FUEL PUMP RFI ( ham radio related)

not sure.....

 

I did just clamp 7
Ferrites onto the harness that leaves the FP ecm Amd that didn’t help, but to be expected, it’s not the source point of the RFI.
They did use a shielded cable from the ECU back to the pump, but it’s either not enough of a shield or they did that for ingress rather than egress ( which should not matter) but leads me to believe the pump it’s self could be the issue and it’s not radiating from the wiring. I fired up the truck and checked same frequency on my house setup , and none of my
Antennas are picking it up that way, so it’s definitely close up radiation.

either way, I’m at a stand still until I can make a pig tail with a few turns on it and plug it into the pump harness at the pump it’s self.
Or just say eff it, and not work HF mobile….

Although now I kinda want to unfuck this as it has my focused attention…..

 

Sounds like it’s the actual pump and not signal related. When you give it some gas does the interfering signal change at all?

 

Unfortunately I have not been able to get a good enough resolution on the spectrum analyzers I have at my disposal to really see any significant changes based on RPM or load/demand

 

Now I’m wondering if there’s a way to effectively shield the pump, but that seems unlikely with where it’s located.

 

I can see if I have any of the issues in a few. I haven’t noticed them too much, but I might be able to grab my nano vna and see if I have a way to connect to it and sniff the fuel pump.

 

I’ve been looking at pictures of them online. I’ve seen two types of replacements. Whole assemblies or just the physical pump it’s self.

looking at the actual pump , it has a metal case, which COULD have some braiding soldered into and brought out and bonded to the frame.

 

Not sure the VNA would show the spectrum like the tiny SA would though.
If you have a hand held SW RCVR , that would basically be the same audio wise


The FT-891’s do not have an IF tap to be able to use an RSP to see it on the waterfall , aka pan adapter.
I do have one of those antenna splitters ( taps) to feed to a pan adapter using the RF of the main antenna but I really don’t feel like ripping that out of the shack and undoing that from my loop I use for SW listening outside of my resonant antennas

 

I bet this wouldn’t be an issue with a metal fuel tank , but being it’s plastic , nothing shielding that pump inside there.

 

The plastic tank is why I was wondering if there was a way to shield the pump, or maybe even wrap the tank. But that might be more work than it is worth. I'm charging my laptop now to try to use my SDR to see if my truck has the same issues. I've never noticed it but I also only run an FTM-400 in the truck, never used my 891 with the truck.

 

I have no issues with VHF or UHF, not that I used it often, but when I do , no hash or trash. I may reach out to my local stealer on Tuesday and hit them up. But without there being any TSB's about it, their answer is going to parrot what corporate said.... ( its not a factory installed item, not our problem) and i certainly do not want to throw diagnostic money at the dealer for them to say " all systems pass".

 

I don't blame you there. I' probably start with winding a toroid, that'll be the cheapest way to start. I haven't personally seen a taco fuel pump, but there might be a way to ground the body of the pump to the truck?

 

Oooooh, what if you wind the antenna cable through a toroid or use a line isolator at the radio?

 

The pump its self look to have a metal case , somehow that could have some flat braided bonding strapping then run that out through and bond to the frame. Not sure exactally though. Probably one of those things i wouldnt know until i dropped the tanlk , pulled the pump housing and studied it.....


Found these pics on another thread.

https://www.tacomaworld.com/threads/3rd-gen-fuel-filter-and-low-pressure-pump-system.687567/


I could probably ground strap and use a hose clamp to connect it around the pump its self..

what I dont know is how to pass the ground strap through the assembled unit ......

https://twstatic.net/attachments/8e220bb6-f461-4a51-a0a2-84bafed577a3-jpg.4174095/


https://twstatic.net/attachments/4-jpg.4174002/

 

There's got to be enough room in there to pass a small ground strap, I don't imagine it would have to be huge. But you could start with getting a couple large ferrite cores and doing like 7-10 passes through them of the feed line near the radio.

 

I already have a large mix 31 roid with about 15 turns at the radios antenna connection point. Also have ferrites on the power cable directly at the radio harness along with a huge 50amp " conditioner" up at the battery feed .... None of this is entering through the DC power source. All antenna pickup

 

I'm just spitballing ideas of how to not fuck with the fuel pump, but block the rfi from reaching the radio that's being picked up at the antenna.

 

I kind of remember Ford trucks having RFI issues and the fix was a metal shield around the pump. The ARRL has some info on fuel pump noise have a look there you are not alone. Have you contacted Toyota? Another possibility is a pump on the way out. See where this gets you arrl.org/auto-manufacturer-s-policies

 

I got ya… believe me, I’ve been through all this two years ago when I did the install. I kinda ignored it and limited my mobile ops. Was on vacation last week and had it on for the trip and then I remembered why I keep it off most of the time. But it’s now back on my radar.

 

Been in that page for the ARRL, and most of their info is older vehicles that use standard 12v constant on with return lines. Nothing really get into this new fangled eco friendly Voodo BS.

I did reach out to cooperate last year at one point in time, the call centers response was being it’s not factory installed, it’s not our problem. I could never get beyond that to get any answers from someone who isn’t reading from a pre written flow chart.


As for the pump going out. It’s been this way since I purchased in ‘19. I’d figure it it was going out, it would have by now