Sniper - No Data Issue - Need Help

[Jrhamilton-68GTO]

Hi, JR Hamilton. I have a '68 GTO, Pontiac 461 Stroker engine that was recently build and dynoed by Kauffman Racing. The engine ran with the HyperSpark and 550-510 Sniper on the dyno, and ran great from the builder.

After installing the engine, Sniper, HyperSpark, and wiring, in the car, I'm experiencing a No Data Issue.

The engine will startup and run great for 5-10 seconds, then a "No Data!" will flash on the Closed Loop & Learn Status screen, and the car will start to cut out. The engine will back fire, cough up fuel through the throttle body, flash "No Data!" on the handheld, and will eventually die.

The timing and fuel pressure is spot on while running. I've attached a datalog file for reference. Any help on where to start is appreciated. Thank you for your help!

[GPatrick]

If you open the datalog, you'll see that there are negative time values. This is an indication of a Sniper ECU reset due to EMI/RFI. This is often related to wiring of the installation in the car. Since the engine ran on the dyno we know the that the ECU is capable of running properly.

Examine all of your wiring and pay attention to the position of Sniper wiring and any ignition wiring. Where do you have your Sniper pink wire attached? Are the main power & ground wires both run directly to the battery? If you can, take a picture of the engine around the distributor so we can see the wiring, the position of the coil, and the spark box. Was the distributor removed when you installed it in the car?

Do some searches on EMI/RFI on this site to see some of the solutions.

If you ran the engine with the air cleaner installed, see if it runs any differently with the air cleaner removed.

The battery signal on datalogs comes from the pink Sniper trigger wire. The battery voltage reading is very noisy and in the lower 13 volt range in the datalog. Alternator noise has been known to cause EMI/RFI conditions and cause resets. To test, remove the alternator belt and see if the engine runs better. Any alternator wiring that is near the Sniper should be moved. The TPS wiring on the front passenger side is susceptible to noise. Was the engine run with the alternator on the dyno? Are you running the original OE style alternator? More modern alternators are designed to run with minimal noise and they produce strong voltage at idle speeds. Some one wire aftermarket alternators produce a lot of amps, but they're sometimes not EFI friendly.

[Danny Cabral]

https://forums.holley.com/showthread...790#post104790 (Holley Sniper EFI Alternator Information For EFI Applications)
https://forums.holley.com/showthread...-Installations (Holley Sniper EFI RFI/EMI Issues)

[Jrhamilton-68GTO]

Patrick/Danny. Thank you for the information. I think I had issues with the HyperSpark distributor wires (green/purple/pink coming in close contact with the spark plug wires, along with the Sniper ECU wires close to the ignition wires. I drilled a new hole in the firewall and placed them well out of the way of the spark plug wires.

I have a serpentine belt system with a new March alternator. I took off the belt, which did not make a difference with the alternator, and kept having no signal interference. I rewired everything including my 12V switched ignition and placed it on a 12V switched relay. In the end, I wasn’t aware of how sensitive the Sniper wires are to EMI/RFI with being in contact with other wires. I think I should be in good shape! Thanks again for your information.

[WyattM21]

I'm experiencing this same issue on a Sniper 550-519 with HyperSpark. I've installed it myself and it has been running well for about two years now. Long story short, the engine ran great last night, but this morning when I put the key in the ignition, the 3.5" handheld came up all red, and "No Data" for all the sensors. The fuel pump also did not kick on. Usually you can still hear the injectors try to fire with a bad ,but they failed to prime as well. I have verified power and ground to the Sniper throttle body, the distributor, and the HyperSpark box. I'm assuming it might need to be sent to Holley for inspection of the ECU. Any thoughts before I make the call tomorrow?

[a b c]

Reload the GCF or a different GCF, and test it.

[GPatrick]

Did you measure voltage at the fuse on the large red wire? If not, how did you configure voltage?

[WyattM21]

I tried connecting the laptop to see if I could change the tune, but with the key turned on the laptop isn’t able to connect. I did try pulling the SD card and loading in a new GCF into there with no success. The picture I added is all I'm getting.

I’ve checked my main fuse voltage which is good. I’ve also checked the switched voltage that all seemed good as well.

[a b c]

Looks like a call to Holley is in order. Make sure you don't have any furry friends chewing on your wires.

[gmc2313]

My system did the same thing. Cruising at 30 MPH and it just shutoff and the handheld looked just the one above all read no data. I jumped out and opened the hood and heard what sounded like water running, but it was the fuel pump filling my engine with gas even though the key was off. Needless to say that sucked. I think something is wrong with ECU. I'm running Sniper 550-511 with HyperSpark distributor, Sniper ignition coil and box in 1975 K10 with stock 350 SBC.

[gmc2313]

Called Holley and they said it may be the unit, but would take 8-12 weeks before they could look at it. Very disappointing.