Holley 137K subscribers Subscribe 911K views 13 years ago Carburetor Installation & Tuning Segments Learn More: https://www. No timing control, no (spark based) Rev Limiter. If it works, the ECU will cut spark at or near 1500 RPM, then you can let us know for certain if it works or not. Sniper EFI Installation Tips from Holleys Tom Kise>Top 10 Sniper EFI Installation Tips from Holleys Tom Kise. When using a Holley dual sync distributor to utilize timing control capabilities does it plug and play with the Sniper EFI? Almost, You will also need the PART# 558-493 adapter that will allow it to plug into the ignition connector on the Sniper harness. You also have 2 vacuum port holes at the back of the intake. Reconnect the appropriate vacuum hoses to the Sniper EFI throttle body. com or do what I did, and go to http://www. Just like a carburetor, the throttle body is fitted with multiple vacuum ports: One large 3/8-inch port for power brakes, a small 3/16-inch . Holley Carb: Ported vs Manifold Vacuum Advance. com/i/Edelbrock/350/7501/10002/-1 ) and the picture they had there shows the port that I referred to on the back runner of the intake. When using a Holley dual sync distributor to utilize timing control capabilities does it plug and play with the Sniper EFI? Almost, You will also need the PART# 558-493 adapter that will allow it to plug into the ignition connector on the Sniper harness. Please read all the WARNINGS and NOTES, as they contain valuable information that can save you time and money. Reconnect the appropriate vacuum hoses to the Sniper EFI throttle body. Its part#1044 and you can purchase it directly from their website www. XFlow does not have a ported vacuum port that would typically be used with a vacuum advance distributor. It is situated in the central highlands, 1,500 feet (460 metres) above sea level and 70 miles (110 km). Holley>COMPETITION CARBURETORS MODEL 4150 HP SERIES. If youre not using power brakes (or if you have the booster plumbed to the intake manifold), use that one for your PCV hookup. Holley offers a variety of fuel pumps, hoses and accessories to complete your installation. I’m trying to make sure the larger threaded port in the front of the Sniper 1250 baseplate (4150, not the Stealth model) is just a plain old manifold vacuum source. Be sure to plug any vacuum sources not used on both the Sniper EFI Throttle Body and on the Engine. Not the 1/16” port which is used when running a draw through application, the larger port to the driver’s side. The Sniper line of products are built to take your project to a new level of performance at a great price! Sniper plumbing is high-performance equipment with hand-polished aluminum fittings and high-strength hoses. Ill use the manifold 3/8 for brake booster, the manifold 3/16 for ignition advance and leave the 3/16 ported capped. Holley Sniper EFI install. Some of the Holley 4150 carburetors, and just about all of the Holley 4500 (Dominator) carbs do not come equipped with the typical pressed-in vacuum port for hooking a PCV valve hose to, as some Holley and other brands of carbs do. Use one for your power booster and use the other for a multiple vacuum port. Specs- 350 engine, Edelbrock Performer EPS manifold, Holley 4160, TH350 trans (rebuilt w/shift kit), 3. Question: There is a threaded plug on the front of the throttle body. Can I just cap off the Sniper vacuum port and leave in the manifold? Last edited by ngstahl; 05-09-2020, 08:49 AM. 2 block, forged steel crankshaft & H-beam rods, forged pistons, Trick Flow Twisted Wedge 11R 205 CNC Comp Ported heads, 12:1 compression ratio, 232°-244° duration/. I have the Holley HyperSpark system, so theres no vacuum advance on that I don’t think. Connect the PVC to the 3/8 nipple on the front of the EFI thats designated manifold vacuum/brake. Where to Hook Up Vacuum Lines On A Holley Carburetor Holley 137K subscribers Subscribe 911K views 13 years ago Carburetor Installation & Tuning Segments Learn More:. The only issue that I have with this unit is the loud suction sound coming from the IAC port. Specs- 350 engine, Edelbrock Performer EPS manifold, Holley 4160, TH350 trans (rebuilt w/shift kit), 3. where should TH350 