sniper wiring RF and temp sender.

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clementine

clementine

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Hello FABO!
Im wiring......and wiring....and....

I called Holley and they said I could extend the two wires for the temp sensor that leads to the front of block right next to the dist. There is a RF ground that runs alongside of the two wires (purple and green) that terminates a couple inches before the plug for the sensor. I am using the same size wire and stripped another wire for to extend the RF cable to duplicate the RF wire. Also, the wires are wrapped in a foil (faraday ish) that I plan on using HVAC foil tape to duplicate (should I just use aluminum foil?). The thick black sheilding that is on the outside is thicker than heat shrink so I am still figuring out what to duplicate that with. I think these wires are sensitive to RF (obviously) but wonder if the extra resistance from lengthening will mess with the sniper AND am I doing all the things that I can to make this a successful splice. I am soldering all connections and using heat shrink. ALSO, for that 1.5" where the RF is spliced will that short bit of shielding be a problem.....clear as mud? Good. I can get pics tonight. At the mines right now.

Have I told you guys how much you rock lately?

FABO RULES!

Side caviot.....I also extended the dist wires.....but i dont think they are as sensitive to all the things.....but feel free to weigh in. Again with the soldering/heat shrink and same size wires
 
It is likely that the Faraday shield is the key. You can buy short lengths of various shielded cable on egag. The resistance should not affect it as it's a low current circuit Normally, don't ground the shield at the sensor end but only at the opposite end, and "dress" the cable close to engine block / ground and of course away from high current wiring or ignition wiring.

There's been 3/4 times "back" that I've "made" a shielded cable by stripping a scrap of coax--such as used for transmitting, CB/ amateur/ 2 way etc. This takes work. Carefully slit and remove the jacket, "bunch" the shield up a bit by pushing it together down the center conductor, and slip it off. You can "make it larger" by bunching and get it over the subject cable

On a side story, I once had to do so with some Motorola adapter cables for dispatch consoles (Centralink/ Centracom) to the headset jacks. This was during the time that CRT displays were becoming much larger, and were "buzzing" in the mike / headset wiring. "I was the hero" for a day or two over that, as the cabling was proprietary and would have been difficult to replace
 
67Dart273 said:
You can "make it larger" by bunching and get it over the subject cable
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The original braided cable just ran next to the wires and was enclosed with foil. Since I have made the splices, but not enclosed in foil yet...do you think I will be ok with splicing the home made stripped wire next to the wires, all bundles with foil? Or is it recommended to do the "bunch" method and wrap with foil? Is the HVAC foil tape better than household aluminum foil? The original is very thin 'crepe' style....almost like a wrapping paper or a pinata streamers...to paint a picture.

Thanks all for replying. I know this is tick tacky crap but Id like to do it once.
 
I cannot answer your questions on foil. Frankly, even though it's used "a lot" I've never been a big fan. They use both shield and foil on TV / satellite coax, so I don't know
 
Temp sensor should not be affected by RF as it’s measuring resistance. Crank, cam, distributor (if running one) should all be your concerns. Anything that generates a “signal” in voltage through the use of a mag sensor is susceptible to RF. Hall effect sensors are also just not as sensitive. A good rule of thumb is just keep wiring away from anything high tension, ie spark plug wires and coil wiring. And when you think you have everything grounded, add more grounds. And then add a few more.
 
TT5.9mag said:
Temp sensor should not be affected by RF as it’s measuring resistance. Crank, cam, distributor (if running one) should all be your concerns. Anything that generates a “signal” in voltage through the use of a mag sensor is susceptible to RF. Hall effect sensors are also just not as sensitive. A good rule of thumb is just keep wiring away from anything high tension, ie spark plug wires and coil wiring. And when you think you have everything grounded, add more grounds. And then add a few more.
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The dist leads did not have the RF sheilding. I will follow the advice and keep triggered or sensor wires away from HIGH VOLTAGE! (done dirt cheap!)

thanks! Ill still probably post some pictures of my progress to give thanks to the gods of information.
 
The big big big problem I have run in to is a sensor sending or actually failing to continue to send a signal to the ECU because of RF. When this happens the system thinks it is back at start up. Resets, and in my case dies. Some will reset so fast that the motor doesn't actually die. This is easy to determine because your graph will show all the resets.

I have mine down to dying because of the loss of a fuel pump signal which causes a zero fuel pressure condition. I think once I figure that out I'll be clear of the major headaches and can finally move forward.

The other problem is that even though I keep trying (wont give up) to move in to the computer/electronic age. I think I'm forever stuck in anolog.
 
