Good point. Set the X Axis to RPM5. This helps ensure that any trash that might have been in the line somewhere is swept somewhere other than into an injector. (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. Otherwise, two sensors could theoretically provide some benefit but only if something were going wrong on the engine. Lets try 75% on the fuel prime. If neither of these are the case then you'll need to go back to where you bought the system and ask them about returning the pump. After adjusting the manual setting on the unit, the TPS was @ 3 and his Idle was pretty high @ about 1500 rpm. 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. I am running a wet exhaust with O2 sensor plates. Anyone who approaches their troubleshooting to answer the question, "What is wrong with my EFI system?" The problem isn't the 55 PSI. Mine did the same thing, and all I had to do was adjust the idle speed screw a little. 03-14-2018, 07:03 PM. Correctly tuned, your EFI-equipped car should start within a few cylinder firings with no application of the throttle. Well, my friend, that is where good automotive troubleshooting techniques come into play. Another great dissertation. Please continue to write these type articles as they are invaluable to your customers. This is a CRITICAL safety control and the reason why one should never consider powering their fuel pump with any power source that is not controlled by the ECU. But weve also introduced some leanness from 4-10 seconds. Incorrect connections will result in excessive resistance. If the switch has an engineered dead spot between run and crank ( It did not matter with a carburetor when they designed your vehicle, but its not EFI friendly) and its just not plum worn out, you can install a time delay relay in-line to correct this I use relay part number 74985 from Delcity to overcome the switch design. Now were getting there. 02/23/2023. Pin 87: To Sniper 12-Volt Switched (Pink Wire)When the ignition key is switched to "on" then power will flow between pins 86 and 85, closing the switch between pins 30 and 87. Like its legendary 4150 carburetors, Holley's Sniper EFI is a clear choice for so many builds that there's no way for it not to take our top . This value can be changed using either the handheld or the software but I am not familiar with a case where changing the crank-to-run RPM has been beneficial. Being a throttle-body based injection system, it gets an adequate picture of the air/fuel mixture by seeing a blend of all of the exhaust ports on one side of the engine. Until then, Terminator X users will have to work with the cranking fuel table alone to create a temperature-dependent fuel shot. It does take some time looking at these data logs before they look like something more than the scribblings of a 2-year-old. But with patience you will get there. The IAC Park Position is a temperature-dependent value that can be adjusted in the following ways: Using the handheld Tuning > Advanced > Adv. Any help with this would be greatly appreciated.Gary. Activate "Switched Enable" and select an available input to act as the activation.You then go into the table and make all of the RPM settings match those in the Target AFR table. Just realize that you risk aerating the fuel a bit depending on how it enters the tank. Connect the crank and run wires together and all should be good. But you can extend the leads using wires of an equal or heavier gauge. If I let it prime twice, it starts much faster. You mentioned its use in # 9 of the top 10 Sniper EFI installation tips. I just finished installing a Sniper stealth 4150 with an external pump supplied with the kit. IAC Hold: How far open the IAC is when the throttle position is 2% or greater. You also need to properly phase the rotor. Thanks. 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 . Does the pink turn-on wire have 12V while the ignition is in the crank & run position? Proper plug readings would need to be done to confirm if you can go any leaner WOT tuning. My articles are an attempt to provide an introduction to the familiarity. EMI is what wipes out all the electronics. ), Do you see a single brief pulse of fuel injected, in equal amount, in all barrels? To do rev limiter operations requires that the Sniper be controlling the ignition timing. Yes, ensure the Sniper EFI switched +12V pink wire is powered in the "Run". Any suggestions ? is setting themselves up for unnecessary frustration. Is the fuel pressure correct? 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.) 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. MSD recommends non resistor plugs. First, remember that after-Start enrichment is not a fixed value. Use whatever target AFR the system is initially suggesting and try to get your actual AFR's within about 1 to 1.5 of that value. 