actuator vacuum line connect?. When using a Holley dual sync distributor to utilize timing control capabilities does it plug and play with the Sniper EFI? Almost, You will also need the PART# 558-493 adapter. Reconnect the appropriate vacuum hoses to the Sniper EFI throttle body. 05-09-2020, 08:36 AM Setting up now, I have a fitting in the back of the manifold blocking the brake booster vacuum port on the Sniper. Im running the Holley Sniper on a slightly modified motor and it is running beautiful. These ports will provide ample vacuum port sources for both carbureted and EFI. When using a Holley dual sync distributor to utilize timing control capabilities does it plug and play with the Sniper EFI? Almost, You will also need the PART# 558-493 adapter that will allow it to plug into the ignition connector on the Sniper harness. Capability Range: Moderate Price Point: $ 1 & 2 Barrel 2300 EFI System BBD EFI System 2GC EFI System Autolite 1100 EFI System 4 Barrel Sniper 4150 EFI Super Sniper EFI Sniper XFlow EFI Sniper Quadrajet EFI 4 Barrel STEALTH Stealth 4150 EFI Stealth Super Sniper Stealth 4500 EFI. Attach all vacuum lines, where necessary. Follow along as we make big power out of this 377ci small-block-chevy with bolt-on parts!. If youre running a spring-loaded PCV valve these can cycle or pulse at idle which makes the Sniper think that it has to compensate for it. Remove the plug and attach the vacuum gauge here. com>Holley Carb Vacuum ports. Heavy rainfall caused the Corozal and El Castano rivers near Henri. Holley Sniper EFI Long tube headers Tremec TKO 600 13/12 4 wheel disc brakes Truetrac 3:73 Posi Classic a/c Dakota VHX gages Reply Save Like 1 J. For best results, Holley strongly recommends an in-tank pump. The Holley Sniper EFI has a built in fuel pressure regulator pre set to 58psi so it should (fingers crossed) be a breeze. Use this for PCV, power brake etc. COMPETITION CARBURETORS MODEL 4150 HP SERIES. There is an idle air control valve (IAC) that adjusts air flow beyond what the butterflies do, that contribute to AFR based on throttle position (TPS). Engine vacuum low (8 to 10 inHg) at idle. Is the Sniper smart enough to allow for either, if say, you are running the system on a 207 cubic inch V6 that may require a lower fuel pressure at idle so the set lower limit of pulse width would allow a proper AFR by using manifold vacuum as the source for the regulator boost port?. Three vacuum ports are available on the throttle body. If ping is heard, back the timing down 2 degrees at a time until pinging stops. Venezuela: Disruptions due to flooding ongoing north of Maracay, …. the same one that the brake power booster. Vacuum Ports, 1/8 and (1) 1/4 Pipe . New install, AMC 360, runs bad, datalogs. It gets hot in there and condensation will make problems in your distributor otherwise. Purge line uses manifold vacuum. The FRONT port (plugged) peeks out UNDER the throttle blades (manifold). Ships Today. Holley Sniper PCV location. #1 Vacuum Ports 12-30-2019, 09:20 AM There are three ports on the back of the Sniper. Models Jeep CJ Forum Sniper EFI vacuum ports - Is this set up correctly? Evap canister connects? 3689 Views 4 Replies 3 Participants Last post by whollsee , Jan 30, 2020 uw91 Discussion Starter · Jan 21, 2020 I had my mechanic that has installed these before get mine installed, so I relied on his expertise to set this up correctly. Vacuum Port Side View. View Holley Sniper EFI Self-Tuning Kit - Shiny Finish Bolt on 4150 Flange Carburetor Replacement Throttle body mounted ECU – no extra boxes to mount Supports up to 650hp with Four 100 Lb/Hr Injectors! All of the wiring exits below the rear fuel injector cover, for a completely stealth installation. Lock the distributor, reconnect vac advance to a manifold port or one that pulls vacuum full time even at idle. Vent line from carburetor bowl. With the idle mixture screw removed, the tapered portion is what adjusts the volume of fuel allowed into the engine. Connect your distributor to one of the 3/16 vacuum ports on the EFI. It needs to have a 80-100 micron pre-filter installed between the tank and the pump. Ill use the manifold 3/8 for brake booster, the manifold 3/16 for