View Full Version : Sniper RFi/EMI interference
nick7405
06-04-2023, 03:35 PM
Hey everybody. Wanted to share some knowledge and have it hopefully help out another member in the future. I have been struggling with RFi interference and finally got it narrowed it down to one of the wires coming out of the sniper unit. Specifically the one for the coolant temperature sensor. Will order some faraday cable loom stuff and wrap all the sniper wires in it. But this aluminum foil and originally had everything covered including alternator and distributor and coil and all wires. Slowly took away a piece and see if it changed and used process elimination with what was being affected or had a change. 185384
I actually also swapped the connector for the other cts for the gauge and also found that rerouting the loom to the other side of the intake also removed the issue however found out that sensor had a different voltage/temp reading. It was trading 230 at 180
nick7405
06-04-2023, 03:42 PM
Sorry for grammar! Hate posting on the phone
nick7405
06-05-2023, 07:04 AM
Never mind it’s back :confused:
Geoff H
06-05-2023, 07:22 AM
Thanks for posting. I like you approach instead of throwing everything at it all at once. I have wrapped a few of the wires in faraday tape but did not think about the senders. I don't seem to have any issues anymore, and after the remote tune it runs better than ever.
Geoff
nick7405
06-05-2023, 08:00 AM
Who did your remote tune
weendoggy
06-05-2023, 08:19 AM
Easy check just to make sure the system isn't going a-foul of operation, check the Air Temp and CTS before starting in the morning. They should be within 3° or so of each other. If the CTS is way off, you need to change that first. It will effect the tune a lot. Not saying this is your issue, but just another thing to eliminate from chasing a problem.
Blitzboy54
06-05-2023, 09:08 AM
What symptoms did you correct with this? What was the engine doing ?
Have you de-pinned any unused wires and plugged the connector per Holley's recommendation? Any unused wires or openings in the connectors can act like antennae.
https://www.summitracing.com/parts/hly-567-101?seid=srese1&ppckw=pmax-tools&gclid=Cj0KCQjwj_ajBhCqARIsAA37s0w9dofwyzyKzBC7S87J ZO78AmEIc96WGViPi8l2GIz69yPcBOIGqvsaAoOxEALw_wcB
Geoff H
06-05-2023, 09:52 AM
Who did your remote tune
This thread has a few options. https://thefactoryfiveforum.com/showthread.php?46243-Tuning-Holley-Sniper&highlight=remote
I used Andrew at projectgattago@gmail.com.
nick7405
06-05-2023, 01:07 PM
What symptoms did you correct with this? What was the engine doing ?
Two symptoms, the rpm indication will jump irrationally or all the sensors will go out for a split second which I guess is the ecu resetting. Either case the car stumbles and spitters
nick7405
06-05-2023, 01:07 PM
Have you de-pinned any unused wires and plugged the connector per Holley's recommendation? Any unused wires or openings in the connectors can act like antennae.
https://www.summitracing.com/parts/hly-567-101?seid=srese1&ppckw=pmax-tools&gclid=Cj0KCQjwj_ajBhCqARIsAA37s0w9dofwyzyKzBC7S87J ZO78AmEIc96WGViPi8l2GIz69yPcBOIGqvsaAoOxEALw_wcB
Depinned yes, plugged…idk. Will check tonight
nick7405
06-05-2023, 02:54 PM
Have you de-pinned any unused wires and plugged the connector per Holley's recommendation? Any unused wires or openings in the connectors can act like antennae.
https://www.summitracing.com/parts/hly-567-101?seid=srese1&ppckw=pmax-tools&gclid=Cj0KCQjwj_ajBhCqARIsAA37s0w9dofwyzyKzBC7S87J ZO78AmEIc96WGViPi8l2GIz69yPcBOIGqvsaAoOxEALw_wcB
No they’re not plugged. I know the yellow wire in the 7pin connector isn’t plugged which is active. So I need to plug all the optional ones????
No they’re not plugged. I know the yellow wire in the 7pin connector isn’t plugged which is active. So I need to plug all the optional ones????
It is recommended that any de-pinned wire have a plug in the connector. The exposed wire in the connector can create noise and the connector itself can act like a waveguide.
Dave
narly1
06-05-2023, 03:16 PM
How about trying a ferrite bead or toroidal core on the temp sensor lead?
Earl
nick7405
06-05-2023, 03:37 PM
How about trying a ferrite bead or toroidal core on the temp sensor lead?
Earl
What is that??
narly1
06-05-2023, 08:24 PM
What is that??
Ferrite beads and toroidal cores are electronic components. They are used to filter out high frequency electrical noise (aka electrical interference). Wikipedia does a way better job of explaining what they are and how to use them than I can, LOL.
https://en.wikipedia.org/wiki/Ferrite_bead
https://en.wikipedia.org/wiki/Toroidal_inductors_and_transformers
A toroidal core can do the same duty as a ferrite bead by looping the subject wire conductor (temp sensor lead) through it a few times before going on it's merry way to your instrument panel.
They are both cheap and easy options to try to fix your tach reading erratic issue. ~ $1.
Earl