View Full Version : Gauges not working!
I just started my car for the first time yesterday. I have 347 with sniper efi and hyperspark ignition system. the car runs well.
I can't get a couple gauges to work though. Any help would be very appreciated. I probed all the wires with the ignition on.
They all show power and ground and all the lights work too. I double checked everything and its all wired per the manual. It's almost like all the signal wires are the culprits, but i cant believe there would be so many gauges not working....
1. The tach does not show any movement at all. It's stuck on 0 rpm. The sniper efi shows the rpms correctly though. I have the dark brown wire from the efi to the signal wire directly on this one.
2. the fuel gauge works well
3. the voltmeter works well.
4. The oil pressure is pinged at 100 psi. and doesnt drop until the ignition goes off back to 0 psi
5. The water temp pings at 250 degrees. I know this is wrong obviously as the efi has the car running about 190 constantly with the fans working.
thanks,
tony
For the tach, don't use the tach wire from the Sniper, use the RF tach wire that runs to the coil. The gauges that are pegged sound like a bad ground connection.
It's the hyperspark ignition system so all the wiring runs through the efi. The manual for it says to use the tach output(dark brown wire) . As for the sensors could Teflon tape impede the ground signal. What about arp thread sealer? Maybe it loses ground that way...
It's the hyperspark ignition system so all the wiring runs through the efi. The manual for it says to use the tach output(dark brown wire) . As for the sensors could Teflon tape impede the ground signal. What about arp thread sealer? Maybe it loses ground that way...
Trust me on this one. Your tach gauge will work if you use the RF tach wire to the coil. I assume you have gauges provided by FFR; either Speedhut or Autolite?
JimLev
08-17-2019, 08:45 PM
Think he meant Autometer gauges.
No, Teflon tape won't effect the grounding of the sensors, when they are screwed into the engine most of it will be cut away by the threads.
Think he meant Autometer gauges.
No, Teflon tape won't effect the grounding of the sensors, when they are screwed into the engine most of it will be cut away by the threads.
Yep -- Had spark plugs on the brain the last few days.
I did some probing with the multimeter today. I probed at the water temp gauge and got 100 ohm. Also did the same thing at the oil pressure (120 ohm). i then probed at the signal right at the gauges themselves. Got the same numbers with the ignition off. Now when I turn the ignition on, the ohms go to zero. I dont know enough about wiring to know if that's correct or not?
Ohms going to zero = no resistance = short circuit in your wiring somewhere. Check your wiring for those non-functioning gauges. Make sure you have them wired to the proper leads and didn't cross something when you made your connections.
FF33rod
08-18-2019, 05:33 PM
Tony,
What sensors did you use? You have to use the ones supplied with the gauges. I initially tried using a mustang oil pressure sender and had the same result as you. Turns out it was a switch (on/off). For the water temp, the sensor that Ffr puts in the kit to control the fan is a switch type, any chance you are using it instead of the sensor that came with the gauge?
Steve
I have the autometer gauges. I used the water temp sensor that came with the kit. As for the oil sensor, I used a standard motor ps60.
https://www.summitracing.com/parts/smp-ps60
JimLev
08-18-2019, 08:00 PM
Didn't your Autometer oil pressure gauge come with the correct sender?
FF33rod
08-18-2019, 11:45 PM
I have the autometer gauges. I used the water temp sensor that came with the kit. As for the oil sensor, I used a standard motor ps60.
https://www.summitracing.com/parts/smp-ps60
There's your problem. Use the water temp sensor that was in the same package with the gauge. Sounds like you're using the one that's intended to be used to turn on and off the fan - it acts like a switch, not what you want. Also, the oil pressure sensor that you picked up won't work (I did the same thing initially) - again, it's only a switch - Mustang's of that era did not have an oil gauge, they had an idiot light so all they needed was a oil pressure switch..... Locate the ones for the gauges and use those....
What sucks is I bought my kit used from a guy who had barely started it. I just assumed I had to buy different sensors. He had installed the one in the radiator already so I thought it was good to go. The one I bought for the oil gauge was for ford 302 so I thought that was good to go too. I'm an idiot! I just called autometer tech support to get me the correct sendors. They got it no problem.
* I still cant get the RPM's to register on the tach gauge. I'm sure that must be something stupid I did too! lol
It's the hyperspark ignition system so all the wiring runs through the efi. The manual for it says to use the tach output(dark brown wire) . As for the sensors could Teflon tape impede the ground signal. What about arp thread sealer? Maybe it loses ground that way...
When you say you're using the Hyperspark ignition system, what components are you referring to? Is it just the distributor, or complete CDI coil and control box as well? There are several permutations you could have, each will be wired differently.
Its the full system. I have the distributor, ignition coil and ignition box. All of it was plug and play. Only a couple wires go from the EFI back to the car.
The fuel pump, fan wire, switched ignition, tach output and negative/positive wires.
Its the full system. I have the distributor, ignition coil and ignition box. All of it was plug and play. Only a couple wires go from the EFI back to the car.
The fuel pump, fan wire, switched ignition, tach output and negative/positive wires.
