BIG_MVS wrote: Sent it to JohnC who fully tested it and replaced a few diodes? Still the same when fitted.
As Martin has mentioned me in connection with this fault, let me follow up on my examination of the ECU.
I was pleasantly surprised by the build quality of the ECU. Certainly not what I expected knowing the "quality .... not" of the electrics in these Alps ....... it was excellent with no sign of dry joints or solder cracks. I did change four electrolytic capacitors as a matter of course, remembering under normal operating conditions, they have a life of approx 15 years. The originals had a operating temperature of 105 degrees, and I replaced them with identical values, but with operating temperatures of 125 degrees just to be on the safe side.
It did not make any difference at all ..... when reinstalled in Martins 610, it still cut out.
However, I did make a suggestion that, as others had suggested, the ECU was getting overheated, so I did suggest a test in order to possibly prove or disprove my theory.
I still have the PM I sent to Martin asking him if he would like to check my theory out, but to date he has not come back to me on this, and I await his report. I also have discussed this test with others, but to date no one has come back to me.
I still think it is worth the test, so I am sure Martin won't mind my copying my PM to him, below.
Basically the check is to run the ECU in cool air as opposed to the electronics being cooped up in a sealed box with no ventilation.
A couple of things to note.
The reason the 610 engine cuts out when hot (never when cold) is because the fuel pump stops working.
The fuel pump relay is controlled by the ECU when the engine starts to turn by cranking or engine running.
The reason this happens in this way is that the ECU uses the crank sensors pulses to firstly trigger the ignition, and also control the circuit to energize the the fuel pump relay.
Remember, when the fuel pump relay is forced on with the earth link, the engine runs perfectly thus ruling out any other external faults to the ECU.
Also the ECU is in control of the priming of the fuel pump, and temporally energizes the fuel pump relay for a few seconds when the ign is switched on.
Here is my PM to Martin.
Hi Martin,
Thanks for the update on your ECU, it was however, something we rather expected after I had had a good inspection of your ECU, but it does prove that the electrolytic capacitors were not the cause, neither was there any dry/cracked joints.
Now having had a good look at the ECU, my mind is turning to the positioning of the ECU and its proximity to the turbo. It could well be something that others have suggested that it is due to sheer overheating of the ECU for the cutting out. Also remember that it does also happen to the GTA turbo's but perhaps not to such an extent.
Don't worry, I am not going to ask you to do anything .... yet, just a bit of info for me please, As you know I am a bit tenacious when it comes to fault finding.
Now remember I have not seen in the flesh one of these installations, so .... perhaps you could tell me if it would be possible to detach the whole ECU plus relay plate, and, if the wiring would allow, could it be folded down, so to speak, and laid on the gearbox housing, ie:- between the two rear seats. In other words effectively removing it from the turbo's heat source.
My idea is that If that were possible, I also noted that the ECU's removable cover faces the bulkhead, and if folded down on the gearbox cover, that ECU cover would be upper most, and could be removed.
Now if that all were possible, the circuit board & components would not get as hot as they do when the ECU has its cover on with no ventilation.
I think you said that you work in IT, so you know that most circuit boards in computers have fan assisted cooling, and in all fairness, if you think of the 610's ECU boxed with no ventalitaion close to the turbo, in my view, just like others have said, the ECU could well be overheating.
So, at the moment my question is, ... would it be possible to "fold down" the ECU on to the gearbox housing, ie, do you think the wiring would allow such a move.
I am not asking you to do it, but having experience in changing these ECU's, do you think this is possible?
I have most probably gone into more detail than I needed to, but I thought it might help to see which way my mind was thinking.
So, I am afraid it is back to you, but I will be at Goodwood in August so I will be able to see an installation in a 610 for myself, in the mean time, your view on this would be appreciated,Anyone interested in doing this test ? Any questions, please don't hesitate to to contact me.
John
1990 GTA Atmo, 2003 Jaguar X type 2.5SE Auto, 2018 Kia Picanto GT-Line-S 1.25
