It turns out that in EFI , as in life, there are no shortcuts to excellence. 2.) . Not some generic pump as some have speculated. Do you have issues with cold start that go away with warm start, or vice versa? I have a few questions: I was planning on installing a Edlebrock dual plane intake and I now hear that the Sniper does not work too well with dual plane. 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. i have installed a sniper 2300 on my 1971 225 oddfire v6 with a crank trigger for rpm signal. Even better, buy yourself a bit of insurance by scheduling some dyno tuning (fuel and ignition timing) with a competent professional tuner. Good luck! Would love some feedback as what I need to do to help my issue. Out of the box, Holley normally has their idle speed screw set at 2 to 2 full turns beyond the point where the screw first hits the throttle lever. But never ever forget there is a second learning going on--your own. In virtually all cases, this will be more than the amount of air it needs to idle. 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. Then, reduce your after-start enrichment by about 10% in the temperature range where youre tuning. Further frustrating the effort is the fact that the air/fuel ratios provided before the engine is firing on all cylinders are essentially meaningless. I have purchased two sniper EFI with the MSD distributor kit. Exactly. The majority of the idle air is going to come past the throttle plates, held slightly open by the idle air screw. Capability Range: Moderate Great article. How will this setup work? Ran well on carb and electronic ignition. The engine starts and idles great. But few have a crimper that is capable of executing a truly excellent crimp. Extending wires with too small of a wire gauge will also result in the same damage. This is normally completely adequate. Capability Range: Advanced Turning the idle speed screw in the other direction (counterclockwise) will allow the throttle blades to close. We offer two potential solutions. I still have the lound sucking air sound. 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.) How efficient is your engine startup? No aftermarket EFI system should be without a way of confirming fuel pressure. to zero, but I think you'll find that you will stall. 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. In a you tube video I watched , the presentaor indicated that the return fuel line could be routed to the filler neck ( of the tank ). All of the hard starting issues were IMMEDIATELY RESOLVED both cold starting AND hot starting issues, the car still runs like a scalded dog, and the screen no longer drops out when cranking the car.IN THEORY - The throttle body and ECU is looking to control cranking fuel, starting fuel, after start fuel enrichment, and IAC positions AT START. you will observe that they are almost IDENTICAL when it comes to AFR. Pressure holds steady at approximately 50 psig when engine is off. Then I will provide an image of how this variable looks in the software. 3.) Some good info here thank you. Don't let that get the best of you. The clocking of the O2 sensor is not a go / no-go situation as far as the operation of the EFI system. By going with an aftermarket manifold you avoid that issue entirely.Just as a side note, when you convert over to the Sniper EFI System, here is a great, direct-fit fuel pump option that will provide both the flow and pressure you need for your '87 Firebird (as well as almost any GM TBI engine of that period. We do see a massive rich dip in the AFR as soon as engine starts. 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. Most current pump fuels boil around 130 degrees. Free ground shipping regardless of order size! :-D. Just installed a 4500 sniper my fuel system maxes out @ 55 psi will that work or do I need new fuel pump ? The IAC is essentially a computer controlled vacuum leak that allows additional air past the throttle plates to assist in idle stability and additional cold idle speed. This is most often a result of air flowing through the IAC port related to the IAC hold Position and is normal. But I'm confident that once you wire it this way you will not have the problem anymore. If it is too large then the engine will rev higher than necessary, which can be a little annoying but is not harmful to anything other than your nerves. 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. 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. It builds fuel pressure in the fuel line and then turns the pump off until the engine starts running. I am now awaiting my new Sniper Stealth 4150 to install on my 1968 Corvette 427. Lets note for the record that the time from power on starter solenoid to achieve crank-to-run RPM is 1.13 seconds. When the system is initially powered on, the fuel pump comes on for a few seconds to pressurize the fuel lines. If it dies add fuel right away thru the carb opening a few drops at a time if it runs its the fuel pump. Third is the truth that every engine has its own preference on what it likes for startup fuel. what is the proper air/fuel ratio for a sniper on a ford fe 352? That clicking sound you may be hearing is most likely the fuel injectors cycling, this sound is often more pronounced at Low RPM. 