ignition. Yes, the sniper has a timed spark vacuum port that will operate the vacuum . Connect the brake booster to the runner on the intake. So the rear vacuum advance port is the only one. Holley Sniper EFI System is Easy, Budget. Question Is the Sniper approved for use in marine applications? Answer Yes, Holley does have Sniper EFI Marine certified applications. I chose not to use the aluminum fittings and purchased brass fittings to use instead. The 3/8 vacuum port stub came from the factory capped, but the two smaller vacuum ports are open with no tube stubs or plugs. Connect fuel feed and return hose. Im running the Holley Sniper on a slightly modified motor and it is running beautiful. There are vacuum ports on the Sniper TBI unit itself: http://documents. An easy test would be to set your rev limit to 1500 RPM and test it. I’m trying to make sure the larger threaded port in the front of the Sniper 1250 baseplate (4150, not the Stealth model) is just a plain old manifold vacuum source. The sniper should have a fitting on the rear that the instructions label as brake booster. Holley Performance Products Forums>Rev Limiter. It is located in the north-central region of Venezuela. There is a good description in the instruction for those ports. Im not running a vacuum advance distributor, and my Performer RPM intake already has a vacuum port, so I am assuming theres no need to use any of the three ports on the throttle body?. If the port is truly open to the vacuum, then it will have vacuum. I had the manifold changed since they did the tranny work, so I cant blame them if its connected wrong. Doug Tags: None Danny Cabral Administrator Join Date: Dec 2009 Posts: 32834 Tweet #2. Sniper Official Site: Carb to EFI Conversions, Fuel Systems. The vacuum source for this purge signal will come. I often run the PCV to the rear port and then use the fitting on the intake, behind the carb, to hook up the power brakes. Sniper EFI Bolt-on carburetor style EFI for your classic car or truck. Be sure to plug any vacuum sources not used on both the Sniper EFI Throttle Body and on the Engine. HOLLEY SNIPER EFI TUNING tips, info sharing, ideas. You can use your HEI distributor without its module as a signal to the Sniper for Timing Control on the green and purple wires by connecting them to the HEI pickup coil wires (watch out for polarity). On my 670 Avenger I had 4 Vacuum ports, one for the Brake Booster, one for the PCV, one for the distributor and a full vacuum port I used to for the vacuum canister for my heater controls. Not sure what to do with the three vacuum ports on the back of the Holley Sniper EFI for my configuration. AUTOIMPORT PARTS, LLC is a Florida Domestic Limited-Liability Company filed on March 19, 2019. See Figure 3 for diagram of vacuum ports. I stopped at the transmission place that rebuilt my transmission about a year ago. Both are full vacuum and it doesnt make any difference if its near the primaries or secondary side. HOLLEY SNIPER EFI TUNING tips, info sharing, ideas>HOLLEY SNIPER EFI TUNING tips, info sharing, ideas. Holley Sniper EFI Intake Manifold 835011. Apr 15, 2009 #5 O ORANGE77 Veteran Member Jan 17, 2002 779. Most street Holley carburetors position the manifold vacuum port in this location (arrow) on the carburetor mounting base. The Sniper only has 3 ports, A full manifold port (small nipple), brake booster port and one for vacuum advance on the distributor. Holley Sniper PCV location Cowboy Andy Aug 7, 2021 1 2 Next C Cowboy Andy Farmall Cub Joined Feb 20, 2021 Messages 10 Points 1 Aug 7, 2021 #1 I have installed a 2 barrel Holley Sniper EFI on my 69 Scout 345. com/parts/PRS-1044/ See more 6 Reply Save Like 1 - 15 of 15 Posts BillyGman Discussion Starter · #2 · Nov 21, 2010. One post on a Holley forum recommended the IAC value to be 10-20% for a manual transmission. Not all model 4150’s have vacuum connections, however, some model 4150s are equipped with three vacuum tubes. Sniper EFI Bolt-on carburetor style EFI for your classic car or truck. 700R-4 ProBuilt, Moser 12 bolt with 3. Usually the ported nipple, but the manifold port is ok as well. Not all model 4150’s have vacuum connections, however, some model 4150s are equipped with three vacuum tubes. 