Hi,
I am in the process of installing the Holley Sniper EFI system in my 87 Firebird 305 engine, which was carb.

I believe there are some on this site that have done this. My questions are: Will I loose speedometer?, I believe I will loose tach,

Is there any other losses that I should be aware of? How do I resolve these issues.

Thanks,

Louis

 

Is your speedometer cable drive ?
The tach can be hooked to the negative side of the ignition coil.

 

The tach is part of the engine harness, but connected to the coil, so you just need to retain that from the engine harness. I'd have to look in my factory manual, but the VSS comes from the trans and should either go directly to the dash, or a buffer box? That should be easy to retain also. You can also use the coil wire as the ignition source for the Holley harness, that is how I wired in my Holley EFI in my other vehicles.

I would start by reading the LS swap guide for the body side stuff, it will apply to any engine swap that isn't factory.

 

Hi Tuned,

The speedometer is not cable. My problem is where to find the tach wire.

Louis

 

Scooter, thanks. I have looked at the factory manual and other diagrams and cannot find the tach wire. Do you have any idea where it is?

Thanks,

Louis

 

The tach wires run through c100 it’s a white wire going to the coil. If you don’t have a cable drive Vss retain the wiring from the Vss to the Vss buffer. It’s all connected through the passengers side body pass through connector.

 

Hi Tuned, thanks for the info. much appreciated.

Louis

 

Tuned, when you say white wire going to the coil, I assume you mean the white wire marked with the red arrow in the attached photo.on the gray plug. The black connector with the white wire comes from the distributor.

The heavy red wire in the gray connector is the 12 volt I am using for the Sniper efi. Can you clear this up for me.

Thanks,

louis

 

Your correct on the white wire.

 

Great, one last question, I assume this wire will attach to the "tach" terminal of the HEI distributor that I am using. The install of the sniper has one wire already attached to the "tach" terminal, one yellow one labeled
"coil". Do I piggy back both wires?

And thanks for your help, really appreciate it.

Louis

 

Do you have a schematic showing the yellow wire or does it say coil negative?

 

You should really be referencing the instructions or the wire schematic from the Holley setup instead of asking us.

AGAIN reference what YOU GOT with your kit, but this shows page 6 that the yellow wire is for the tach input to the Holley system
https://documents.holley.com/199r11193.pdf

If this is what you actually have, then you could either use the coil negative for your tach, OR the brown wire from the Holley to drive your tach.

 

Scooter, thanks for your input. Instructions are sometimes not all that clear. Thats why its nice to ask people who have actually installed this system, Hence, I asked here.

Thanks,

Louis

 

I know this is a old thread . Just curious what distributor did you end up using ?

 

Hi, I ended up using a Summit HEI distributor with vacuum advance.I had initially hooded the vacuum to partial vacuum on the Sniper unit and was not happy with the timing. I ended up hooking the distributor vacuum to full vacuum and it works great.

Louis

 

Over all do you like the sniper, I’m debating on this system or just tbi. It’s for a old 76 Chevy truck.

 

Hi again, I am using this unit on my 87 firebird 305, formally carb engine. I changed intake manafold to accomatate the sniper.
All in all, I am very happy with the unit. I see more power, a little better gas mileage and fast starts. You can just install it with the recommended settings and forget about it or if you are inclined, go crazy with tunning via laptop.

Louis

 

Thanks for the feedback, I can’t leave well enough alone. I would tinker with it lol.

 

Yeah, you can really get into it. Great product. If you are really interested, I would like to direct you to this man, Chris Meyer, he is a licensed Holley dealer. He is the best to deal with.

http://www.EFISystemPro.Com

 

Thank you very much

 

Let me know if you need any help. Its a fun project.
Louis