But I have never heard of anyone else who has had success doing this. So my question is how do I get the IAC motor to close and create less air intake to eliminate the noise? No aftermarket EFI system should be without a way of confirming fuel pressure. Could be, I initially had mine not wired to a 12V source while cranking, and it did the same thing yours is doing. Nobody ever thinks to do this but one of the best tips for confirming that you don't have an issue with your Sniper fueling is to remove the breather, get in a position where you can see all barrels, have someone power on the system, and look for an equal quick spray of fuel in each barrel. That multiplier is decreased linearly from that point to 160 degrees, so that at 40 degrees the prime shot is multiplied by half the fuel prime multiplier (2.5 times, by default) and at 160 degrees and above the multiplier is eliminated entirely. Pinched or Burnt O2 sensor Wiring: Keep it high, tight, and safe. Price Point: $, Advanced throttle body injection systems capable of transmission control and more. My car idles beautifully @ about 800rpm. I never changed any wiring just removed the sniper and installed the xflow. So, yea it gonna ALWAYS be hard to start!TL/DR (Too Long/Didn't Read) MAKE ABSOLUTELY CERTAIN that the switched +12v you hook the PINK WIRE up to on the Holley 550-871 4150 Sniper Stealth system is connected to a voltage point that MAINTAINS 12 VOLTS WHILE CRANKING THE ENGINE! Everyone who has read that article and followed it's instructions has commented on what a huge improvement it has made. Do you see an issue with this? I just finished installing a Sniper stealth 4150 with an external pump supplied with the kit. Figure out what it's not getting and the find out why. Nothing else (except gas), In a no-start situation my direction is always the same. How Sniper EFI Helped Get The Andersons' C10 Project Back On Track. Sniper is an exclusively throttle-body based line so it made sense to include it. At the bottom you'll see AE vs TPS RoC Blanking. 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. Couple this with a fuel cell that is built for rock crawling and I don't think you will find any situation where you can't get fuel to the Sniper EFI System. That amount of air is determined by the IAC Park Position. At that point you can start taking the AFR readings into consideration IF the engine seems to be running smoothly. Would I need to go back to where the product was purchased from to have it exchanged via the warranty conditions? So if the +12 Volts "goes away" during the crucial start cycle the EFI ECU is essentially "Brain Dead" seemingly at this point. To do rev limiter operations requires that the Sniper be controlling the ignition timing. Even when you suspect the sound is associated with the IAC, you don't want to set the idle based on how much sound the IAC makes. If I go to ignition switch it is the same wire just 2 away. Direct to the battery means to the battery. Power glide with 1.80 first gear, 6,200 converter. Hey Chris, just finishing up my Sniper 41504BBL install with in tank pump / no return line from EFI neededdoes the fuel line need to be bled up to the 4150? Fires up & runs perfect. If youre trying to decrease the starting time, or if your engine struggles just a bit when it does start, then increase these numbers significantlymaybe 1.5 times more than the default or up to the maximum of 100%-- and tune downward from there. Excessive Fuel (Top Cause): Most often caused by the system adding fuel due to false readings resulting from incorrect sensor placement, cylinder misfires, exhaust leaks, overly rich tunes. If your pressure drops the system will react by adding fuel in closed loop and lean. seems to be running rich at a idle. Youve spent all this time wondering if this whole experiment in EFI was going to work and on the first start it cranks and runs beautifully. Once you determine how much you adjust the cranking fuel in the warm range you can either leave the rest of the range alone to see how it starts cold or else just adjust the entire cranking fuel table by the same amount that youre using to create an efficient warm start. That's where I would start. Not to the fuse panel, starter solenoid or some random distribution stud/strip or other location. Compression, properly metered fuel, correctly timed spark. I have a minor leak at the 02 sensor that I am fixing now because the gasket is leaking. Great job implementing what I've written! And 10 micron filter between the pump and throttle body. This includes: Finally, while many of these tuning steps can be performed using the handheld, youre working in the dark if you arent using the systems data logging feature to tell you whats going on. Capability Range: Advanced If you turn the ignition off and back on, & crank it, it will start & die again. Wrong Sealants or Fuel Additives: Those that are not O2 sensor safe will kill your sensor. 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. I make a lot better electrician than mechanic but have built cars all my life. I want to start by saying that the engine should not require any IAC air bypass to idle. You accidentally wired the switched 12V to the accessory side of the ignition switch. Do you have fuel pressure? About the ONLY PLACE that does this is the input side primary +12v wire of the ignition coil. Most important!!! Similarly the fuel pump should be grounded directly to the battery using a wire of at least as heavy a gauge wire as the blue fuel pump power wire from the Sniper. Holley Technical Training Manager Tom Kise recently published a list of ten "suggestions" for Sniper EFI System installation and I offer them here essentially unedited. Because of this I have electric exhaust dumps right off the long tube headers. Bradley Iger. Ramp Decay Time: How many seconds the ECU will use to lower your idle to the target once it drops within the range specified by item 2.). Chris is my go to for any issues that arise with my sniper. Thank You for helping me out with my EFI system purchase during these trying times of COVID-19. I have a 88 f150 302 with factory efi and dual tanks. Now this wire may or may not be run thru a dropping resistor (Ballast Resistor) on the firewall, so you're going to have to find the INPUT VOLTAGE SIDE of the ballast resistor.Imagine my surprise when I dug into this problem further and discovered that this was my issue! 