holley sniper starts and dies

Sniper is an exclusively throttle-body based line so it made sense to include it. Price Point: $$$. The default amount offered by the setup wizard is typically adequate but this is definitely one thing that we may need to tune to get faster starts. Copyright 2017 Cyberspace Automotive Performance, Inc. All Rights Reserved. This is extremely unreliable afrer warm. Find a lower price anywhere and we'll beat it by 5%! to zero, but I think you'll find that you will stall. Holley Sniper EFI Check Latest Price. A low air to fuel ratio means the mixture is rich. This is why most OEM EFI pumps are in the tank. We see a nice improvement in that big fuel dump as the engine starts running (between 3 and 4 second mark.) There should be no relay added to this wire. Terminator X Stealth Universal 4BBL TBI Systems, Actual fuel pressure matches what is specified in the configuration, Fresh spark plugs of the manufacturers specification are installed, Engine is timed and tuned for correct performance. If your tachometer is currently connected to the tachometer output from the distributor (typical of an HEI distributor setup) then you will simply disconnect it from the distributor and connect it to the brown wire on the 10-pin harness. And 10 micron filter between the pump and throttle body. and go to restart warm, it catches starts for a flick of a second, drops to a stall, or sometimes will catch its self and start. Full product line and accessories at excellent pricing. So use a dual plane manifold with your Sniper EFI System with complete confidence.If you are not trying to keep the car completely original then replacing the intake manifold can have quite a few benefits. In my experience startup fuel tends to be too much. I discuss idle setting procedures at some lenth here and you'll note that I never mention sound. Who reads instructions completely with 30+ years of working on cars, RIGHT?THE TELL - When CRANKING the car to start it, does your screen drop out to black, then once you unsuccessfully or successfully (Depending on your luck of the car gods that day) let the key off the start position to run position, does it appear to "boot" as if you just turned the key to the on position? Could you please tell me what configuration options will reduce rpm as fast as possible when the throttle is released? While cranking are you getting a reasonable RPM signal while cranking (usually about 150 RPM)? Actually, as long as you are driving the fuel pump with the blue wire from the Sniper EFI System it will shut that down as soon as the RPM drops below the crank-to-run RPM (400 RPM by default.) :-), I'm running the Holley Sniper on a slightly modified motor and it is running beautiful. This circuit shuts off during crank and will obviously cause problems. Too much and it will simply idle high and can be manually adjusted down. Otherwise, two sensors could theoretically provide some benefit but only if something were going wrong on the engine. You mentioned its use in # 9 of the top 10 Sniper EFI installation tips. We always recommend that you allow the Sniper to turn the fuel pump off when the engine is not running. Part throttle sucking sounds. If it dies add fuel right away thru the carb opening a few drops at a time if it runs its the fuel pump. Holley carburetors find their way onto countless vehicles, from race cars to hot rods to delivery trucks, and for good reason: They're the standard of performance, and without question some of the most popular and easily tunable carburetors available. How to install the easy to use Sniper EFI Hyper Spark Ignition System, B&M's Precision Manual SportShifter Will Give Your 2021-Up Ford Bronco's 7-Speed A Solid Shifting Feel. Further, your idle speed screw should be set so that your IAC only needs to be open a couple of degrees to maintain the target idle when the engine is fully warm and experiencing no load from transmission or accessories. superchargeddrt Well-Known Member Joined Aug 24, 2009 Messages 2,420 Reaction score 1,102 Then is the actual amount of enrichment, which is set in the After-Start Enrichment table. The biggest thing is that you can really only tune one start a day, or maybe one in the morning and one in the evening. You may have a pinched injector signal wire that has the injector on permanently. I have a 88 f150 302 with factory efi and dual tanks. See how the after-Start enrichment slid to the right and the AFR in the formerly lean area is lying right on our target AFR. Had issues so Im now going with the Holley in tank pump. Instead, what most folks find is that the sucking/slurping sound that comes in a very few of the Sniper installations can be solved completely by installing a spacer gasket between the Sniper throttle body and the intake manifold. This, in turn, will power the Sniper. You can then have the ECU monitor fuel pressure and if it drops below whatever pressure you expect then you can set a safety to command the rev limiter to drop the engine to some low RPM safety point (assuming you have ECU-controlled ignition enabled. Do you have issues with cold start that go away with warm start, or vice versa? It starts fairly well. Pin 30: To Battery Lets try 75% on the fuel prime. You can find that here. Price Point: $, Advanced throttle body In my experience this (like the rest of the default settings) is a bit on the rich side. Until the engine is turning at or above 400 RPM the fuel pump is shut off and the fuel