Holley Sniper EFI install

Sniper was installed during the rebuild.   I am in the dark about the installation details.   During the couple months I drove for a "shake down", either my driving skills are extremely poor or the initial setup needs some trwicking.   the car is  currenly back in shop to correct a few other problems and improving drivablity is one of the items.

the big drivablity is touchy throttle response from a stop, while feathering the clutch pulling away.  (over reving)

so when I get car back and take over maintaining, I have feeling I'll be asking a lot of questions.

I do know, the temperture sensor is the snipers in the front of the block.   Very nice having an accurate coolant temp on the display.   My dash guage sensor was installed in the water pump inlet (displays about 20F lower)

Hi jfb05177,

Great to meet you and hear your experiences. :-)

also thx on the info of the temp sensor.

when will you get your back in your garage again, you think?

I’ll update on my progress on the install very soon, still waiting some spare parts and also still creating the “master plan” for the install in my head.

I hope we’ll hear from several more. :-)

Cheers

chris

I hope you are installing the Holley Sniper2, and not the original one.  The original one had a lot of issues, even admitted by Holley engineers.  Sniper2 works magic.  I just had mine installed and finished.  It has been great thus far, and hasn't even been tuned yet.  Goes in on Monday for that.

I had the same throttle issue instantly.  Garret, the metal fabricator guru I have referred to a lot in past posts, welded an extension to the throttle arm and it fixed the issue instantly.  Now car revs up smoothly.  Prior to the fix, it was difficult not to start accelerating fast.  Basically I couldn't drive slow in a parking lot.  It just jerked forward and sped up.  Couldn't ease the throttle; now I can.

Any and every question you would have can be answered by my mechanic, Scott, who did the installation.  He has done several of these installations and pretty much did it with his eyes closed.  PM me and I will give you his contact number.

Also, I bought a tachometer adapter from Jon Haas at Pantera Electronics, which you will need to get your original mechanical tach to work with the Holley Sniper.

Fuzz

Hi Fuzz,

Thanks alot for your message, really appreciate your help and willingness to help, I'll for sure take oppertunity of that, when possible. :-)

It's the pre-2 version of the Holley Sniper. I bought it just a few months short of 2 years ago, and at that time I wasn't aware the was or would come a version 2. I didn't get around to install it before now. But now I see no other option than to go with the one I got, the version 2 is expensive like the 1 version also was, so can't afford just to buy the new one and throw the "old" one un-used away.

So'll have to cross my fingers and hope it will work okey for me. I hope the best. :-)

Cheers

Bryske

the sniper stealth will accept a standard air filter.

Bryske,

Have you tried calling Holley to see if it's possible to exchange or update your Sniper to Sniper 2 spec.? The main difference between the two is the throttle body. They do have an upgrade kit available (Part # 550-511-3AX - $1,099) but since your throttle body has never been used, they might do better. It's worth a telephone call.

@davidnunn, yeah, I think if I lived in USA, that could have been worth a try. Unfortunately I live in Europe (Denmark), so even if Holley is helpful, I would be looking at a very expensive exchange. You know, shipping back and forth and even worse, let's assume I got it at half price, eg 500-600$, the taxes and customers into Denmark are extreme, it would be multiples with x1,4. And I think the shipping costs would easily be 150$ at least. So though I would love to get the Snipper v2, I think it's going to be impossible. Unless you believe they would do the swap for eg 100-200§, but personally doubt that.

Hi Everyone,

I'm late to the party, but also in the middle of installing a Holley Sniper Stealth EFI system.  I bought it almost 2 years ago, but life has gotten in the way of installing it (death in the family, the birth of 2 grandchildren, the marriage of my youngest daughter, and the move of my son from Dunedin, FL to Enumclaw, WA).  In any case, I'm working on it now.  I've heard how great the Sniper2 is, but I don't see that the "stealth" model has a version 2.  Does anyone know?  I'll call Holley tomorrow morning to find out, and see if they'll exchange my new in the box Sniper Stealth for the new version 2, if it exists in the Stealth model.

I'm installing the stealth version because I want to use the stock air cleaner, which doesn't fit on the standard Sniper throttle body.  I also purchased the entire Holley ecosystem so all the connections should be plug and play. Following is what I purchased:

• Holley Hyperspark CDI box
• Holley Hyperspark coil
• Holley Dual Dual Sync Distributor
  • I originally purchased the Hyperspark Distributor, but the damn thing was 4" taller than both the stock distributor and my Mallory Unilite distributor, so it would never fit under the engine screen.
  • The dual sync distributor is low profile, but it's for a 351W, so I changed out the distributor gear for a Cleveland gear compatible with my roller cam.
• 3/8" copper-nickel tubing to fab new fuel lines.
• Walbro #GSL392 external fuel pump, mounted to frame rail under the gas tank.
• Bosch #17025 O2 sensor
• Wix #33033 pre-filter

• Wix #33482 post-filter

Now on to my questions...

