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LH photos 900 1993

Hi,

Another share from Google Drive

https://drive.google.com/drive/folders/1F90TdZjUHJr4kFa4ZGrSb_Ti5VcoFWr_?usp=share_link


The jumpers are done because of damaged PTH holes on board. The PTH doesn't connect both sides of board AFTER soldering. Always check for continuity (the PTH) with multimeter AFTER soldering.

The small white "hybrid-analog" board is supposed to control over fuel pump relay activation. The 555 IC circuit was made to bypass this. This hybrid-analog board was problematic in old Porsche's LH ECU (circa year 1986) but not in Volvo's in my experience (my experience only covers 1994-1995 ECUs)

Here's the link about Porsche's issue:
https://www.jdsporsche.com/ECU-repair

Also included are photos of my spare 935 ECU from eBay made in Germany. It uses 3 resistor jumpers. But I'm currently using 935 ECU from Spain (original to car). I like original ECU better as engine running is smoother.

I can tell that the Germany ECU is older than Spain as its still using Philips ON823 as injector driver transistor (Darlington type). This part is already obsolete. Unobtainable from electronic stores. The Spain ECU is using Fairchild BDX53c driver transistor (also Darlington but non-obsolete). Maybe this one have better injector control.

Amarin






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New Wouldn't start [900][1993]
posted by  B.B. subscriber  on Thu Jun 8 14:01 CST 2023 >


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