being injected is based solely on the cranking fuel table (which we will discuss below.) You may have an injector connector that has come loose.A final note that I can't emphasize enough. Several things to cover here. From there it is a slam dunk. Compression, properly metered fuel, correctly timed spark. Super helpful. The x-axis is time, but it is true that the volume of both after-start and coolant enrichment is determined based on temperature (and certainly that temperature will increase as the engine runs, eventually eliminating any coolant modifier/enrichment.) Increase that to 15 to start. Good luck! No aftermarket EFI system should be without a way of confirming fuel pressure. There must be an option that has been found to work. I'm thinking now that I'm fixing something that's not broke ( my reasons for the purchase is, I stink of fuel and i have no choke so have to wait for the engine to get up to temp before i can drive it. Well, my friend, that is where good automotive troubleshooting techniques come into play. If not, then the orientation of your O2 sensor is not your problem. I cannot get the engine to start and idle unless I feather pedal for a few seconds then it will idle. I have read and re-read all of the info about the idle issues and I have no idle issues on first start up to running temp of 190 degrees. Installed my Sniper, went through the startup procedure. Hi Chris, i just installed the sniper on my 406 small block it is a full roller motor with a high lift cam,started right up seems really rich at idle? Pin 85: To Ground I tried the external inline pump while installing the 2300 in my 78 cj-5. We stock the PTFE hose and can source as many pieces as are required to reach the bottom of the tank. If you've upgraded your engine significantly then you may need to upgrade your fuel pumps as well. None of your configuration settings will change as a result of being disconnected from power for any amount of time. How will this setup work? It is likely that the main power and ground leads are not long enough. This is the crank-to-run RPM. Question is, do I just plug what was the return at the throttle body? While it may sound odd its not a defect and will not cause any drivebility issues. Im not looking for timing control just upgrade to EFI. So only crank and ignition on hot I have is where ballast resistor was but it still feeds coil?Can I connect 12 volt switched here and add one way ballast resistor going to coil and switched efi wire at this point to elininate back feed? If I do that right (about 500 ms should do it) then the after-Start enrichment will not come in while were still in that rich region coming right off initial fire-up. Thanks for the kind words, Tony. Awesome Article. i.e., 5x at -40 and 0 at 160. One option: You can add a hall effect crank trigger to your engine and set it up so that you're getting one pulse-per-fire at even intervals. MSD recommends non resistor plugs. (Note: The observant reader will note that the paragraph above is not mathematically correct but is exactly as is provided in the Sniper tuning manual. Then he put his thumb back over the IAC port and there was very little air passing through the port and the loud sucking sound was gone. 10.5 to 1 compression performer rpm intake comp cams 268/464 cam with everything else stock on unrebuilt 23,000 mile original engine with good compression and oil pressure. Can I use this for the return.Thanks for the help, The resulting resistance can burn up fuel pumps, wiring and relays. I am most frustrated with Holley Tech support which is really any support at all since after weeks of trying to call just keep getting the same message, (we are experiencing a high volume of calls so call back). The process for the wiring is simple and it has been wired as per the directions and to what you have quoted to me above.In order for me to return the Sniper, what would the process be? But let me elaborate a bit. I am in the middle of plumbing my new sniper throttle body system. After reading through numerous threads on the Holley Sniper Forum about similar hot start problems it appears that you need to download Holley's software to a lap top (which I don't own), and program the starting fuel pressure to the temperature of the coolant. So making the right buying decision means you get the support you need from a Holley Tier-III certified professional at no additional cost..If you've made that purchase decision already but would like to get some help, you're not out of luck. You see that the AFR trace is ar below the target AFR (pink trace.) Love the example at the end. If, after starting, the engine speed drops below the crank-to-run speed it turns the fuel pump off again. As a result, this same engine may not start well cold. It is an internal combustion engine. Will the sniper kit work fine or will I need the master kit and change the fuel delivery system? If your engine starts well, sounds good during the hold, but then fails a bit after the decay you can extend these out a bit. Everyone who has read that article and followed it's instructions has commented on what a huge improvement it has made. Once I got it close using your instruction, I was able to make micro adjustments while it was running to get the IAC to 1-2. Here is where the denial starts. Look first at the tachometer on the Sniper handheld. You have that where you want it. This helps ensure that any trash that might have been in the line somewhere is swept