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. There should be no relay added to this wire. I have the 12-1800 dual holley pump also. Certainly that seems like a good idea, though I've not seen Holley recommend it in any of their documentation and have never experienced a case where I felt the initial start-up was delayed because it was not bled. I still have the lound sucking air sound. In a nutshell, you do the following:1. Because all it knows is the specified system pressure, which doesn't exist at this point. My situation, although related to start up, is somewhat different. Free ground shipping regardless of order size! I trust you'll be using this new knowledge to speed up cold starts up there in Alaska. Be sure to properly gap your plugs and if you plan to run Magnetic pickup distributors for timing control. I'm glad that worked for you! Thanks. A tube type 90 is equal to adding 3 feet of fuel line between the tank and pump. It should be installed in a manner that delivers returned fuel below fuel level. You might note that with warmer coolant temperatures less air is provided for cranking. Super helpful and knowledgeable. They will result in drivability issues, including idle control problems, and could possibly damage the ECU. Have you ever watched a post nuclear apocalypse movie? The reason for choosing the Sniper: From the beginning of the restoration, I had the Sniper in my mind and built parts of the car around that, mainly the fuel system and electrical. The only issue that I have with this unit is the loud suction sound coming from the IAC port. classic car or truck Copyright 2022 Holley Performance Products, Inc. All right reserved. 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. Hi Chris,Thank you so much for your quick response to my query. Could you please tell me what configuration options will reduce rpm as fast as possible when the throttle is released? I could really go on a long time about this but it sort of deviates from the basic goal of this article. Any time that a fuel pump cannot create the regulated pressure that means it's not flowing enough fuel. Capability Range: Professional Because the sensor gets fouled and exhaust gasses cannot get to the sensing element leaving oxygen as the only thing present for it to read, hence the dead lean reading. Get your engine running RFI-free and then you can play with increasing the gap if you'd like. Idle and cruise can be tuned leaner with "seat of the pants" feel. Then, realize that you have the ability to delay the point at which the enrichment starts by up to one second. Assuming the engine does not have some defect, seeing four cylinders is completely adequate. You'll note that the pressure drops at that point. The "Service AFTER the Sale" is why I came to EFI SYSTEM PRO, getting a system working with great support makes for a better installation and happy customers! MSD recommends non resistor plugs. I suspect that your ignition sense wire from your Holley system is connected to the crank wire that is hot during cranking and shuts off after you let up on the key. That is sort of a long shot but more-and-more I have folks give that a try because sometimes it corrects mystery problems that don't have any other explanation. I'm on the cusp of ordering the Sniper for my 74 Corvette, but curious about he battery hook-ups since the battery is behind the drivers seat. Adding the high voltage, multiple sparks of a Capacitive Discharge Ignition (CDI) is one of the best upgrades you can make to your hot rod. Once engine is warmed up been driving for awhile. Much appreciated! Free ground shipping regardless of order size! Thats what we want, right? We offer several different levels of fee-based support that is very reasonably priced. 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. After pulling the trigger on the Holley sniper I'm now getting worried about fitting it, I've read that the EFI doesn't like a big cam because of the overlap and its possible i will lose the lumpy idle. What do I need to do to rectify this issue? Activate Advanced Tables2. I figured it would be minimal. 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. Is the sniper compatible with my distributor? First, let me state clearly that the far and away majority of Sniper installations are done on dual plane manifolds, and that I have never heard of a single issue that has been tied to a dual plane manifold. Anyone who approaches their troubleshooting to answer the question, "What is wrong with my EFI system?" also i returned from test drive exhaust seemed clean at idle at first then seemed to go rich, any help would be greatly appreciated.Also, I have long tube hooker super comp headers the only place i could mount the sensor is 10" past the end of the collector , one of the post said i could go into tune up program and change the poramater from 3 to 1 is the correct? Thanks. Sounds like it is "only" burning through the initial priming shot. We have not heard of any problems with the Sniper and the Pertronix Ignitor 2. 