1. The Sniper Stealth requires an external fuel regulator with bypass for the return line.  I was thinking of mounting it high on the firewall adjacent to the gas tank as there's plenty of room there.  If you installed the Stealth version, where did you mount the external regulator? 
2. What wire in the stock harness did you use for your 'switched 12v' source?
3. Did you run a dedicated wire all the way to the front trunk to connect directly to the battery as the instructions insist, or merely connected to the BATT terminal side of the starter solenoid where the heavy gauge cable comes directly from the battery?

Thanks for any info and pics, and/or additional part numbers for various fuel fittings, etc. that I will need.

@garth66 posted:

Now on to my questions...

1. The Sniper Stealth requires an external fuel regulator with bypass for the return line.  I was thinking of mounting it high on the firewall adjacent to the gas tank as there's plenty of room there.  If you installed the Stealth version, where did you mount the external regulator?
2. What wire in the stock harness did you use for your 'switched 12v' source?
3. Did you run a dedicated wire all the way to the front trunk to connect directly to the battery as the instructions insist, or merely connected to the BATT terminal side of the starter solenoid where the heavy gauge cable comes directly from the battery?

Thanks for any info and pics, and/or additional part numbers for various fuel fittings, etc. that I will need.

I have Terminator X for my TWM 8 stack EFI and can answer number 2 and 3.

2.  It is just the the switched 12v wire coming from the ignition switch.  Terminator X is not pulling a bunch of amps from this wire.  It just lets it know the key is in the run position.

3. No need to run a wire to the battery, just use the BATT side of the starter solenoid.

I have tested everything you see below and get spark from the coil when I spin the Dual Sync distributor manually.

Another question on the sniper install. I find that my throttle cable extends about 5/8” past the pin it connects to on the linkage for the sniper.  Did anyone else run into this?  Thinking I may need to fab a throttle lever extension bracket to extend the mount point rearward. Or possibly fab a new bracket to relocate the stock throttle cable forward 5/8”.

Just curious what others have done…

Hey Garth -

Any chance to take up some of the length at the pedal end of the cable?

Do you have an adjuster up front?

Rocky

i believe everything came with the kit, but it’s also possible someone made the throttle bracket, i can’t remember

You still have threads left to shorten the cable seems like…. You have the same threaded connection on the gas pedal as well…

@LeMans850i posted:

You still have threads left to shorten the cable seems like…. You have the same threaded connection on the gas pedal as well…

Brilliant!  I didn't even see that!  I guess climbing in and out of the engine compartment for hours on a 95-degree day dulled my senses.

Thanks!

  @garth66 Well, you need a mental boost:

… did it help?? 👍

@LeMans850i posted:

  @garth66 Well, you need a mental boost:

… did it help?? 👍

Just saw the suggestion, so I'll check it tonight.

Check at the accelerator pedal as well.  It’s the same ferrule and threaded fixture rod.

Rocky

Just wanted to add my 2 cents here.  When I had my Sniper 2 installed, the throttle bracket was not moving all the way back, and thus I was not getting full throttle.  I don't recall exactly what it was hitting, but it was hitting something and the lever arm had to be extended.  I had a metal shop do that for me.  But when I took it to be dyno tuned, the guys at Race Krafters (Lancaster, PA...GREAT guys by the way) saw fuel was at 60% max delivery and hp was no where near what they thought it should be.  HP was coming in at around 290 (if memory serves me correctly), which they felt was way low for my engine.  Anyway, they took off the throttle arm, cut off the pin and moved it to the top of the lever arm, and adjusted the cable, resulting in 100% fuel delivery (according to their very impressive diagnostic machines).  After roughly 14 dyno pulls and full engine and Sniper 2 tuning, engine was producing 386 hp , with 405 ft-lbs of torque.  These numbers where at the wheel, so probably 445-465 hp at the engine. It is imperative to get that throttle body perfect or you are leaving a lot on the table.  Based on my own experience, I would say eyeballing the throttle body movement after the Sniper installation is not enough and it really needs to be tested and tuned on a dyno with folks who are experienced.  In my case, Race Krafters were/are Holley Sniper EFI dealers and installers.  I had called Holley and they looked up their dealer/installer networks and referred me to them.  I think no matter where you live, they will be able to guide you to someone who can install, test, and dyno tune the system for you.  GOOD LUCK!