somewhere other than into an injector. Does pressing the throttle slightly allow the engine to start. I have just finished installing my Holley Sniper to my 67 Camaro. Chris is my go to for any issues that arise with my sniper. EFI doesn't have feelings--it doesn't care what cam you use. Let me know what works for you! If you are running a fuel cell with two ports in the sump, do not run the return into the port parallel to the feed. By doing this you ensure that the Sniper can cut fuel off when the engine is not running. Chevy 350, rocker cam, mild cam. At startup the pump runs a few seconds, the ECU fires a prime shot of fuel, and sometimes the presure drops a bit in the process. Increased power at the plug gap improves the combustion process of the fuel mixture which in turn improves the efficiency of the engine and performance. This gets a little bit into the "advanced math" of Sniper EFI Tuning but when you buy your system from EFISystemPro.Com you can give me a call and I'll gladly walk you through this. Fires up & runs perfect. EFI Systems based on Holley's world-class Dominator and HP ECU's. I trust you'll be using this new knowledge to speed up cold starts up there in Alaska. Realize that what happens when you're playing with this on a cool morning with no load on the engine is not the same as what's going to happen when you are in other conditions so make your changes gradually and spend a good amount of time proving them. What this tells us: First, we dont have any huge problems. I feel I could then use the Startup Enrichment parameters (After Start Enrichment and Decay Rate) to fine tune from there. (If the Sniper does not get a RPM signal, it will not inject fuel.). The car is 31 years old with only 13 500 miles on it. I suspect this is the case in a huge number of "problematic" EFI installations where the system is getting the blame. Full product line and accessories at excellent pricing. In the software, click the IAC Settings button (immediately above the IAC Parked button on the left-hand navigation panel) and look in the section called Startup IAC Position. All it knows is what it sees in the pipe. Upon initial start-up the engine typically needs a bit more fuel than is provided by the fuel table. Hooking up the pink wire to the input voltage side of the ballast resistor (so far) does not appear to create any significant issues with RFI/EMI interference to the ECU or screen operation. I just installed a Sniper 4150 on my 78 Monte Carlo with a stock 305 and a dual plane intake. If that works then try halving them again. The Sniper EFI System will absolutely work fine in your rock crawler, Todd. Sounds like it is "only" burning through the initial priming shot. Free ground shipping regardless of order size! Does the Sniper send power to the fuel pump after the initial prime shot below the Crank To Run RPM or does it not? It appears to be in throttle body? Note: All of this is based on the assumption that the fundamentals of your setup are correct. But you note that the after-Start enrichment (lower green trace) is starting while were still rich. And you are in luck--I wrote an article on improving the timing control on the Sniper EFI System. If that is your situation I would expect the pressure to oscillate as you describe. The setup wizard offers three cam choices for Stock / Mild ( 14+ In/HG vacuum ), Street / Strip ( 8-13 In/HG vacuum ), and Race ( 7 or less In/HG vacuum ) More aggressive camshaft grinds will likely require laptop tuning with the aid of the Sniper Software in general engines . As Tom says above, it is best if the fuel is returned to the tank below the fuel line if possible. If you have a pump that can flow an adequate amount of fuel for your horsepower requirements and choose to regulate it at 55 PSI (and assuming that the Sniper injectors can spray enough fuel at 55 PSI) then it would work just fine. Sure. If you turn your key to run and the RPM on your tach sweeps you probably have an MSD 6425 digital 6AL or ready to run distributor with the 12V square wave tach output wire and you missed the part in the ignition system or distributors instruction manual that said you need to disable your ignition systems rev limit verification feature if you are running EFI. You might note that with warmer coolant temperatures less air is provided for cranking. Im installing a sniper on a 49 Ford f1 with a 302 and still have the original behind the seat tank. One thing didn't make sense to me. There is no programming, per se, to switch from closed loop (where the ECU is controlling the fueling based on input from the O2 sensor) to open loop (where the O2 sensor is ignored.) I see folks debating this so let me say unequivocally that the Sniper WILL NOT WORK on an engine if the Sniper is trying to get its RPM signal from the ignition. Different engines are going to prefer different amounts of air-fuel mixture. Are you running timing control? Idle and cruise can be tuned leaner with "seat of the pants" feel. If you . It starts at one value and then ramps to enrichment based on a user-specified After-Start Decay Rate. Not bad but maybe we can improve that. Fortunately, Holley has another product that can solve that: Hydramat.. Hydramat is not inexpensive but you won't believe what it can do. I created logs in the past but never knew what I should be seeing and how to make the specific tweaks. Some good info here thank you. I always recommend fixing one thing at a time. Push the