scottjamison

Does the EFI retain the settings when you unhook the power?

zwede

Yes, all settings are retained. I've had the battery disconnected for a couple weeks and it didn't lose anything.

scottjamison

I was just checking out my new parts, starting to form a plan for installing everything and something dawned on me.
Currently my PCV valve line goes to the inlet on the base of the Carb. The Sniper doesn't have that vacuum fitting.
What do you guys do with your PCV valve? I could take it into the air cleaner or directly into the intake manifold. Or just run it without vacuum on the PCV valve.

Thoughts?
I will say I am happy to see that I have enough Earl's fittings left over from buying wrong sizes in the past that I don't need any new ones! Yes!

zwede

The Sniper has a 3/8" vacuum port you can use for PCV. That leaves the brake booster and headlights which I hooked to two manifold ports.

I would not recommend skipping the PCV as it's beneficial to the engine (removes condensation from the crankcase).

carriljc

You can get that housing for 8-12 bucks at autozone:
(I removed the picture/link because I do not know what is considered ok )




*

Stingre'

I did the same setup as most, 3/8 and 5/16 existing supply/return. Mine went flawlessly, I was seriously amazed the first time it fired, I barely cranked the ignition and BAAAM !
I was going to go LS fuel filter where the return line goes back the the inlet of the filter but after reading here that the 5/16 return line worked fine I went that direction. I still have the fuel filter and all the connections it interested...

BlackC3vette

edusmc1

scottjamison

Fantastic. I am doing mine starting TODAY!
Twin brother is in town for a two man effort this weekend. Tank, ignition, and throttle body.

gjjcvette

Wow! That's great gas mileage. How much do you get when just driving around town? Also, which EFI system would you recommend nowadays? I'm on te fence between the Atomic MSD and the Sniper...

Jd21476

How do you connect the tach wire if your tach is a tach drive distributor?

Rescue Rogers

The MSD would have the controller for it and it has a separate wire for that. The atomic probably would as well. And if its for the sniper depending on the wring harness it is mixed into the harness already. But you dont need to use the ignition control for the EFI and Sniper suggests you dont until it has some significant learning already stored

Jd21476

I do have an MSD distributor and box so could I just wire it in to that?

Rescue Rogers

the directions will tell you if you need it and where to hook it up. Are you trying to use the sniper to control your timing?

ctmccloskey

I see that you are using an external pump for your Sniper on your installation. I have a Holley "Stealth" Sniper which requires no return line and more accurately fits and looks like a standard Holley Carburetor. When I bought my system I had budgeted ($2500) including a new EFI fuel tank but when I placed the order the salesman asked what condition my fuel tank was in and then suggested the Holley OEM Fuel Tank Module. The OEM Fuel Tank Module is a New sending unit plate that has an Internal Walbro 255 Liter per hour Fuel Pump and an Internal pre-set 58 psi Fuel Pressure Regulator and a brand new sending unit. I pulled the Bottom plate off the tank and had my new EFI Fuel system installed in less than 1/2 hour. With the Fuel pump inside the fuel tank there is virtually no noise and the pressure regulator inside means 1 fuel line going to the Stealth Sniper. I was able to get everything including the Stealth Sniper and tank Module for ~$1700 and the system works great. The Fuel Tank Module even comes with a piece of the new Holley Hydra-Mat as part of the system. The Hydra Mat alone is worth $187 so getting one as "part" of the Sub $400 kit was great. Check out the Hydra-Mat and you will be amazed at How it works, It will pull gas into your system even when partially exposed to air.

I was most concerned about having problems during and after installation so I searched High and low before settling on buying the Holley Stealth Sniper from EFIsystempro.com. They had my system to me in 2 days and they give you two YEARS of incredible support from a Holley Tier 3 Trained Technician on their Staff. The Tech called me before the parts arrived and introduced himself and gave me his personal contact info so I could reach him anytime I was having problems, IF I had any problems. The advice he gave me was to set up the fueling part of the system and get it working before attempting the ignition controlling part of the system. This was good advice and I followed it. The Holley Sniper and Stealth Sniper are great systems and the quality of the parts is awesome. My system primes the pump like most modern EFI cars do when the key is first turned and then the pump runs very quietly after startup. The installation was much easier than I thought it would be but with awesome help I was not intimidated by the equipment.

