Fuel Injection - KZN130

[gwh200]

I dont doubt what you say Gra, I'm just struggling with how it could generate an EM wave - particularly one of a high enough frequency. Maybe the pressure pulses act on impellers etc causing small currents in motor coils at the frequency of the pulses?

You cant have an EM wave without electrical current flow.

I realise that andy. But you can have a M wave without any electrical current flow .
The earthproducesits own magnetic feild by a postulated inner and outer core.
You can get an ectrical negative ground in a thunderstorm. There is a potential there, before any current flows. This is the potential that csusesfluidnoisr...apparently.

[TonyN]

I'm not familiar precisely how the Surf's injection system works, but normally the injectors are opened and closed by solenoids driven by very precise, fairly high current signals with very fast rise and fall times. The back EMF from the solenoid coils, and simply because fast rise times / square waves are very rich in harmonics and therefore broadband noise, tends to mean good possibility of radiated and conducted noise. Whether those solenoids are at the pump or at the injector itself matters not a jot.

All EFI systems suffer in this way to some extent. Obviously, mechanical injection doesn't.

The Surf dosn't, its still 'mechanically' pumped up to injectors individually, with a spinning disc that opens and shuts valves allowing fuel flow, the injectors open due to fuel pressure. The electrics control the timing advance and retard, depending on throttle position, air and fuel, etc...

There's a couple of resistors, a stepper motor, a couple of solonoids, and a RPM speed sensor, its nothing that exciting.

I'd say its more likely to be the Alt like you said at the start, take the drive belts off and try it again.

Our Surf makes interferance with my Belkin Ipod transmitter, but have never noticed any on CB or radio itself

[surfenstein]

To answer surfenstein:

The interference is certainly not alternator whine. Its not related to the road speed of the vehicle, but to how much the accelerator pedal is depressed and thus the amount of fuel being fed to the engine. There are some more details in the posts referenced originally..

ah right silly me....... so what your saying is the alternator cant possibly be connected to the engine in any possible way.funny i always though that the alternator was driven by a drive belt connected to the engine thus when you deppressed the throttle the engine rpm would go up thus the alternator being connected to the engine would spin faster aswell.how stupid of me.

[TonyN]

........Stroppy ramble.....

:snigger:

[Apache]

I realise that andy. But you can have a M wave without any electrical current flow .
The earthproducesits own magnetic feild by a postulated inner and outer core.
You can get an ectrical negative ground in a thunderstorm. There is a potential there, before any current flows. This is the potential that csusesfluidnoisr...apparently.

Thats gonna be low frequency then, which is backed up by your mention of AM radios. Think this guys radio is UHF.

[gwh200]

Must be his alternator then.

[surfenstein]

:snigger:

not stroppy........just making up for the loss of fatt.f

[gwh200]

not stroppy........just making up for the loss of fatt.f

I know what you mean mark....it's nice knowing your not gonna get your eyeballs licked by a coffin dweller.

[surfenstein]

I know what you mean mark....it's nice knowing your not gonna get your eyeballs licked by a coffin dweller.

isnt that illegal..................oh no im thinking of something else.

[gwh200]

isnt that illegal..................oh no im thinking of something else.

That's NEXT weekend....

[BUSHWHACKER]

Hey Vatch, seeing as you seem to be hovering on this thread, Lexus seats fit the Surf, but the mounts will need attention and you'll need to cut a hole in the roof to see out if you haven't got a sunroof.
And another thing, they are all electrically operated and even have their own ECU, so everything will need to be connected up as there is no manual adjustment to them, it's all motors!

[surfenstein]

Hey Vatch, seeing as you seem to be hovering on this thread, Lexus seats fit the Surf, but the mounts will need attention and you'll need to cut a hole in the roof to see out if you haven't got a sunroof.
And another thing, they are all electrically operated and even have their own ECU, so everything will need to be connected up as there is no manual adjustment to them, it's all motors!

do you know what vince its funny you should mention those seats,im hoping they will fit in my diahatsu,the roof line is a lot higher in that.is it just a case of a 12 volt feed to the ecu and are they fitted under the seats or remotely via a wiring harness else where in the vehicle.

[asgawth]

ah right silly me....... so what your saying is the alternator cant possibly be connected to the engine in any possible way.funny i always though that the alternator was driven by a drive belt connected to the engine thus when you deppressed the throttle the engine rpm would go up thus the alternator being connected to the engine would spin faster aswell.how stupid of me.

Clever cloggs. OK, so I was having a senior moment

What I was trying to say is that the interference is not alternator whine...

[BUSHWHACKER]

do you know what vince its funny you should mention those seats,im hoping they will fit in my diahatsu,the roof line is a lot higher in that.is it just a case of a 12 volt feed to the ecu and are they fitted under the seats or remotely via a wiring harness else where in the vehicle.

Yeah, the ECU is mounted under the driver's seat.
I can save all the plugs/sockets that go with them, plus I have Lexus wiring diagrams showing what goes where.

I think the ECU is mainly for seat position memory, there's two settings for each seat/driver.

[asgawth]

The Surf dosn't, its still 'mechanically' pumped up to injectors individually, with a spinning disc that opens and shuts valves allowing fuel flow, the injectors open due to fuel pressure. The electrics control the timing advance and retard, depending on throttle position, air and fuel, etc...

There's a couple of resistors, a stepper motor, a couple of solonoids, and a RPM speed sensor, its nothing that exciting.

I'd say its more likely to be the Alt like you said at the start, take the drive belts off and try it again.

Our Surf makes interferance with my Belkin Ipod transmitter, but have never noticed any on CB or radio itself

Thanks, for the info about the injection system Tony.

When I've got the accelerator depressed and the vehicle is doing, lets say, 30MPH I get lots of noise. If I then take my right-foot off the excelerator the interference drops aways to almost nothing very quickly. After a few seconds the noise starts again, albeit at a much lower level with my foot still off the pedal. As soon as I hit the pedal again for more power the noise starts again, returning to its previous level.

With these characteristics would you still suggest the alternator as the source? Its the fact that the interference returns by itself after a few seconds that makes me uncertain...

I'm happy for the advise and am willing to try things as this is driving me potty