FUEL PUMP RFI ( ham radio related)

Try this guys site for more bonding info: http://www.k0bg.com/wiring.html

 

Thanks, that's good info. I've got enough bonded at this point that anything further would taper into diminished return. If I had a garage to work in, I would have already pulled the bed off and done some work shielding the pump and controller.

This is a sample:

 

The problem with this plan is that vehicles are exempted from part 15 requirements. Most vehicles and automotive components are tested to CISPR 25 emission limits. Many vehicle manufacturers, including Toyota, have their own internal standards that are derived from CISPR 25. CISPR 25 radiated emission limits are not continuous across the entire frequency range. They are based on radio bands, but ignore amateur radio bands. So there are radiated and conducted emission limits in the FM broadcast band and CB band, but no limit at all in the 20 meter ham band. ECE Regulation 10 radiated emission limits start at 30 MHz, so no help for the HF ham bands there either.

 

I haven't messed with it since all of this. Im actually thinking about pulling the rig out and repurposing it for something else being i havnt turned it on since these postings

 

Reviving as some other gen 3 owners have had similar issues.

I still haven’t not addressed this further, but I do have to add some commercial radios, I may add the fuel pump issue to the list of things to do as well.

 

Clamp on ferrite chokes (radio end) will probably fit it.

 

Been there and done that, not enough room for clamp ons. Would need numerous turns on a toroid. Will have to replace fuel pump or add extension to harness to get about 7-10 turns to de-tune the radiation.

 

Try a different mix. I have clip on's on all 3 of my mobile radios no wraps just clipped on right at the radio. UHF to HF including 220. The HF has a toroid right at it's base and that's more so for the antenna motor.

 

Your mixes are rated for specific frequencies. Changing that up only changes the effective frequency range. I have no issues above 50 MHz, and all issues below there.

Mix 31 is what is needed for this scenario

A clamp on is equal to one turn. More turns,the better. To achieve the best results, would require a harness extension, in order to have more wraps. To be most effective, this would need to be as close to the radiator as possible , as further down the harness just creates a shift in resonance. Remember, the harness is acting as the radiating element ( the antenna )

 

In my truck, the interference overloads the front end directly. At least it does on HF, I don't use anything higher than 30mhz. I used the same setup, IC 7000 and ham sticks in my 2004 Tacoma for years without any issues.

 

Two completely different fuel systems. You would have a constant speed pump with a return line. The gen 3 uses a pulse width modulated fuel pump with no return.

 

I know. That's my point.

 

I ran into the same issue with my '24, which is technically a gen 4, but the symptoms and cause were the same. Unplug the pump's control module and it all goes away. Not at all surpring that they'd use the same stuff on the gen 4.

The control module on mine is in a different place, right inside the wheel well on the rear passenger side, so super easy to get to. I'm not quite car-savvy enough to go messing around with things too deeply, but I did put two clamp-ons each on the input and output wires to the module and that knocked the noise down from S9-S7 at the peaks. Figured I was on the right track so I bought a few of the giant 1.5" split ferrites from Palomar (the 1" ones are too small for that main harness) and stuck them on the main harness between the pump and the module. One didn't make a difference, but both of them together knocked the peaks down to an S3 at worst, sometimes less, and on occasion it jumps to 4 for a split second. On a really good day I might not even see a difference at all with it running. Not ideal (ideal would be S0 all the time obviously), but a hell of a lot more usable.

So I thought if 2 of those things made that much difference, then 1-2 more might just knock down the rest of it. Tried putting them in different places around where the harness splits to the pump and to the module. Never saw any improvement, and funny enough if I put one of them aft of the split to the control module it actually might have made things worse...it jumped up about 1 S level, but that could have just been coincidence with some other nearby noise source (or a super faint signal coming in). So not necessarily conclusive, but interesting.

I'm curious if the noise from the pump really is gone and now I'm hearing some other smaller noise source that was covered up by the pump before. If I am it manifests the same way as the pump noise did both in what it sounds like and when it happens. I'm planning to sweep around the truck when I have some time to see if whats left is coming from somewhere else, but at least for the time being it's very much improved.