@Fuzz posted:

I don't recall exactly what it was hitting, but it was hitting something and the lever arm had to be extended.  I had a metal shop do that for me.  But when I took it to be dyno tuned, the guys at Race Krafters, they took off the throttle arm, cut off the pin and moved it to the top of the lever arm, and adjusted the cable, resulting in 100% fuel delivery.

Would you post a pic of your throttle arm on the Sniper where the throttle cable attaches.  I would love to see what Race Krafters did.  Thanks!

Here you go

Just asking stupid me… There is no secondary return spring installed?

@LeMans850i posted:

Just asking stupid me… There is no secondary return spring installed?

For mine I have dual return springs, but not installed until I get the throttle cable attached.

This photo is from May when I had it dyno tuned. That is the same day the guys at Race Krafters made the required modification on the throttle arm. I don’t remember if I took the photo after everything was put on or it may be possible it has a return spring and I took the photo before it was put on. I have to get in there and look and then report back to you.

Fuzz

@LeMans850i posted:

… There is no secondary return spring installed?

there are torsional (mouse trap) springs on both primary and secondary plates.

the shop did NOT install a throttle return on mine at all. 

I have a problem with idle being erratic.   I just noticed the secondary is sticking!!!!   there is a youtube showing the recentering the secondary plates (by loosing screws to shaft and retighting).    I don't want to go that far (yet) and plans today is to add an extension spring to the secondary, maybe another to cable.

@jfb05177 posted:

there are torsional (mouse trap) springs on both primary and secondary plates.

the shop did NOT install a throttle return on mine at all.

I have a problem with idle being erratic.   I just noticed the secondary is sticking!!!!   there is a youtube showing the recentering the secondary plates (by loosing screws to shaft and retighting).    I don't want to go that far (yet) and plans today is to add an extension spring to the secondary, maybe another to cable.

I would send the unit to a dealer and let them take care of the issue….

I’m Having issues with the sniper, it’s always backfired under sudden acceleration, i recently took it on the freeway and got the car up there in speed, it almost sounded like the valves were floating but it was certainly backfire, after that the car backfires through the car on any acceleration.

i just ordered a new O2 sensor that gets here today, verified and added/improved grounds.

checked compression in all cylinders.

i had the car tuned by a knowledgeable guy but not on a dyno. he thinks it’s a valve guide/spring issue because one cylinder was 5-10% higher than the other (also had a wet plug)

well known great engine builder said he only used top quality everything and believes it’s a tuning issue.

any thoughts or insights

@Bell3156 posted:

I’m Having issues with the sniper, i...

i am having similar symptoms.  (plus others)

I changed target A/F from 14.0 to 14.5.   I "think" that made improvement.  but I ease into throttle now.   I think it goes very lean with initial throttle increase.  the manual does not recomend changes to "accel pump" setting

I've notice that after change, the "improvements" occured after the next crank.  so hoping it "learns" that very little throttle opening needs extra fuel

I changed air filter because the INSIDE was black

Dan,

Before you do anything else, I'd have a look at what is causing your wet cylinder. I had a similar problem and it turned out, the rings in one cylinder had not seated properly. Ugh. The solution involved new rings and honing the cylinder. I hope that is not your problem!

It's doubtful your O2 sensor is bad although oil from the wet cylinder may be fouling the O2 sensor. When you remove it, you'll know.

Good luck!

Details- the o2 sensor(s) go in the side or top of the collector anywhere between the last pipe branch and the long extension to the muffler. Do NOT put it in the bottom of the exhaust because depending on the climate where you live, upon starting, momentary condensation in the engine runs like a river on the bottom of the pipes and water is a sensor killer. Its kind of a tricky weld job to add the screw-in boss(es) while the headers are in the car. Use anti-sieze on o2 sensor threads.

Any electric fuel pump that's the same OD as a stock Ford electric pump will fit inside the stock tank (either early or late) thru the fuel sensor hole on the top. There are two identical looking fuel pumps- one for TBI-injection (14 psi) while the other is for multi-point EFI (50 psi). Dunno which Holley specifies. You'll need to add a sealed power wire thru the stock fuel sensor top to power any in-tank pump.

Mounted inside the tank like millions of other Fords since the late '80s, fuel pumps run much quieter and cooler. There's an illustrated POCA Newsletter article from about 15 yrs ago on this. I use mine as a carb primer or emergency pump backup.