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. Most important!!! multi-port EFI systems Provided that your ignition is not also being powered by the time delay relay, the engine would shut off as soon as you switch off power, at which point the Sniper would immediately switch off the fuel pump.The Sniper EFI System, however, would not shut off until the delay timed out. Just recently installed the Xflow and my AFR is reading is 15 no matter what I do, engine is running ridiculously rich but the AFR is not changing at all is this an ECU problem or is there some things I can try doing before I pull it off and send it back to holley? Question is, do I just plug what was the return at the throttle body? 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. I've never seen the shop I had install my Sniper hook up a lap top to the car. As Tom says above, it is best if the fuel is returned to the tank below the fuel line if possible. Nothing else (except gas), In a no-start situation my direction is always the same. Not some generic piece as some have speculated. The only issue that I have with this unit is the loud suction sound coming from the IAC port. Unfortunately, the tuning ease of a Holley also creates some tuning problems. Let me know what works for you! As I suggest above lets start with the fuel prime percent, taking it from 150% to 100% and see what that does. This is a bit tricky. 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. Figure out what it's not getting and the find out why. If I tap the gas it wont start, but if I hold throttle wide open it will eventually start. I'm considering the super sniper for my C3 corvette(modified sbc) , which will eventually have a pro charger. If you get in a situation where you believe the engine is flooded, remember that there is a Clear Flood TPS value, normally defaulted to 60%. The engine warms up a bit each time. Is a tremendous volume of fuel sprayed in all barrels? If it cranks better then you know you're getting too much fuel. This happens with some carburetors on dual planes as well. PIck a size that will not just lay flat inside your fuel cell but will actually run up the sides and back. 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. So I can't tell you what TPS to use. it runs well at part throttle but at wide open throttle the engine has very little power and backfires.where do i go from here. Once you've done that then you can see if you don't benefit from going a bit higher or lower. He then cycled the key off then back on again and TPS was back to 0 and the idle was back down to around 800rpm. We always recommend that you allow the Sniper to turn the fuel pump off when the engine is not running. But I can tell you that it is possible to use a switched input to activate a 1-Dimensional Advanced Table to do an air-fuel ratio offset that would allow you to set your target AFR to 14:1. I plan on converting to efi this coming spring. Holley EFI for Beginners // Where to Start // Sniper, Terminator X, HP/ DominatorHolley Efi Tutorials: https://youtube.com/playlist?list=PLN6EQoVPwAwHzmhEknk. Most import. Is the spark occurring at roughly the advance we expect it to be to promote ignition? I have a aeromotive stealth 340 fuel tank. I would also point out that these settings are easier to adjust using the Sniper Software than the handheld, though either will work.There are several settings that affect how quickly the idle returns to target. Sure enough the pink wire DID NOT have voltage when cranking. We can adjust that with the after-Start enrichmentIll bump that up a bit. But as long as you keep a copy of your original configuration settings I think you will be okay. My fuel pump keeps running when the ignition is on but the motor is not. 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. As the vacuum required to overcome a restriction or lift required to get fuel to a high mounted pump and the resulting reduction in pressure can and will boil fuel in the line and at the pump inlet resulting in fuel pressure issues and pump damage. I have had my Sniper system running for 2 years now and often tell people it's the best money I have ever spent. Be sure to properly gap your plugs and if you plan to run Magnetic pickup distributors for timing control. I know it's only 2 feet but ever inch counts. "Wouldn't the prime shot be half (2.5x) at 60 degrees and not 40 degrees? I'm trying to get this article done. Nor can I really recommend that you split it as I have. Too much fuel a result of air flowing through the IAC port related to the tank below the fuel and... Sbc ), which will eventually have a crimper that is capable of executing a truly excellent crimp pick size. Or lower feet but ever inch counts but will actually run up the sides back... Line and then turns the pump off until the engine has very little and. Frustrating the effort is the loud suction sound coming from the IAC port to. My issue, HP/ DominatorHolley EFI Tutorials: https: //youtube.com/playlist? list=PLN6EQoVPwAwHzmhEknk and! 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