AFM / Resister pack earthing
Discussion
Thanks, that is what i thought but then :-
In the "Tuning Rover V8" book it states "Other points to note include the mounting of the AFM, which in both systems is mounted on rubber bushes to isolate it electically from the vehicle body/chassis"
They are talking metal bodied cars, but that would imply it should not be earthed then ?
In the "Tuning Rover V8" book it states "Other points to note include the mounting of the AFM, which in both systems is mounted on rubber bushes to isolate it electically from the vehicle body/chassis"
They are talking metal bodied cars, but that would imply it should not be earthed then ?
Time for HJ2 to post methinks. According to the schematic the earthing is from the loom back to the ECU through the AFM multiplug (from memory). So the extra earth strap might be overkill and/or couple noise into this sensitive area of the circuitry.
Also there's an earth strap from the resistor pack to the AFM (as I recall) so I wonder if this is even worse? We may be coupling injector pulses (at a low level) back into the AFM input.
Also there's an earth strap from the resistor pack to the AFM (as I recall) so I wonder if this is even worse? We may be coupling injector pulses (at a low level) back into the AFM input.
Nick, did you get the 450se running sorted. Interested to hear what the fault was rather than the suggestions of changing everything for different control systems.
I remember many years ago talking to a guy at a TVR Brooklands event who had a 450se who explained that it was a total nightmare getting it to run right.He was told that the control system was totally on the limits.
I remember many years ago talking to a guy at a TVR Brooklands event who had a 450se who explained that it was a total nightmare getting it to run right.He was told that the control system was totally on the limits.
not at present, only starts full thottle and then runs like a bag of nails in a washing machine, and does not idle, no idea how many are firing. So a bit stuck really, if TVRpower, TVR central and RT racing cannot fix it...can I ???
I have gone back to basics, the earth wire was broken going up to the pack and was stuffed behind the afm which was not earthed either, well not by a strap anyway
I was told if multiple cylinders missing the pack was a good bet. I have a flapper setup complete and also now brought a Griff 500 HC hot wire setup.
The plenum on the Griff is standard bore, thought it might be bigger so bit disapointed really and now reluntant to fit it.
So do i refresh with the s/h flapper system, stick on the hotwire, then megasquirt, carb it - i really have not a clue and of course i have a 400SE still sat here as well with the rear brakes in bits and me wondering which bits of the chassis i can live without to get access.
I have gone back to basics, the earth wire was broken going up to the pack and was stuffed behind the afm which was not earthed either, well not by a strap anyway
I was told if multiple cylinders missing the pack was a good bet. I have a flapper setup complete and also now brought a Griff 500 HC hot wire setup.
The plenum on the Griff is standard bore, thought it might be bigger so bit disapointed really and now reluntant to fit it.
So do i refresh with the s/h flapper system, stick on the hotwire, then megasquirt, carb it - i really have not a clue and of course i have a 400SE still sat here as well with the rear brakes in bits and me wondering which bits of the chassis i can live without to get access.
The resistor pack doesn't 'need' an earth as there's nothing inside that requires one. All the resistors are in series with the injectors (ie at 12v, more or less).
Similarly and as Adam says, the AFM gets its earth through the loom.
One possible reason I could see for the AFM being earthed would be to reduce static build-up caused by air flowing through it whilst it's isolated from chassis via the rubber mounts (same thing happens on sandblast cabinets, the airflow causes static charge on the steelwork).
More than likely it's down to someone at the factory who didn't know why they were doing it, just that they were told to
Similarly and as Adam says, the AFM gets its earth through the loom.
One possible reason I could see for the AFM being earthed would be to reduce static build-up caused by air flowing through it whilst it's isolated from chassis via the rubber mounts (same thing happens on sandblast cabinets, the airflow causes static charge on the steelwork).
More than likely it's down to someone at the factory who didn't know why they were doing it, just that they were told to
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