I have a MSD Billet Distributor with the mechanical tachometer drive built in as I have a 1968 C3 with the mechanical tach. I have been able to lock out the centrifugal advance and removed the vacuum advance allowing my MSD to work with the Holley Software to control the timing for my Corvette. EFIsystempro will sell you a new Holley Distributor if you want to use one but the help I have received has been incredible. My system operates using the MSD 6AL box and even pulls the timing to allow my high compression engine to start without the drag of the full timing while cranking. The Holley Stealth Sniper like the Sniper can run Nitrous either wet or dry and it is very easy to do. I have a Water/methanol Injection system due to my compression and it is now running using the Holley EFI Software. The system was designed and built with us in mind, it does most of the learning on it's own unless you want to do it on a PC using the free software. Take a look at their software some time and you will be impressed, Holley really did a great job with its development as it has so many different ways of adjusting or modifying the software to make your engine run better. I have made back-ups of the data from the memory card but didn't need it as the car had no problems sitting all winter with the battery removed.

I have been very happy with my installation but even happier with the company I bought my system from. EFIsystempro has been there every step of the way! The support I have received has kept me from the waiting times at Holley's phone line or website for tech support. Questions are answered very quickly and I sometimes feel like I am their only customer they way I have been treated. I love the service I have received when I needed it.

There has been some newer stuff that has come out since I bought my system, a knock sensor is now able to be used on the newer Terminator EFI system by Holley as well as multiple programmable inputs that the Snipers do not have. If I had to do it over I would have bought the Stealth Terminator just to have the knock control feature with my 12.25-1 Compression ratio. The OEM Fuel Tank modules are available with a 355 liter per hour pump as well which would help those of us making 600 HP or over. Never the less my Stealth Sniper Looks just like a Holley Carburetor and fits under the Factory L88 Hood and intake parts I have on my engine. The Stealth Sniper only needs one line for fuel and that is a big plus as I didn't want to have to run gas back to my tank even though it has a return line built on to it.

Even if you did buy your Holley EFI system from another company the website for EFIsystempro has a lot of really good information on it. They will even help you pick out the best system for your applications. I have never received service like I get from EFIsystempro. They ended up helping me save several hundreds of dollars over what I had budgeted for my conversion. This and their after the sale service makes the the VERY BEST place to buy a Holley EFI System. Many people have looked at my Corvette and they can't tell it is running a EFI system unless I have my Fuel Pressure gauge on the system at the time. I considered the Edelbrock Pro Flow system but it is not in the same class as the Sniper or Stealth Sniper is. The newer Terminator systems can use a multi-port system with individual injectors or a throttle body with 4 injectors like mine has. I have 4-100 Lb injectors in my 427 and it runs great. I am still using a Edelbrock RPM Air Gap Dual Plane intake manifold and there is no squeal or anything unusual with this manifold.

And lastly, NO, I do not work for EFIsystempro. I am just a very happy satisfied customer of theirs and strongly recommend them to anyone interested in a great Price and the very Best in after the sale service. Check them out and I think you will understand why I am a believer in both EFIsystempro and Holley as they have made a great product with the very best service after you received it. The only part I needed to make my system "perfect" was the Progressive Throttle linkage which opens the four barrels like the Double Pumper does. I can't say enough for the ease of getting and the Quality of the support I get from EFIsystempro.com. I am and will be a customer of theirs forever!

Best Regards,
Chris

iokepakai

Since you have the tank pulled ,better to install the Holley retrofit intank pump.I had nothing but issues until I went this route ..Fuel pump will last longer no noisy pump and no need for a return line.The Hydramat pickup ensures no fuel starvation problems with low fuel levels...Good going with the install!

Boreas-Rex

When you installed your Sniper system, you did some drilling to install the fuel pump. You likely also ran some soft lines. If you made your own fuel log there was likely cutting involved. I am speaking from experience. Did a beautiful, nice clean install, custom lines from end to end. Got everything fit up perfectly. I’m my excitement to get her fired up, I neglected to blow out all the fuel lines. So all that debris, wound up in the injectors. So everything looked great to the regulator. I’m
fairly certain this is what you are experiencing. If by chance it is not, ensure your vent is higher than your fuel tank.

C6-CYa

FYI, you are responding to a four year old post from a member who hasn't been on the forum in six months, and stated he fixed his problem...