5) ThunderHead289 269K subscribers 121K views 7 years ago Carburetor School - Become a Carb Expert: Understanding Settings &. Brake booster/transmission vacuum question. 623 lift/114° LSA camshaft, TFS R-Series. The Sniper Stealth 4500 also features multiple Input and Output options for sensor inputs and switched outputs to control external relays. 92 Ford Mustang GT: 385/6. Holley Performance Products has written this manual for the installation of the Sniper EFI TBI fuel injection system. Ported vacuum would only advance the timing when the throttle plates are open and below the threshold. Vents vapors from the fuel tank into the canister. Here Is The Correct Procedure For Setting An. Low Vacuum on Holley Sniper EFi. Manifold vacuum would advance the timing during cranking and anytime the vacuum is below the threshold to operate and overcome the advance system in the distributor. The fitting is where the brake booster is currently running into the intake. New Sniper install, PCV valve question. Avoid using any 90 degree fittings between the tank and pump. #1 Vacuum Ports 12-30-2019, 09:20 AM There are three ports on the back of the Sniper. Can I use this for a PCV connection? If not, what is its purpose? Thanks!. Specs Service Parts Throttle Position Sensor Part# 870001 $38. Sniper Fabricated Intake Manifold Kits (Carbureted & EFI versions. 44 Idle Air Control Motor Part# 543-105 $71. Introducing Holley EFI V6 Software Updates. what do you mean ported vs manifold? for the vacuum source of the dizzy? I did learn something over at the holley sniper forum -. The PCV valve gets hooked to manifold vacuum, usually through a fitting on the base of a carburetor. One post on a Holley forum recommended the IAC value to be 10-20% for a manual transmission. If you have what you need coming out of the intake then you can just keep them capped with the caps they shipped the unit with. Holley Sniper Vacuum PortsThe Sniper has an internal MAP sensor. Finding a tough to find vacuum leak?. They said insufficient vacuum would be causing the late shifts I described. insights into running manifold vs ported vacuum to settle and disputes. Purge signal uses ported vacuum usually routed thru a CTO, so theres no signal at idle or when the engine is cold. The smaller tube attached to the metering block is timed spark (vacuum provided any time after off idle). Yes, the sniper has a timed spark vacuum port that will operate the vacuum advance. Where to Hook Up Vacuum Lines On A Holley Carburetor. Question I installed my Sniper EFI, but how do I use my kick down for my C4 transmission? Answer. Vacuum port for AT almost always comes off an intake port/nipple. You can set a fixed timing setting to verify that you are actually getting the spark when it is calling for it. Sniper Official Site: Carb to EFI Conversions, Fuel. Attach all vacuum lines, where necessary. Top 10 Sniper EFI Installation Tips from Holleys Tom Kise. Holley Sniper EFI 2300 2BBL HyperSpark Distributor, ECU, and Coil Offenhauser 5585 90° adapter (to line up throttle controls on driver side) Offenhauser 5413A manifold adapter Offenhauser 6208 C-Series Manifold DeLorean Charcoal Canister p/n-101109 Fixed Orifice PCV Valve. Disruptions due to flooding are ongoing across northern Maracay, Aragua State, as of Oct. The Sniper EFI Stealth 4150 Supports Big Power But Remains. I know the regular version has the regulator on the Sniper unit, but according to fuel line layout with the return-less version that inlet plugged. They looked at it and said the vacuum line should be connected to a vacuum port directly on the manifold, ie. com/parts/clp-in38rs/overview/) Then use the large port on the carburetor for your PCV, which is probably a 3/8 hose. At the front of your carb has 2 vacuum ports in the lower baseplate. Holley Carb: Ported vs Manifold Vacuum Advance (CARB BASICS PART 1. In a way, why did Holley even provide it, seems silly really, fitting carb replacement EFI and then still having vacuum advance. Note: Fuel pressure should be checked on the inlet fuel line before initial start up during the fuel pump prime. The Holley Sniper intake has 4 vacuum ports on the bottom