Okay. Next, in the setup wizard, what did you select for RPM to Sniper/Ignition Type?
TxMike64
08-19-2019, 11:17 AM
It's the hyperspark ignition system so all the wiring runs through the efi. The manual for it says to use the tach output(dark brown wire) . As for the sensors could Teflon tape impede the ground signal. What about arp thread sealer? Maybe it loses ground that way...
I would caution against using teflon tape to seal threads on oil fittings. NPT has an inherent leak path through the thread root and minor diameters and needs to be "doped" to completely seal. In most cases teflon tape a a quick cheap easy seal. One risk with teflon tape is that the threads tend to cut the tape and those cut pieces can come loose inside the fluid path. This is exacerbated when too much tape is used, or if too much is placed too low on the taper of the thread. These loose pieces can flow into the oil passages and in some engines it doesn't take much to block a passage/galley: blocked oil galley = engine destruction. I don't know if I've ever heard of this actually happening, but the chance of it happening scares the hell out of me! A handful of mechanics and engine builders have all told me the same thing: use a liquid thread sealant, something like Loctite 592. Careful of using RTV on threads for the same reason as tape.
Just my .02
FF33rod
08-19-2019, 11:27 AM
What sucks is I bought my kit used from a guy who had barely started it. I just assumed I had to buy different sensors. He had installed the one in the radiator already so I thought it was good to go. The one I bought for the oil gauge was for ford 302 so I thought that was good to go too. I'm an idiot! I just called autometer tech support to get me the correct sendors. They got it no problem.
* I still cant get the RPM's to register on the tach gauge. I'm sure that must be something stupid I did too! lol
Idiot? Stupid? nope.... just learning. I did the same thing with the oil sensor a few months ago. The thing that pissed me off was that I went to the parts store to get an extension for the sensor that came with the gauges because it was too big to fit close to the block. The guy at the parts store talked me into the Ford part because it was a lot smaller. So he didn't even know that the Ford part was a switch and not appropriate for the gauge... We're all learning at one level or another... Good luck with the tach...
Okay. Next, in the setup wizard, what did you select for RPM to Sniper/Ignition Type?
Selected 800 rpm. When the car is running. it says 800ish rpm. So I know it's working right on the handheld.
FF33rod
08-19-2019, 07:53 PM
Caution, do not connect the tach directly to the coil when using CD boxes and such. The issue is those boxes can provide higher than 12V to the primary side of the coil to get higher voltage sparks to the plugs. The following is a warning from Autometer...
Warranty will be void if connected to
coil when using an aftermarket ignition
box such as, but not limited to products
from the following manufacturers: MSD,
Crane, Jacobs, Mallory, Holley, Etc.. Prior
to installation of your tachometer, check
with the ignition box manufacturer for
recommended tachometer signal location.
Selected 800 rpm. When the car is running. it says 800ish rpm. So I know it's working right on the handheld.
I'm referring to the setting for the ignition type in your handheld. There is a screen called "RPM to Sniper/Ignition Type". You should select HyperSpark. You are correct about using the tach wire from the EFI and as FF33rod said, don't connect your tach to a CDI coil. You now need to get the proper settings in the EFI computer.
https://thefactoryfiveforum.com/attachment.php?attachmentid=112623&d=1566269821
If you have that set correctly, I'm out of ideas.
I have used the hyperspark distributor as the setup feature. Can I use a test light to test the signal? seems light it would flicker from the pulses.
The Speedhut tach can accept several different tach signals, including an ECU signal after adding a provided resistor. I'm not sure how the Autometer tach works, but it may require a tach signal converter. You need to know what the Holley ECU signal is and what the gauge is expecting.
FF33rod
08-20-2019, 12:27 PM
Like Papa suggested, I was wondering if it required a resistor as well (commonly called a pull up resistor) but after searching through the Sniper manuals I can find no reference to that requirement so I somehow doubt it. I would have wired it exactly as you have Tony. I have exactly the same setup but unfortunately I haven't tried the tach yet and everything is apart at the moment so I can't run an experiment for you - in a couple of weeks I could.
As for attaching a 12V light - it needs to be one that runs on very little current - an LED, and of course you can't connect an LED directly across 12V, a resistor needs to be in series with it. Even so, you are not going to see "flicker" with 800 rpm or higher. You'd see flicker at 10-20 RPM or lower - LOL.
What you could try, no harm in doing it, is attach a 1000 ohm (1K ohm) resistor from the signal to 12V and see if the tach starts to work. This is the pullup resistor we are wondering about. I doubt it will but just to eliminate another possibility.
Steve
The Speedhut resistor that their instructions refer to is a 4.7-10K Ohm, 0.25watt minimum.
https://www.speedhut.com/instructions.i
I can't find any similar Autometer data.
JimLev
08-20-2019, 01:46 PM
On my Autometer tach I had to use a 10K pullup resistor.
This was an LS3 with the GM ECU, so it's apples to oranges.
I got the new autometer sensors installed. Oil pressure and water temp are registering correctly!
Also, probed the tach some more. Found a bad crimp. Tach works good now.
thanks EVERYBODY for your help! I'm onto the next stage....