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. I took that phrase directly from Holley's tuning manual and I specifically recall my left brain asking my right brain, "Hey, that doesn't seem right" and my right brain responding, "Shut up! I could really go on a long time about this but it sort of deviates from the basic goal of this article. Engines require three things to run. Assuming you have no vacuum leaks or a lean idle AFR, your idle speed is too high for your stall speed or your stall speed is too low for your engine combination. I never changed any wiring just removed the sniper and installed the xflow. Car ran great prior to SNIPER install with 750 holley single pump single feed SAME radiator but since have upgraded to dual 11 fans 4400 cfm up from twin 10 at 3500 cfm. Too much and it will simply idle high and can be manually adjusted down. While it is true that, ultimately, all of the 12-volt switched power sources are connected at some point, distance is your friend. And 10 micron filter between the pump and throttle body. First is the fact that the engine can be getting either too much or too little fuel. Use a touch of dielectric grease on the leading edge of the boot and ensure that each one is firmly locked into place with air squeezed out of the boot as much as possible. I also have dual sync distributor and same accel super stock 8140 coil to run as soon as i work all bugs out of FI conversion. As Tom says above, it is best if the fuel is returned to the tank below the fuel line if possible. Does the sniper kit support dual O2 sensors? Can I lower it for this purpose? 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. The sole purpose of this is to prevent stalling, so change one thing at a time and if you find your engine stalling then back up a bit.The four key settings:1.) Thanks. Is there enough cable to get to the battery? That delay is called After-Start Holdoff. Yes, I have fuel pressure. If your pressure drops the system will react by adding fuel in closed loop and lean. Should the fuel pressure hold steady while the engine is operating as when the key is on but not starting or should the pressure readings be oscillating rapidly in a frequency that seems to match the clicking noise emitting from the tbi. If it cranks better then you know you're getting too much fuel. No aftermarket EFI system should be without a way of confirming fuel pressure. We stock the PTFE hose and can source as many pieces as are required to reach the bottom of the tank. PIck a size that will not just lay flat inside your fuel cell but will actually run up the sides and back. Keep ignition wires away from ECU harnesses and use dielectric grease on your boots to aid in RF suppression. I suspect this is the case in a huge number of "problematic" EFI installations where the system is getting the blame. I seen it said to wire the blue wire not to the 12v accessory which I do understand. There should be 1 AWG or larger ground strap going direct from the battery to the engine. So now youre left with tuning the Fuel Prime Multiplier. That helped. If you turn the ignition off and back on, & crank it, it will start & die again. Unless there are some sort of idiosyncrasies specific to the fuel system on the '88 Ford F150 of which I am unaware, this should work fine provided the factory pumps can provide enough fuel for the current engine. In my experience this (like the rest of the default settings) is a bit on the rich side. Now that were up and running lets go deeper and see what can be done to improve things. EFI sniper installed and dialed in perfectly as per directions, starts, stops, idles at 750-ish drives great. If the fuel pressure is a little low don't worry about that. First, it is fake news that EFI doesn't like big cams. No, it did not help. It needs to have a 80-100 micron pre-filter installed between the tank and the pump. If it is more than about 5 PSI one way or the other, or if it changes under different operating conditions, then you should look into that. Does pressing the throttle slightly allow the engine to start. I am having a 2 572 BBC being built for my boat. injection systems capable of There should be no relay added to this wire. As long as your fuel pressure is within a few PSI +/- of 58 and consistent then everything is fine. Sometimes just moving a fitting or changing the length of a line is enough to confound the harmonic and make it go away. Ive gotten my hot starts really dialed in, but I always get a longer crank than I like on the first cold start (usually 60-70 degrees ambient). May God's grace bless you in the Lord Jesus Christ. Would I need to go back to where the product was purchased from to have it exchanged via the warranty conditions? We offer two potential solutions. You see that the AFR trace is ar below the target AFR (pink trace.) But as you go farther back, it only gets better. Do I still need the holley 12-753 30 amp relay. 