and Holley gives you aluminum fittings to use. Aragua State (Spanish: Estado Aragua, IPA: [esˈtaðo aˈɾaɣwa]) is one of the 23 states of Venezuela. Holley Sniper EFI Intake Manifold 835011 Vacuum Port Quantity, None. The Sniper EFI System comes with a built in fuel pressure regulator, factory set at 58. The nipple needs to be 3/8 for proper brake function. Holley Sniper EFI 2300 2BBL HyperSpark Distributor, ECU, and Coil Offenhauser 5585 90° adapter (to line up throttle controls on driver side) Offenhauser 5413A manifold adapter Offenhauser 6208 C-Series Manifold DeLorean Charcoal Canister p/n-101109 Fixed Orifice PCV Valve. 5psi of boost so we teamed up with ProCharger superchargers to put one to the test on Westech Performances engine dyno. Holley Sniper EFI with HyperSpark, Comp Cams, NOS cheater plate with powershot solenoids. Going In-Depth With Holleys Terminator X Stealth 4500 EFI System. Holley Sniper and the PCV valve. An easy test would be to set your rev limit to 1500 RPM and test it. where should TH350 actuator vacuum line connect?>where should TH350 actuator vacuum line connect?. The Sniper Stealth 4500 EFI system from Holley features 8, 100LB/HR Fuel Injectors capable of supporting 800 to 1500 HP naturally aspirated, or 800-1250 HP on forced induction applications. Holley Sniper Intake and Valve Covers Installed. (54) In Stock, Including at a Supplier. Determine where the port enters an area where it will be exposed to vacuum. The Holley Sniper intake has 4 vacuum ports on the bottom and Holley gives you aluminum fittings to use. This is why most OEM EFI pumps are in the tank. The Sniper Stealth 4150 EFI system from Holley features 4, 100LB/HR Fuel Injectors capable of supporting up to 650 HP naturally aspirated or 600 HP on forced induction applications. The companys filing status is listed as Active and its File Number is. So there’s no way that a carburetor spacer will block the vacuum ports. As for vacuum, if the provided ports dont work you could use a spacer with a port or use a port directly from the intake. (66) Make/Engine Basic Operating RPM Range Intake Section Included Throttle Body Bore Size Selected Filters Part Type: Intake Manifolds, Fuel Injected Cylinder Head Configuration: Cathedral Port LS1/LS2/LS6 Filter Results by Vehicle Search New Vehicle Sort Sort By. Holley Carb: Ported vs Manifold Vacuum Advance (CARB BASICS PART 1. Product includes all gaskets and hardware for a hassle-free installation The Sniper intake will only accept EV1 style injectors. This manifold block features 12 1/8th NPT ports that can be plumbed with most common EFI transducers such as the Holley 554-102 0-100 psi transducer. This is no great surprise since these carbs are mostly intended for race applications. This PCV vacuum connection OK?. You also should vent you PCV and charcoal canister to vac. See Figure 4 for diagram of vacuum ports. I looked on Jegs for your intake ( http://www. They looked at it and said the vacuum line should be connected to a vacuum port directly on the manifold, ie. If the trigger is not phased correctly you will be off on everything. 72 O-Ring And Mounting Hardware Kit - LS3/L92 Part# 870003 $26. Not sure what to do with the three vacuum ports on the back of the Holley Sniper EFI for my configuration. mechanic told me to not use a vacuum hose from distributor to EFI. Vacuum Port Side View Figure 3 6. Holley Sniper EFI port ??. This is why most OEM EFI pumps are in the tank. Two 3/16 and one 3/8 for vacuum manifold, booster & distributor respectively. No other vacuum lines needed except your brake booster. To recap, I dont mind running it this way on this manual car, but its not my first choice for an automatic car. View Holley Sniper Stealth 4150 - Black Finish Bolt on 2300 Flange Carburetor Replacement Supports up to 350HP with Two 100lb/hr Injectors Equipped with C4 / C6 Ford transmission kickdown lever as well as. The other two are at the rear: a 3/16-inch manifold vacuum port and a 3/8 manifold vacuum port that works perfectly as a brake booster source. As I wrap up this upgrade I’m not certain where the best location for the PCV hose. 1 on the left and one on the right but one is higher than the