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Holley Sniper first time bad results.

I have not done an oil pressure on any I've installed. Not sure it supports that. I'd have to look into it further. I know the supplemental harness can do fans and other things Just not sure it can read a oil pressure sensor.
Here is an entire topic related to reading a oil pressure sender. It looks like its not possible unless you use a Holley Digital dash.
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I know if you have Dakota Digital Gauges like me you can use a EFi ICM from DDG and it will share a few things but like you not for sure on oil. I just used ordered one to clean up some wiring and use less sensors on my water pump.
 
69 GTX 440. Interesting thinking of installing the sniper also. Any suggestions.??
Unless you know he to tune the sniper and know the thing inside out don’t do it stick with the carb. I have one on my 69 GTX 440 and it will not run with a damn very rich no matter how I set the AFR. I believe my fuel map is screwed up, and it is hard to find someone that knows how to adjust the fuel map.
 
Unless you know he to tune the sniper and know the thing inside out don’t do it stick with the carb. I have one on my 69 GTX 440 and it will not run with a damn very rich no matter how I set the AFR. I believe my fuel map is screwed up, and it is hard to find someone that knows how to adjust the fuel map.
I can help.
 
Unless you know he to tune the sniper and know the thing inside out don’t do it stick with the carb. I have one on my 69 GTX 440 and it will not run with a damn very rich no matter how I set the AFR. I believe my fuel map is screwed up, and it is hard to find someone that knows how to adjust the fuel map.
 
My friends 70 GTX which lost that cam and I swapped engines has an issue of the Sniper screen turning red with "no data" on every part of the dashboard. When it does this it just dumps fuel like the injectors are wide open. It was so bad that it overfilled the oil pan with gas. even Hydro locked the engine.

I drained the oil pan, changed the oil and pulled some plugs turned it over. So upon googling I found a video on Youtube that describes this very well. Apparently I'm sending back a Sniper unit, something is wrong internally or a bad board.

Now here is where I get to thinking. When he lost that cam he said it backfired and popped and then shut down. I am wondering if the Sniper/Fuel dump thinned the oil and caused it to wipe the cam? I assume fuel in an oil pan would evaporate over time and maybe the oil would smell a little gassy. Anyhow below is a video that explains this perfectly.


I have installed both Holley and Fitech systems and used HP programmer to do swaps. From your description kind of hard to give you a cause. But The injectors are controlled by drivers basically a transistor. If the driver gets a big load on it, it will shut down. Causing a problem like you describe. First thing I would check is the fuel pressure, the more fuel pressure the more amperage it takes lift the pintle in the injector, too much fuel pressure can overload a driver. The other thing is the main power and ground has to hook directly to the battery, if it does not all kinds of interference will mess with the computer. The only thing I do not like about the holley systems is the fact they do not set failure codes like a OEM system. FiTech systems do set codes and at least for me are a little easier to figure out.
 
OP, if you flashed the software and the system started operating correctly, I'll share a bit of knowledge with you. If a holley equipped vehicle has the battery connected and the battery goes dead, even drops below 9 V while cranking, it can corrupt the firmware, requiring a reflash of the firmware. This isn't the same as disconnecting the battery, it's a slow drain of it. I've seen fuel injectors go wide open, ignition timing be so retarded it makes headers glow at idle, etc. Is it optimum, no, does the unit work great, yes. It's a pita, but the system is pretty solid other than that. I was made aware of this by one of the Holley engineers and there's some threads on their forum about it.
 
Sounds like the holley system needs a small "trailer brake emergency" style battery hooked up to it as a "buffer" system. With the correct install it will charge off the alternator but won't drain off the main battery when cranking so the ECU always sees 12V+.
 
Sounds like the holley system needs a small "trailer brake emergency" style battery hooked up to it as a "buffer" system. With the correct install it will charge off the alternator but won't drain off the main battery when cranking so the ECU always sees 12V+.
That's a fuckin incredible idea. I just disconnect the battery or keep a tender on my holley cars. Had a guy put a cheap charger on his and it corrupted the software, it was a headscratcher. I reflashed his software and disconnected the battery and hooked up his battery charger and no more issues. Electronics can really defy logic sometimes.
 
Just any idea, I have no idea what the current draw is on one of these. Battery cranks and voltage drops, but if the ECU only is running off the small battery, that is diode protected from any main battery draw, then the ECU will always see 12.6 or better.
 
Just any idea, I have no idea what the current draw is on one of these. Battery cranks and voltage drops, but if the ECU only is running off the small battery, that is diode protected from any main battery draw, then the ECU will always see 12.6 or better.
It is essentially how a Stop Start mopar is done, one small battery to operate the pcm and various amenities and the large battery is strictly starter. Once engine is running, the batteries share charging from the alternator.

I wish I was closer to you, I'd like to see a diagram or explore this more. I like out of the box thinking and this is an excellent one. Thanks!
 
Sounds like the holley system needs a small "trailer brake emergency" style battery hooked up to it as a "buffer" system.
That's my plan. Might put the main battery in the trunk and the "EFI battery" in the usual place.
 
I tried the FiTech 600CFM system, and it did not work with my '69 Charger big-block 440 with headers... just too much heat in engine compartment for the built-in throttle body ECU to function correctly. It worked great with a cool engine, but suffered random results when engine got up to temp. no matter what I tried... just too hot ! I gave up on it and went with an Edelbrock 1411 carb. last year. Still fine tuning it, but at least it doesn't stop cold in the middle of driving because fuel pump shut off, or ECU reset, etc. like with FiTech... it was beyond frustrating ! Perhaps a small block or rat rod car with alot of airflow is the ticket to success... ( at least for me )
 
I tried the FiTech 600CFM system, and it did not work with my '69 Charger big-block 440 with headers... just too much heat in engine compartment for the built-in throttle body ECU to function correctly. It worked great with a cool engine, but suffered random results when engine got up to temp. no matter what I tried... just too hot ! I gave up on it and went with an Edelbrock 1411 carb. last year. Still fine tuning it, but at least it doesn't stop cold in the middle of driving because fuel pump shut off, or ECU reset, etc. like with FiTech... it was beyond frustrating ! Perhaps a small block or rat rod car with alot of airflow is the ticket to success... ( at least for me )
I've never experienced that on a sniper. That is unfortunate for you and understandably frustrating.
 
I never have bad results with Holley Sniper systems.
Because I use a good, reliable carb [ Carter AFB/AVS/TQ or Edel ], which run for 000s of miles trouble free.
 
I never have bad results with Holley Sniper systems.
Because I use a good, reliable carb [ Carter AFB/AVS/TQ or Edel ], which run for 000s of miles trouble free.
As do my Holley carbs. :poke:
 
Holy **** just finished most of my wiring for my X-Flo. What a major PITA! Especially trying to hide everything and make stuff look neat. Felt like I had to rewire the complete engine bay especially tying everything in with my electric fans and vintage air. Still like a few more things like hooking the ignition box up inside the car, fuel tank, wires and filter.
 
Here’s mine, I’m working on fabricating the 3/8” stainless hard lines still.

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