4.) This is obviously an ongoing process. classic car or truck 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. Find a lower price anywhere and we'll beat it by 5%! Icle > IAC Startup > IAC Park Position, Using the software Idle ICF (tachometer icon) > IAC Parked Selection. You are on the right track!Let me start by saying that I normally don't advise anyone to make changes to this until they have the system tuned as good as it can get and unless they have a bit of tuning experience. 12/02/2009. Now, at each RPM setting you'd add (or subtract) whatever from the Target AFR so that the new target is 14.0:1. Bolt-on carburetor style EFI for your classic car or truck. i.e., 5x at -40 and 0 at 160. Advanced throttle body injection systems capable of transmission control and more. 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! Run the switched 12-volt back as close to the ignition as possible. Hello Chris. Oxygen sensors read unburnt Oxygen not Fuel. At first start-up, you prefer that the throttle blades be open enough to supply adequate air for the engine to crank. Cold cranking cant be tuned the same way because the engine will get progressively warmer as the engine is cranked, Prime shot can be enabled or disabled entirely and is calculated using two values: The Fuel Prime Percentage (Sniper and Terminator X), and the Fuel Prime Multiplier (Sniper only.) A coolant temperature enrichment factor will be applied if the engine is not up to operating temperature but a bit more fuel is normally beneficial as well. There is a correct setting for the idle and it sound should not be a consideration. By doing this you ensure that the Sniper can cut fuel off when the engine is not running. I'm lucky to get two warm up cycles a day and then it is a moving target - but I've made considerable progress. I did find a couple and it did get a little better but still not satisfied with it.What is the ISC hold position for and why is it set @ 30? The images are NOT intended to provide you with the values you should be using in your configuration. Cheers Darren. The bottom line is that the more of the complete exhaust stream the O2 sensor can see, the better. 2023 HOLLEY PERFORMANCE PRODUCTS, INC. ALL RIGHTS RESERVED. So I can't tell you what TPS to use. I'm considering the super sniper for my C3 corvette(modified sbc) , which will eventually have a pro charger. Footage taken from Holley Carburetor Installation & Tuning DVD Winter Blowout Sale - Up To 86% Off . You accidentally wired the switched 12V to the accessory side of the ignition switch. Fyi both fuel pump rocker switches have momentary primes. Do you see a very thin amount of fuel being injected evenly on all throttle plates? The amount of air allowed in is configured via the IAC Park Position and is temperature dependent. My car is going on the dyno for final tuning next week. If you . 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. I'm worried that the engine will stall at idle. EFI doesn't have feelings--it doesn't care what cam you use. The kit I bought: https://www.summitracing.com/parts/sne-550-511 Also for timing control, this distributor: https://www.summitracing.com/parts/sne-565-302 Awesome Article. All times are GMT-6. 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 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. Then I will provide an image of how this variable looks in the software. If so is there a way to connect to a standby auxiliary 12 volt battery to the Sniper to protect the information?Many thanks,Louis. Just a single configuration change that can be done, with practice, in about 15 seconds using the handheld controller. You should then have at least 18-24 of pipe after the sensor. Directly to the BATTERY!!! Will going further help more? Im not looking for timing control just upgrade to EFI. This is most often a result of air flowing through the IAC port related to the IAC hold Position and is normal. However, each engine is different. Your thoughts?In your opinion, should I keep the factory cast iron intake or should I replace it with a more efficient one. Then is the actual amount of enrichment, which is set in the After-Start Enrichment table. So try cutting both of those numbers in half and see what happens. As a minimum I would ensure that the system has had adequate time learning in the high-load areas of the map where you will be operating before trying this. If you turn the ignition off and back on, & crank it, it will start & die again. Price Point: $$$. Holley Sniper EFI Check Latest Price. Https: //www.summitracing.com/parts/sne-565-302 Awesome article purchased from to have a 80-100 micron pre-filter installed between tank! 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