Mobile noise in Toyoto Landcruiser

[VK5BC]

I have a Landcruiser 100 series 4l turbo diesel setup with an IC706 MK2 G using a Codan auto tune antenna mounted at rear of vehicle. All works fine except I cannot remove the engine noise which sounds like ignition noise but being a diesel I assume injector noise. It appears to be coming through the antenna, have tried with external battery and noise still exists. I've tried earthing the rear end of the exhaust but that does not make any difference. I tried removing the coax ant lead from the antenna and when I touch it to any part of the chassis the noise is there, it appears the chassis is alive with whatever is causing the noise.

Has anyone had a similar problem with HF radio in a 100 series turbo diesel Landcruiser and any suggestions on how to improve the problem, The radio is almost unusable while mobile unless strong signal.

Thanks

73's Brian
VK5BC

[VK3KGR]

Brian,

This is a common problem and there is plenty of information on various 4x4 forums. I think it comes from a computer in the side panel from memory.

[VK5PJ]

Hi Brian,
similar problem with a Holden Jackaroo back in 2006 before going on a holiday via West Aust. The Jackaroo also has the electronic injectors for the Diesel motor, while idling or traveling, the noise on 40M is S9 +20. If you let the vehicle glide (foot off the accelerator) the noise just stops (and you can hear signals) as the injectors have stopped firing in fuel.

Take the beast out for a drive, go down a hill and take you foot off the pedal, if it is caused by injectors the noise will stop being there if it is still there then it is some thing else. Other than that good luck, I researched it quite a bit and the only answers seemed to be radical surgery in my case, it might be better for you. Maybe ring a Toyota dealer and tell them the AM radio is noisy and see what they have to offer?

Regards,
Peter, vk5pj

[VK3AIF]

Hi Brian,

There was an article in the September 2007 AR magazine dealing with the noise in a 100 series Toyota it is on page 20 and almost a total cure was achieved. The claimed result was a reduction from 10/9 to about 1/2 an S point on 40 Metres.

Cheers

[VK3BQ]

If only the Old AR magazines were pdf'ed )

[VK3AIF]

I've got 1933 to 1939 A.R. mags as pdfs I have not seen a lot or references to Toyotas or electronic fuel injection in there though

[VK2HRX]

As pointed out there is loads of stuff available on this. Essentially you need to bond every piece of metal in the vehicle to every other piece. Doors, bonnet, panels etc etc.

Edit: and silence the injectors!

[VK3ALB]

The article speaks in general terms about curing noise in a 100 series diesel.

AR_Sep_2007.pdf

If only we had bookshelves to hold our information?

(216.7 KiB) Downloaded 369 times

[VK2JH]

HI Brian,

Just read your post as I was going out the door, so have to be brief. I have a 100 turbo diesel and suffered the same with my FT857D. There is an injector control box on the right side as you face the engine, just behind the large fuse box. BY "ferriting" all the leads coming out, a large improvement was noticed. The noise is still there, but very attenuated and one can actually hear and work stations.

Cheers,

John
VK2JH/VK4JHC
Mount Hallen 4312

[VK5ZLR]

Pull the wire off the engine oil pressure sender and see if the noise goes away.

[VK2JDS]

Put a 0.1uF cap to ground to quieten the oil pressure sender. Worked on my 1hz diesel. It doesn't have injector noise
The xyl's XTrail is computer controlled and its very noisy. I dare not touch it though.....