other. At the front of your carb has 2 vacuum ports in the lower baseplate. Is the Sniper smart enough to allow for either, if say, you are running the system on a 207 cubic inch V6 that may require a lower fuel pressure at idle so the set lower limit of pulse width would allow a proper AFR by using manifold vacuum as the source for the regulator boost port?. The Sniper line of products are built to take your project to a new level of performance at a great price! Sniper plumbing is high-performance equipment with hand-polished aluminum fittings and high–strength hoses. In business for over 100 years, it would be an understatement to say that they know what they are doing. This basic manual contains the information necessary for the installation of the throttle body, wiring, and sensors. May Gods grace bless you in the Lord Jesus Christ. 00 Purchase Here: holley. (something like this https://www. Tags: None AndyF Senior Member Join Date: Mar 2017 Posts: 3883 Share Tweet #2 11-26-2020, 12:18 PM. Holley Sniper PCV location Cowboy Andy Aug 7, 2021 1 2 Next C Cowboy Andy Farmall Cub Joined Feb 20, 2021 Messages 10 Points 1 Aug 7, 2021 #1 I have installed a 2 barrel Holley Sniper EFI on my 69 Scout 345. The port on the distributor cap would benefit if you connected it to weak vacuum on the air filter assembly. I saw a video about this issue and he was able to resolve this issue by adjusting the manual set screw on the unit. Yes, you can use the PCV and power brake vacuum ports interchangably if you want. Now see if that area is blocked by a gasket or part of the intake. Vacuum port for AT almost always comes off an intake port/nipple. Holley 820111 Silver Low Profile Sniper EFI Sheet Metal Fabricated Int. Holley Performance Products has written this manual for the installation of the Sniper EFI TBI fuel injection system. Maracay, city, capital of Aragua estado (state), northern Venezuela. Is it ported in FRONT of the throttle blade or to the REAR of it? IF its ported to the rear it is manifold vacuum. Holley Sniper EFI 2300 2BBL HyperSpark Distributor, ECU, and Coil Offenhauser 5585 90° adapter (to line up throttle controls on driver side) (~12Hg). Vacuum Port Side View Figure. Where to Hook Up Vacuum Lines On A Holley Carburetor Holley 137K subscribers Subscribe 911K views 13 years ago Carburetor Installation & Tuning Segments Learn More:. the same one that the brake power booster is connected to. Holleys Super Sniper Stealth can support 1,250 horsepower and 21. Quick Question, I noticed the regular Sniper 4150 Sniper is sold with the Returnless Pump by Holley (e. May Gods grace bless you in the. Intake Manifolds, Fuel Injected. Danny Cabral Administrator Join Date: Dec 2009 Posts: 32967 #3 Yesterday, 08:47 AM ABC is correct. 623 lift/114° LSA camshaft, TFS R-Series FTI Comp Ported intake, BBK 80mm throttle body, Holley Dominator MPFI & DIS, Holley 36-1. It is ported into the base of the throttle body so it sees the top of the intake manifold. You want the highest port for your distributor. On my Sniper EFI, there are three vacuum ports in the back. You can lock out mechanical advance with a simple bar across the advance weight posts instead of springs or like this with screws. There is an idle air control valve (IAC) that adjusts air flow beyond what the butterflies do, that contribute to AFR based on throttle position (TPS). The sniper sets timing based on a MAP and RPM table. And 10 micron filter between the pump and throttle body. com/support/carbur In this video, we cover. com>Holley Sniper EFI Installation Tips and Tricks. The vacuum ports pickup manifold vacuum from a slot in the casting which has a passage to the throttle bores. The larger tube at the base of the carburetor provides full manifold vacuum at idle. Installing the fuel pump in the tank results in quieter operation, less chance of cavitation and a. EFE + EGR Delete for Sniper EFI. Get one with a 3/8 port you can use for the power brakes, and one or two smaller 1/4 ports for the vacuum advance, HVAC, etc. If you need another one on the intake manifold, drill & tap for 1/4 NPT on the front or rear of the plenum where the throttle body bolts to. Not sure what to do with the