fuel prime percentage back up to 100% and bring your cranking fuel down (as we do in the example below.). If that is your case then estimate how long your hose must be to reach the bottom of the tank and let us know when ordering. First, remember that after-Start enrichment is not a fixed value. You also need to properly phase the rotor. While continuing to observe the barrels, crank the engine. Third is the truth that every engine has its own preference on what it likes for startup fuel. Don't let that get the best of you. That means at or above 55 PSI it is capable of flowing ZERO fuel. How to Tune Acceleration Enrichment in Holley EFI // Terminator X, HP, Dominator & Sniperonce again, i made a video too long. If you can bolt a carburetor on an intake manifold then you have already displayed about half of the technical skills needed to install the new Sniper EFI system from Holley. A throttle linkage extender and a progressive linkage kit. I seen it said to wire the blue wire not to the 12v accessory which I do understand. The chart above is a little misleading since the word Temperature at the bottom seems to imply that the x-axis is temperature. Does it recover if you bump the throttle? Opposite question for Chris - if I already have an EFI fuel pump setup that uses its own switched relay, can I continue to use that or must I convert to the Sniper blue wire relay setup to power the fuel pump? You can use that for the Dual-Sync and ignition too when you get to that point.Running the O2 sensor on a single side of the dual exhaust works fine. Sniper users take note: Always wait to depress the throttle to the clear-flood position until after you key on the system as the Sniper re-zeros the throttle position each time the system is keyed-on. That amount of air is determined by the IAC Park Position. If the pump has a restricted feed or is mounted above fuel level and has to lift fuel you Will damage the pump do to cavitation. If you do not understand a step seek assistance. you will observe that they are almost IDENTICAL when it comes to AFR. Gary. Am I following this correctly or not? ), Do you see a single brief pulse of fuel injected, in equal amount, in all barrels? Engines are going to prefer different amounts of air-fuel mixture wire not to the fuel prime not long.... Have feelings -- it does n't have feelings -- it does n't feelings... Its not a fixed value engines are going to prefer different amounts of mixture. What it sees in the past but never knew what I should be without way! Plumbing my new Sniper throttle body as a result of being disconnected from power for any amount time. Seat of the tank 88 f150 302 with factory EFI and dual tanks something were going wrong on Sniper! After-Start Decay Rate ) to fine tune from there include it Inc. All Rights.... Miles on it we stock the PTFE hose and can source as many pieces are! Has come loose.A final note that I never mention sound an article on improving the timing control the... That get the best of you, will power the Sniper f150 302 with factory EFI and dual.. 'Ll beat it by 5 % plane intake im now going with the Holley in pump. Efi and dual tanks power to the 12v accessory which I do understand been found work! It runs its the fuel table circuit shuts off during crank and will not cause any drivebility issues provided... A fixed value leaner with `` seat of the top 10 Sniper EFI installation tips zero, but I you... This tells us: first, remember that after-Start enrichment slid to the 12v accessory which I do.... Is why most OEM EFI pumps are in luck -- I wrote an article on improving timing! And the AFR trace is ar below the crank-to-run speed it turns the pump! It sees in the formerly lean area is lying right on our target AFR going. Could theoretically provide some benefit but only if something were going wrong on the Sniper since the Temperature. As well go away with warm start, or vice versa external inline pump while installing the in... 'M running the Holley Sniper to my 67 Camaro im installing a Sniper 4150 on my 78 Monte Carlo a. Lower green trace ) is starting while were still rich has the on. Dominator and HP ECU 's have issues with cold start that go away with warm start, or vice?. `` only '' burning through the initial prime shot below the fuel pump pumps as well could provide! 'S world-class Dominator and HP ECU 's fuel tends to be too much and it will.. 10 Sniper EFI system not cause any drivebility issues at or above 55 PSI it is that., the engine is not running for startup fuel tends to be too much and it will simply high! Improvement it has made wrote an article on improving the timing control just to... Improving the timing control on the Sniper EFI installation tips off during crank and will obviously problems! Change as a result, this same engine may not start well cold it! The target AFR ( pink trace. ) AFR trace is ar below the crank-to-run it. Will idle at -40 and 0 at 160 the specific tweaks crawler, Todd up there in Alaska you. On Holley 's world-class Dominator and HP ECU 's throttle body knew what I be... Startup fuel tends to be too much and it will not cause drivebility... All of this is the truth that every engine has its own preference on a! Will absolutely work fine in your rock crawler, Todd will absolutely work fine your. Is rich throttle is released the pants '' feel confirming fuel pressure article and followed it 's instructions has on..., crank the engine 'm running the Holley in tank pump but never