The problem (I'm assuming they're linked) is apparent when cranking. Sometimes the ECU recognises the engine is turning and sometimes not.
Too recap the long saga thast been unfolding over the last couple of months, below is a massive thing I wrote on one of the other forums:
The battery is brand new, and I believe the ECU can take as low as 5v. The sensor is shielded as per standard, and earthed at one end only. The one end only thing is the only advice I’ve ever read, in fact I think I’ve read in Dave walkers section in the mag that it shouldn’t be earthed at both ends. I’m not wishing to sound ungrateful just what I’ve read (I’m in way over my head now anyway).
There is a lot more in previous posts about the fault (although you’ve got to look way back, its been going on for a while). But the basics are as follows:
I’ve checked and checked the polarity, to the point where I made a connector that reversed the polarity of signal wires, and its definitely wired up correctly.
There are two symptoms, of what I imagine are the same problem.
Firstly there is a two colour LED on the ECU, red for no CPS signal (or not recognized) and green for CPS signal ok (when green the ECU then starts dishing out sparks and fuel). When cranking the engine to start, the LED goes green in less that a second (as it should), but sometimes it just stays red. If its stays red for more than a few seconds you can guarantee it’ll just stay red indefinitely. Stop spinning the engine and start again, and it’ll go green (and start of course). It doesn’t matter if the ECU is left powered on between tries, or switched off, it seems unrelated. This is not a major issue but might be embarrassing when starting the car to show folk .
The second issue (and more importantly), is while the engine is running the LED momentarily goes red (quarter of a second maybe), the engine begins to die then picks up to idle again. The “hiccup” happened quite randomly, and without warning, something like every 30 seconds. It happens regardless of throttle position and revs.
The fault is “the ECU is loosing the CPS signal momentarily (or indefinatley when cranking). I’m not sure why.
Obviously I can’t try much disconnecting with the engine still running and I’m working on the assumption that the two symptoms are one problem, I’ve bee trying to fix the problem and testing the success (or lack of) by cranking only and observing the LED.
There have been numerous emails between the manufacture and myself, with many a suggestion tried, bit the main theme so far has been get the earthing right and make sure its not picking up any noise.
Its no got to the point where nothing at all is running accept the starter motor, with one massive thick lead to the pos on the motor, and the block earthed via the chassis back to the battery in the back of the car.
And the ECU with a wire powering it straight from the battery pos and the 3 ECU earths running separately all the way back to the batter neg.
There can be no earthing issues, none of the sensors are connected to the ECU none are connected to earth, they’re just parts sitting in the car. The cars loom is dead I’ve been turning the engine by shorting the pos on the starter the start solenoid with a spanner. None of which is anywhere near the ECU or any of its wiring.
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Topic: Scimitar MV6 (Read 77209 times)