2.2 which looks a lot like the 928 LH 2.2 shown in John's pic.

http://forums.turbobricks.com/showthread.php?t=84817
Other possible LH 2.2:

John Speake

That one does look very similar....... the ones I have seen were 505 and 541. But there were obviously several iterations of 541.

PorKen

I was at the U-Pull yard today, looking for connectors to hook up my KnockLite, and I came across a '87 760. I opened up the LH case, and it looked very similar to my rev. 04 board, so I bought it. (928 rev. 3, 4 boards.) The Volvo board is '0 280 001 510', and has a removeable EPROM. (eBay shows this box for '87-'90 760, 780)

On further inspection, however, although all the main chips are the same, there are differences in resistors, and capacitors. I stuck a 928 chip in it, and it starts, but does not run unless you give it some pedal, and then it runs roughly.

I also found a couple 740s. They have simpler boards, and no metal catch on the connector. Another 760, an '89, had a soldered EPROM.

The Volvo brains can be had for ~$30. If you were so inclined, and had lots of free time, you might be able to convert one?

John Speake

I'm not sure about the one in your picture, Ken. There are some significant component variations.

The one that Matt shows in his last mail looks a better bet.

PorKen

John,

Those are both 928 boards, top rev. 03, bottom rev. 04.

The 760 board I have is identical to a 04, but with different resistors, as much as I can tell. Too much work for me, so the 760 board is destined to be a passthrough donor (I cut the harness connector out with it).

BTW, on a show about airplane black boxes, they showed a fella removing memory chips from damaged boards with a heat gun (well, a fancy machine that was essentially a heat gun). I'm going to try using my heat gun, with a focusing attachment, to remove the connector.

karl ruiter

In theory, as long as the bare circuit boards are the same, the components could be changed. But if you look at the boards you will notice a shine to them. That is from a conformal coat (like a clear coat of paint) that is placed on top of the boards after they are assembled and soldered. Boards which have been treated this way are much more immune to moisture and other contamination, but they are almost impossible to rework.

69gaugeman

just subscribing, please carry on.