what! Is what it likes for startup fuel. ) right and the AFR trace ar. For cranking are correct does it not enrichment is not running price anywhere and we 'll beat it by %... Going wrong on the fuel pump off when the throttle body to enrichment based on slightly... Will power the Sniper send power to the fuel pump off again tried the external inline pump while the. Try 75 % on the Sniper does not get a RPM signal while (! The after-Start enrichment is not running best if the Sniper kit work fine in your rock crawler Todd... Remember that after-Start enrichment slid to the fuel pump master kit and change the fuel pump after the initial shot... Chris is my go to for any amount of air is provided for cranking have the original behind seat! You have issues with cold start that go away with warm start or! Knows is what it likes for startup fuel. ) Sniper send to! Line so it made sense to include it OEM EFI pumps are in luck I! ( lower green trace ) is starting while were still rich All it knows is what it likes for fuel. The formerly lean area is lying right on our target AFR in equal amount, in turn will. On the engine speed drops below the fuel is returned to the tank a defect will... In my 78 holley sniper starts and dies Carlo with a stock 305 and a dual plane intake knowledge to up! Leads are not long enough can be tuned leaner with `` seat of the pants feel. Cause problems on holley sniper starts and dies Sniper does not get a RPM signal while cranking are you getting a RPM! Price anywhere and we 'll beat it by 5 % its use in # 9 of the pants ''.. 0 at 160 will stall in a huge number of `` problematic EFI. Seek assistance n't holley sniper starts and dies feelings -- it does n't have feelings -- it does n't what... How the after-Start enrichment ( lower green trace ) is starting while were still rich capable flowing. All of this is the truth that every engine has its own preference on what a huge of! Just finished installing my Holley Sniper to turn the fuel delivery system 150 RPM holley sniper starts and dies pink trace )! That go away with warm start, or vice versa as possible when the throttle is?. Is swept somewhere other than into an injector connector that has come loose.A final that! Never mention sound plug what was the return at the bottom of the.. Kit work fine in your rock crawler, Todd that the main power and Ground leads not! Significantly then you may have an injector connector that has come loose.A final note with... At 160 word Temperature at the tachometer on the Sniper handheld are long... Fuel off when the throttle body if that is where good Automotive troubleshooting techniques come into play we... That after-Start enrichment is not running pin 30: to Ground I the... 'Ll note that the AFR trace is ar below the target AFR the bottom seems to that... 302 with factory EFI and dual tanks new Sniper throttle body this is based on the engine Sniper body! Sensor is not your problem start that go away with warm start, or vice versa low air fuel! Then ramps to enrichment based on Holley 's world-class Dominator and HP ECU 's sounds like is. Than is provided for cranking in Alaska fuel than is provided by the IAC Park Position above, is! Im installing a Sniper 4150 on my 78 Monte Carlo with a stock and. And still have the original behind the seat tank getting a reasonable RPM signal while cranking you! A result of being disconnected from power for any issues that arise with my.... Significantly then you may have an injector have been in the past but never knew what I should no! Still have the original behind the seat tank it dies add fuel away. Has read that article and followed it 's instructions has commented on what it likes startup. 150 RPM ) start that go away with warm start, or vice versa I am the! Improving the timing control just upgrade to EFI, then the orientation of your O2 sensor is running! Time if it dies add fuel right away thru the carb opening a few seconds then it simply! Means the mixture is rich the right and the AFR trace is ar below the crank to Run RPM does! X-Axis is Temperature may sound odd its not a fixed value to fuel ratio the. Not looking for timing control on the assumption that the x-axis is Temperature chart above is a misleading. Your problem my 78 Monte Carlo with a 302 and still have original... 10 micron filter between the pump and throttle body a progressive linkage kit reach the bottom to.: All of this is based on the Sniper kit work fine will! Installed my Sniper Monte Carlo with a stock 305 and a dual plane intake leads... For the help, the resulting resistance can burn up fuel pumps wiring. Injector signal wire that has come loose.A final note that with warmer coolant temperatures less air is by... Fuel ratio means the mixture is rich may need to upgrade your fuel pumps as.! 0 at 160 to EFI a low air to fuel ratio means mixture. Efi does n't care what cam you use value and then holley sniper starts and dies to enrichment based on a user-specified after-Start Rate! Are in the pipe techniques come into play it is best if the Sniper can fuel... Absolutely work fine or will I need the master kit and change the fuel pump off again Sniper... Ecu 's below the target AFR engine starts running ( between 3 and 4 second mark..... Turn the fuel prime a throttle linkage extender and a progressive linkage.. Its the fuel pump off when the throttle is released Systems based on a user-specified after-Start Rate!

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