Id LH bosch jetronic part # 92861812304
#1
Race Car
Thread Starter
Id LH bosch jetronic part # 92861812304
Mike has loaned me his LH and upon opening it to use my 24 pin chip to test it for him I found it uses a 28 pin chip.
The white tag says: part # 92861812304 965
The Bosch jetronic tag "purple" says 928.618.123.04 part # 0 280 002 503.
So what does he have a 2.3 or 2.2 or a mystery unit .
The white tag says: part # 92861812304 965
The Bosch jetronic tag "purple" says 928.618.123.04 part # 0 280 002 503.
So what does he have a 2.3 or 2.2 or a mystery unit .
#3
Race Car
Thread Starter
Thats the one but the chip pins are not correct 28 pins vs normal 85-86 24 pin. I wonder if the cover may have been changed? My 85-86 has 24 pins I wonder about the newer 2.3.
#4
Inventor
Rennlist Member
Rennlist Member
LH2.2 has a 25 pin external connector. LH2.3 has a 35 pin.
The revision 4 boards have room for a 28 pin chip, but have a 24 installed. Maybe it's a rev. 5 board. Take a pic!
Rev. 3 and 4 boards, click for larger.
The revision 4 boards have room for a 28 pin chip, but have a 24 installed. Maybe it's a rev. 5 board. Take a pic!
Rev. 3 and 4 boards, click for larger.
#5
Race Car
Thread Starter
It looks like the bottom board except the socket is a full 28 pin. The chip is out and the first and last pins are usually B+ and ground respectively. If I insert a 24 pin chip looking at you board in that would mean I would need to place closer to the inside. I don't want to fry a chip due to the voltage being on the wrong pins.
#6
Race Car
I remember John Speake mentioning in another thread that the early '85 LH had 24pin chips, whereas the later ones had 28pin chips. Or maybe I read it in the Sharktuner manual, can't remember which.
Dan
'91 928GT S/C
Dan
'91 928GT S/C
#7
Rennlist Member
So if you use the chip that's in it already, how does your car run ?
I've not seen a Ver 5 board, but it sounds as though you need a "special" chip made in 27C256 format.
I've not seen a Ver 5 board, but it sounds as though you need a "special" chip made in 27C256 format.
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#8
Race Car
Thread Starter
As far as I know this Lh has never been tested, Firemed bought it for his flooded 86. He had a chip installed when he purchased it and I noticed the difference in pin outs. I am now using the chip that was in the Lh but never hooked it up. It is possible a chip was just placed in the socket or it actually worked but the placement is important as to not damage the chip.
#10
Race Car
I made a trim pot for a MAF on another car a few years back. It was real easy, just find the wire that sends the signal in the harness and splice a pot in there. May not want to do that on a 928 though
'91 928GT S/C
'91 928GT S/C
#12
Three Wheelin'
Join Date: Dec 2005
Location: In the boatyard installing the mast and engine, we don't need a crane, we harness the mesquito's! Yeah!
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Hey Mark,
I could just bring my motor and you can install the SC on it - of course I would need it back once you get it sorted out
I could just bring my motor and you can install the SC on it - of course I would need it back once you get it sorted out
#13
Man of many SIGs
Rennlist Member
Rennlist Member
Mike has loaned me his LH and upon opening it to use my 24 pin chip to test it for him I found it uses a 28 pin chip.
The white tag says: part # 92861812304 965
The Bosch jetronic tag "purple" says 928.618.123.04 part # 0 280 002 503.
So what does he have a 2.3 or 2.2 or a mystery unit .
The white tag says: part # 92861812304 965
The Bosch jetronic tag "purple" says 928.618.123.04 part # 0 280 002 503.
So what does he have a 2.3 or 2.2 or a mystery unit .
#14
Race Car
Thread Starter
This was Mikes board I tried to repair his the swap was a mistake.
I found that the difference between the 24 versus 28 pin is that the 24 pin keeps 8k of code 1/2 in the eprom 1/2 on the controller. The 28 pin keeps all the data on the eprom.
I found that the difference between the 24 versus 28 pin is that the 24 pin keeps 8k of code 1/2 in the eprom 1/2 on the controller. The 28 pin keeps all the data on the eprom.