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Well if you remember, shout out what the diagnosis/solution is so if I have to RF shield more wires I will.
 
RealWing said:
This is your best go-to place for Sniper questions and problems. Many helpful and knowledgeable people there. Jim
Sniper EFI
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Just flipping through a few of the RFI shielding threads and wow!....I hope I havent bit off more than I can chew. Ill be dilegent and house the wires carefully. They are speaking of making sure the air cleaner is isolated from the throttle body and that sort of thing.....you are right....a lot of info there for sure!

Thanks Jim!
 
I'm here to tell you. All this shielding RFI EMI is frustrating as anything you'll deal with automotive. Holley knows this is an issue and is doing nothing to solve the issue from a manufacturing stand point. I'm really looking forward to all the perks of efi when I finally get there but till then. Holley can kiss my *** before they get another dime.
 
Well keep in mind that every DIY does things a bit differently. The auto manufacturers spent millions R&D systems to bet them fairly RFI proof and some of them STILL arent--when you start adding 2 way and other specialized add on equipment.
 
Blind Squirrel said:
I'm here to tell you. All this shielding RFI EMI is frustrating as anything you'll deal with automotive. Holley knows this is an issue and is doing nothing to solve the issue from a manufacturing stand point. I'm really looking forward to all the perks of efi when I finally get there but till then. Holley can kiss my *** before they get another dime.
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I read all these posts on efi problems, I have a fast 2.0 , on my 505 , but have never had any of these problems , but dont want any , never hurts to learn.
 
I have the ProFlo4 system on my car ECU mounted under the dash and don’t have any of these RF issues. Bluetooth connectivity is good. I don’t understand the point in going to EFI if you’re going to continue to run a wet manifold when better options exist. Also all of the electronics are mounted in the worst possible place where they are exposed to their biggest enemy HEAT.

Just to be fair I did have issues with rotor phasing but once that was sorted out it’s perfect.
 
Here are some pictures of the original shielding and my solution. I will continue the metal tape along wire. It will contact the original shielding at the splice (not shown as its under the tape) so is this sufficient grounding? @RealWing Jim? I question if the shielding is grounded because it in its stock form, just runs into The back of The throttle body (into the ECM?) With a gasket separating The TB to The intake, it must get grounded elsewhere? Would it make sense to make a little pigtail ground near the splice area that contacts the shield? The bare wire running adjacent to the others is spliced to the braided wire and terminates about 2" before sender/ plug.

Not trying to make a mountain out of a mole hill here, i just know that i will probably have some startup issues and I'm trying to eliminate as many things as i can so i have less to track down later.

Thanks ladies and germs

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clementine said:
I question if the shielding is grounded because it in its stock form, just runs into The back of The throttle body (into the ECM?) With a gasket separating The TB to The intake, it must get grounded elsewhere? Would it make sense to make a little pigtail ground near the splice area that contacts the shield?
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Easy to check, use an ohmeter. The gasket does not insulate it, because it's bolted to the intake with 4 fairly substantial bolts But that does not mean the shielding is connected, wouldn't THAT be a hoot? I've never fiddled with a Sniper can you "get into" it or is it sealed? If you can I would not hesitate to add pigtails as close as possible "practically" to the shielding
 
Mopar73340 said:
I have the ProFlo4 system on my car ECU mounted under the dash and don’t have any of these RF issues. Bluetooth connectivity is good. I don’t understand the point in going to EFI if you’re going to continue to run a wet manifold when better options exist. Also all of the electronics are mounted in the worst possible place where they are exposed to their biggest enemy HEAT.

Just to be fair I did have issues with rotor phasing but once that was sorted out it’s perfect.
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Agreed, there are better options, but i have it now and not having your experience, i feel like trying my best to make it work. Ill look up proflo though to check it out.
Thanks!

Edit: Not that Im really in the market, but Does Edelbrock make that system for a 383 (B)? Im seeing 413 and up RB.
 
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67Dart273 said:
can you "get into" it
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Not sure, but I believe its tucked into the float bowl area on these units. I have read some of the things guys have done like lining that cavity to faraday cage it and such. My thought is to get it installed as close to the instructions as possible. I am running battery in trunk and this issue with wires needing length are the big changes so far. I am fairly certain I ordered for a 383 BB, so why do they give you enough wire to run the dist wires across or under the intake? Seems like a hot area to choose. Anywho....Ill keep 'plugging' (get it? ....electrical?...ugh...horrible ..) along.

Thank you for the input. Half of this is mental and having the confidence to just put it together loosely and get the engine to fire, then troubleshoot.
 
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