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Injector impedance

Posted: Tue Apr 28, 2015 2:20 pm
by TopCat
Dear All
I thought I would share our findings/possible diagnosis on Herman's propensity to blow ECUs
x3 in 3 years!

We now have the best 061 rebuilt but the problem might be stemming from the Bosche injectors that have a peculiar part no (maybe Swiss) and have a v low impedance at 2 as opposed to the more normal 17
so we are going to change the injectors as well as ECU and keep my 074 as spare
will keep you posted

Re: Injector impedance

Posted: Tue Apr 28, 2015 3:41 pm
by Jeroen
A much lower impedance will defo put more strain on the transistors switching the injectors, this switching circuitry is a known weakpoint for many ECU's btw. Issues with wiring, impedance/resistance, oxidation inside the ECU, all common causes for ECU failures. On the 320iS I had the resistors on the ECU replaced by an updated version of the transistors as a preventive measure but these components will be different to yours I guess. Blown ECU's don't have to be ready for the scrap heap, it can be good to have them checked, perhaps they can be repaired.

But back to the likely cause, these injectors. Are these of the correct type as per Alpina spec? Do you have a part no? We could check with other Alpina owners perhaps, Arnold just moved his injectors around I believe. Perhaps the Alpina ECU is modified to deal with a different injector?

Oh and the Manx, wanna talk about it? :?

Re: Injector impedance

Posted: Tue Apr 28, 2015 4:19 pm
by TopCat
Ah yes - the Manx Classic- please post up my You Tubes fm Facebook?
Frantic here at work................!