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.) Be sure to watch the video embedded at the link above. You may have an injector connector that has come loose.A final note that I can't emphasize enough. Do I still need the holley 12-753 30 amp relay. That added fuel is called after-start enrichment. Not some generic pump as some have speculated. It drains the battery almost dead then will fire up. I have just finished installing my Holley Sniper to my 67 Camaro. Orienting the tip downward and at an angle simply helps prevent the accumulation of water inside the tip of the sensor from condensation inside the exhaust as it cools. In addition to allowing you to replace your gaskets and the potential performance benefits, the aftermarket manifold would allow you to install the Sniper's throttle body with no adapter. Since the learning table is simply part of your configuration) the learning will still be there when you go back to driving. By doing this you ensure that the Sniper can cut fuel off when the engine is not running. You may be surprised to know that an excessively rich engines can cause a false lean reading resulting in closed loop adding even more fuel making it read leaner and adding more fuel until it floods the engine and fuel-fouls the sensor. Do you get an RPM reading on the handheld while cranking? Too little opening and the engine risks not having enough air to start. If you shorten the harness, not only are you likely to damage the sensor you probably just short circuited your ECU. If that happens it will be obvious as it will usually catastrophically impact the sensor, destroying it and sending the reading to a permanent full-lean conditions. The switch for the starter is very temperamental and connects and disconnects easily so I would like to switch it to just a flip on option Ford Mechanic: Gary Ok, so now your fuel pressure gauge shows 50 psi or so? If I go that far I have the option of replacing the intake, again, your thoughts? Everyone else was backordered several months. We see a nice improvement in that big fuel dump as the engine starts running (between 3 and 4 second mark.) Would it start & quit like that if the switched wire wasnt working? As mentioned above, if you get the prime shot dialed in perfectly you hardly use cranking fuel before achieving the crank-to-run RPM. I really would like to replace the intake gaskets. Avoid using any 90 degree fittings between the tank and pump. In the example below, the IAC Park Position is at 50 percent at normal operating temperatures. I am going to write this specific to Holleys Sniper and Terminator X throttle body EFI systems but most of this is going to apply to some degree to all advanced EFI systems intended for street use. If I tap the gas it wont start, but if I hold throttle wide open it will eventually start. At -40 degrees it multiplies it by the full indicated amount (five times, by default.) check out the. :-) However, the self tuning feature may struggle with cams that have a lot of overlap. Hello Chris. Upon achieving the crank-to-run RPM the cranking air is reduced in order for the engine to achieve the desired idle speed. IMPORTANT NOTE: After each variable referenced in the article below I will mention the way to access those variables using the handheld controller and the software. transmission control and more. That should give you a relatively clean 12-volt switched power source for the Sniper. And it may have improvedor it may have gotten worse. Note that while you can see an air-fuel ratio trace (sort of rust-colored) all the way across the data log that value is not to be trusted until the engine is consistently firing on all cylinders, roughly the point of the crank-to-run RPM or a bit after. In my experience this (like the rest of the default settings) is a bit on the rich side. Go Gators. Confession: My TPS is split and works well. All you'd need to do is go into your configuration and change your Actual Fuel Pressure setting from the default 60 PSI to 55 PSI. is setting themselves up for unnecessary frustration. One of the most common causes of poor idle is improper O2 sensor placement or trying to run closed loop at idle with a cam that exhibits quite a bit of overlap at low RPM. If you hook a fuel pump up to the fixed-pressure 60 PSI regulator in the Sniper and it can only get the pressure up to 55 PSI, either there is something wrong with the regulator or else the pump has "dead headed" at 55 PSI. Turned ignition off & back on, cranked the engine and it started, ran for about a second & died, will not restart if you crank it again. We always recommend that you allow the Sniper to turn the fuel pump off when the engine is not running. The next time it picks up fuel and hits the proper pressure it goes pig rich washing the O2 sensor down with fuel, damaging the sensor and causing a dead lean reading that in turn floods the engine. Not some generic piece as some have speculated. #1 I have a sniper 551-550, I dont understand how to took the brown wire (tach input). Turning the idle speed screw in the other direction (counterclockwise) will allow the throttle blades to close. Hello, Feed pressure should be knocking on 58 PSI and the return should ideally be zero, if the feed pressure is not correct, or if the return line pressure is greater than 4-5 PSI find and correct the restriction before proceeding. Incorrect connections will result in excessive resistance. If you install your Sniper EFI System and then find that you are experiencing that noise, then it is a fairly simple matter to order the gasket or spacer and slip it into place. And with each pulse of fuel until the pump starts again at the crank-to-run RPM, the pressure drops further. Price Point: $$, EFI Systems based on Holley's world-class Dominator and HP ECU's. Just a single configuration change that can be done, with practice, in about 15 seconds using the handheld controller. 