three vacuum ports on the back of the Holley Sniper EFI for my configuration. Ditch the Carb and Go EFI with Holley Terminator X Stealth 4500 and 4150. If open and no vacuum then a gasket or something is blocking it. Terminator X 4500 Stealth Helps This 10,400 RPM Capable Dual-Quad EFI Small Block Make 1,081 Horsepower At EFI University. The threaded vacuum port is a 3/8 size, and is made by Performance Stainless Steel. Good time to switch to a controlled distributor (assuming the Sniper has provisions for it), I went with the GM small cap controlled by my Holley Terminator. Need a vacuum source for the PCV and power brakes. The Sniper EFI System comes with a built in fuel pressure regulator, factory set at 58. 1) Sniper EFI Fabricated LS3 Intake Manifold RPM Power Band: 3,500 – 8,000rpm Intake Runner Length: 5. Has anyone had to install stubs or plugs? Im new to the forum and not sure how to add a pic to this thread. com Holley is unquestionably a leading name in the world of LS performance parts. Be sure to plug any vacuum sources not used on both the Sniper EFI Throttle Body and on the Engine. The numeric IAC value was out of whack (anywhere from 0 to 30%). Vacuum leaks on any manifold connection can cause issues but often an unsteady MAP reading at idle can be traced to the PCV valve. Edelbrock 2176 vacuum source. Holley Sniper EFI 822242 Sniper EFI Fabricated Intake. As for vacuum, if the provided ports dont work you could use a spacer with a port or use a port directly from the intake. Holley Sniper 4150 Stealth & Returnless. The first one is a 3/16-inch ported manifold vacuum at the front, perfect for a vacuum advanced distributor connection. We recommend at least a 3/8” feed line and 3/8” return line. The front ported vacuum port pulls 20 of vacuum, the rear manifold port pulls 7-10 of unsteady vacuum. Usually Td into the PCV purge line. Holley Carb: Ported vs Manifold Vacuum Advance (CARB BASICS. Purge signal uses ported vacuum usually routed thru a CTO, so theres no signal at idle or when the engine is cold. Holley Sniper EFI Installation Tips and Tricks. 550-516D), but not the 4150 Stealth version. Sniper EFI Tuning & Tech. The threaded vacuum port is a 3/8 size, and is made by Performance Stainless Steel. Most intakes usually have a port in the front and/or rear runners that you could put a fitting into to hook the PCV or power brakes vacuum line to. Most street Holley carburetors position the manifold vacuum port in this location (arrow) on the carburetor mounting base. The Sniper line of fuel pumps, regulators, and filters make Sniper a one-stop shop for a complete fuel system overhaul. The system has a total of 20 minutes of drive time, probably 2-3 hours of idle time between me setting things up and troubleshooting. Total (initial and centrifugal) as well as load based (vacuum) are built into the table. See Figure 4 for diagram of vacuum ports. Im getting ready to put a Sniper on a customers 67 Mustang, stock 289/C4. Lock the distributor, reconnect vac advance to a manifold port or one that pulls vacuum full time even at idle. You will need to connect the Evap can and brake booster vacuum ports here. Models Jeep CJ Forum Sniper EFI vacuum ports - Is this set up correctly? Evap canister connects? 3689 Views 4 Replies 3 Participants Last post by whollsee , Jan. pdf (Holley Sniper EFI Instruction Manual - See Page 7). On my 670 Avenger I had 4 Vacuum ports, one for the Brake Booster, one for the PCV, one for the distributor and a full vacuum port I used to for the vacuum canister for my heater controls. The vacuum ports, all on the secondary side clean up the look, but placing the ported spark on the secondary, even at 1:1 has got to be late compared to the fitting being on the primary side where it SHOULD be. Using the Holley EFI software (LINK), look at where the live cursor moves to during this occurrence, and manually tune that area of the Base Fuel Table (enrich or lean) & Base Timing Table (optimize ignition timing). Vacuum Port Side View. The sniper sets timing based on a MAP and RPM table. Ford 302 vacuum tree, thermostat housing. Reconnect vac advance, the timing should be around 20 - 24 degrees before top dead center.