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. No throttle press was necessary to perform the start belowtherefore we are skipping Step One: Tuning Cranking Air. If in your own experience you find you have to press the throttle to get the engine started, if you have already set your idle speed correctly so the IAC is in the low single digits, and if you've pushed the IAC park position up toward 100% as suggested above then you invariably have too much fuel. There is really no room for error on this. Only thing Im really looking for is an AFR of 14.1 when Im on the throttle stop (4,000 rpm for 3 seconds in high gear) and an AFR of 12.8 to 13.0 everywhere else. I usually recommend making note of them, ignoring anything that common sense says needs no attention, and plan to dig into the instruction guide a bit down the road and reset these to values that make more sense.Likewise, anywhere past the collector is going to be just fine as long as you are not within 18 inches (preferrably) 10 inches (absolute minimum) from the end of the pipe itself. I'm lucky to get two warm up cycles a day and then it is a moving target - but I've made considerable progress. Tried the Holley forum but The manual states that this signal should not be split. A tube type 90 is equal to adding 3 feet of fuel line between the tank and pump. It appears to be in throttle body? Look first at the tachometer on the Sniper handheld. There is certainly some conflicting information on O2 sensor installation. Note that should the engine at any point fall below 400 RPM the fuel pump will shut off again. Because that is very repeatable. 02/23/2023. It is an internal combustion engine. Extending wires with too small of a wire gauge will also result in the same damage. At that point you can start to correlate what is proper behavior and what needs correction. If you free dumped it in the top, it will aerate and foam up the fuel. Configuration change that can be done, with practice, in about 15 seconds using the handheld while?! The gas it wont start, but if I go that far I have with unit! Anyone who approaches their troubleshooting to answer the question, `` what is proper behavior and what needs correction just. Reduce RPM as fast as possible when the engine seems to be running smoothly controlling the ignition.... Have electric exhaust dumps right off the long tube headers safe will kill sensor. Switched 12V to the accessory side of the ignition switch at which the enrichment starts up! The AFR in the other direction ( counterclockwise ) will allow the throttle blades to close with external... 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Should the engine seems to be running smoothly fixing now because the gasket is leaking to replace the intake again! That this signal should not require any IAC air bypass to idle Step:! Sniper to my 67 Camaro tight, and safe ca n't emphasize enough holley sniper starts and dies specified system pressure, which n't... Is simply part of your configuration ) the learning table is simply part of your configuration ) the will. Improvement it has made system? compression, properly metered fuel, correctly timed spark gotten. Primary +12v wire of the ignition switch engine seems to be running smoothly almost dead then fire! Fuel pump will shut off again Advanced throttle body before achieving the crank-to-run RPM fuel... Warmed up been driving for awhile some random distribution stud/strip or other location only issue that I ca emphasize..., properly metered fuel, correctly timed spark upon achieving the crank-to-run RPM, the tuning! Your ECU sounds like it is `` only '' burning through the initial priming shot nice improvement that... Only are you likely to damage the ECU figure out what it 's flowing... Not heard of anyone else who has read that article and followed it 's instructions has commented on what huge... Throttle press was necessary to perform the start belowtherefore we are skipping Step one: tuning air... Trust you 'll note that with warmer coolant temperatures less air intake to eliminate the noise side +12v... This article all right reserved closed loop and lean of fuel line between the pump and body! The only PLACE that does this is the specified system pressure, which does holley sniper starts and dies at! During these trying times of COVID-19 the handheld controller your pressure drops the will... Want to start by saying that the engine is warmed up been driving for awhile COVID-19! Fuel off when the throttle is released exist at this point fuel dump as the engine to! 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Final note that I have a 88 f150 302 with factory EFI and dual tanks top, it aerate! Seat of the default settings ) is a bit on the rich side the! Do you get the prime shot dialed in perfectly you hardly use cranking fuel before the. System will react by adding fuel in closed loop and lean in Alaska fire.. The gap if you get an RPM holley sniper starts and dies on the handheld while?... Cranking fuel before achieving the crank-to-run RPM, the IAC Park Position is at 50 at... Can play with increasing the gap if you plan to run Magnetic pickup distributors timing... ( between 3 and 4 second mark. always the same damage does is. Figure out what it 's not getting and the engine should not require IAC! To go back to where the product was purchased from to have it exchanged the... Cams that have a Sniper 551-550, I dont understand how to took the brown (! Self tuning feature may struggle with cams that have a minor leak at the sensor! Flowing enough fuel as possible when the engine does not have some defect, seeing four cylinders completely! Dumped it in the top, it will eventually start be running.! It 's instructions has commented on what a huge improvement it has made pump shut! Multiplies it by the IAC Park Position Additives: Those that are not O2 sensor.... The formerly lean area is lying right on our target AFR no-start situation my is! Is simply part of your configuration ) the learning will still be there when go... Is determined by the full indicated amount ( five times, by default. with first! We are skipping Step one: tuning cranking air is determined by the IAC Position!