https://www.msdperformance.com/suppos/#EngineRunOn, If this is your first visit, be sure to Top 10 Sniper EFI Installation Tips from Holley's Tom Kise, Quickfuel 4-hole 1/2-inch Phenolic Spacer. The default for these systems is 400 RPM. I prefer solder and heat-shrink but technically speaking a well-executed crimp-connection is actually superior. He took a flash light and looked down at the IAC motor position and it had moved quite a bit closing off the port.Now I had to try this and of course my results were not so lucky. That delay is called After-Start Holdoff. :-). Disable the tach sweep on your ignition box. Maybe I am missing something here. We offer several different levels of fee-based support that is very reasonably priced. I just installed a Sniper 4150 on my 78 Monte Carlo with a stock 305 and a dual plane intake. I created logs in the past but never knew what I should be seeing and how to make the specific tweaks. (Only visible with throttle bodies that have the annular rings on top of the throttle plates.). And that from a not-so-shabby original 1.13-second start time. Failing to do so could result in a very dangerous situation if the fuel pump kept running when a fuel line were cut in an accident. The ignition will ingest the prime shot, fire off a couple of cylinders, and the engine will start before the cranking fuel really makes it into the cylinders. *Possible delays due to Covid-19 click for more information. If your pressure drops the system will react by adding fuel in closed loop and lean. features . May 23, 2022. Fix that.If you have RPM then look at the pressure gauge and see if you have fuel pressure. It's almost impossible to hurt an engine with no load on it. The amount of air coming through this port is determined by the Idle Air Controller (IAC.) (Ive written another article that includes one technique forsetting your idle speed correctly.) Because all it knows is the specified system pressure, which doesn't exist at this point. Find a lower price anywhere and we'll beat it by 5%! This, in turn, will power the Sniper. However, the majority of these are set from the factory at values that simply don't require any attention at all. You see that the AFR trace is ar below the target AFR (pink trace.) (Plus, it's easy to do---see this article.) Price Point: $, Advanced throttle body injection systems capable of transmission control and more. I think my tach is on there. Thanks for your help system is working great!My question now is where can I find more info on fine-tuning, especially timing. What I've read indicates this comes from the fuel pressure regulator and is often associated with systems that happen to have 90-degree fittings (though not always.) Thats what we want, right? Even if you don't let the engine get warm you will have changed the starting characteristics by making a start so you'll need to wait for the engine to get back to a fully cold/dry state before you can data log another start and measure the effectiveness of it.But you already have a pretty good clue that you need more fuel if two prime shots make it easier to start. Go to the Fuel ICF, Acceleration Enrichment, and then click on AE vs TPS Rate of Change. Can you post a photo of the wiring on the ignition switch? What this tells us: First, we dont have any huge problems. Designing a fuel system that can pick up fuel at all fill levels and with a nearly 90-degree angle on the tank is a challenge. 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. At -40 degrees it multiplies it by the full indicated amount (five times, by default.) Sniper is working pretty well after using your idle setting procedures. Lets dig down into that a bit and see if we can help. 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. Your advice would be appreciated. 2-Barrel Sniper EFI 2300 Sniper EFI C10. My first rule: There has never been an engine that didnt start because EFI. 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. Push the fuel prime percentage back up to 100% and bring your cranking fuel down (as we do in the example below.). In the example below, the IAC Park Position is at 50 percent at normal operating temperatures. Find a lower price anywhere and we'll beat it by 5%! While it is true that, ultimately, all of the 12-volt switched power sources are connected at some point, distance is your friend. Quick Start Tuning. If you turn the ignition off and back on, & crank it, it will start & die again. Second is the fact that there are three things that you are adjusting here: Prime shot, cranking fuel, and after-Start enrichment. FSM Manuals Jeep Manuals. For some reason the default on the Sniper Quadrajet is a ridiculous 5 and 7 while it is 15 on the other Sniper's. This will cavitate and damage the pump as well as result in drivability issues. Just a single configuration change that can be done, with practice, in about 15 seconds using the handheld controller. Does this mean it will have to learn all over again? 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. RPM Above Idle to Start Ramp: When you lift from the throttle the ECU won't try to control the idle until it is within this many RPM of your target. Check your fuel pressure during installation at both the feed and return lines. I strongly recommend EFI System Pro. The Sniper ships with an OEM grade Bosch O2 sensor. In a nutshell, you do the following:1. I mean, after all, we already have a base fuel map that provides a baseline for the fuel required by the engine to operate at this RPM. This is a huge improvement over what we got initially. 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. Then is the actual amount of enrichment, which is set in the After-Start Enrichment table. The better option is to use a bulkhead fitting, hose-barb adapter, and convoluted PTFE hose that reaches the tank where possible. My car idles beautifully @ about 800rpm. I have just finished installing my Holley Sniper to my 67 Camaro. 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. Lets note for the record that the time from power on starter solenoid to achieve crank-to-run RPM is 1.13 seconds. Did your engine start the first time you turned the key after installing your EFI system? These are listed on the handheld in the same window as the IAC Parked position (as described above.) Trying a different mounting gasket configuration of lowering the divider can change the air flow and quiet this down if it occurs. Wrong Sealants or Fuel Additives: Those that are not O2 sensor safe will kill your sensor. Sure. Is a tremendous volume of fuel sprayed into just one barrel? It starts fairly well. While cranking are you getting a reasonable RPM signal while cranking (usually about 150 RPM)? Any suggestions ? But you can take the same steps to adjust the temperature-dependent variables in the cold ranges when the engine is cold. In fact, if you overlay these two data logs with the comparison feature (did you know there is a comparison feature built into the data log viewer?) Nice catch, Ken! 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. So I installed my O2 sensor vertically, straight up & down on top of exhaust pipe about 18" after collector. I would add a 12v-switched relay to power your Sniper. First is the fact that the engine can be getting either too much or too little fuel. Lets try 75% on the fuel prime. I am running a wet exhaust with O2 sensor plates. I figured it would be minimal. The engine needs a certain amount of air during cranking in order to be able to start. I have been looking at all efi units and I keep coming back to the Sniper. All times are GMT-6. You will begin to notice when the system is in closed or open loop, what the target and actual AFR are, and when it is running right or running rich. But I strongly suspect that is not the case. I have an '89 Jeep 4.2L with a Sniper 2300 2BBL on it. Free ground shipping regardless of order size! If you do not disable it you will fight startup issues, flood the engine and damage your O2 sensor. This is most easily done using the blue fuel pump wire. :-), Can you show how do you wire up the Delcity time delay relay (#74985) for use with the efi ignition dead spot. A low air to fuel ratio means the mixture is rich. Connecting a grounding strap from battery to frame with a frame to engine may have been OK for your carburetor but its not sufficient for digital electronics. I am in the middle of plumbing my new sniper throttle body system. It is likely that the main power and ground leads are not long enough. Alternatively, the regulator can be removed and then what was a return can now be used as another feed. 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? Whether you tune via the handheld or software you are provided with a graph showing IAC parked position at the left and coolant temperature across the bottom. I was wondering if you could help out? And you don't pay a dime more for that--everything is the same price as every other Holley vendor but you get the service you deserve when making a purchase like this. It seems to be going threw gas faster then it should. Whats the fix? When one "assumes" it is EFI because they have an EFI system, well, I don't need to finish that sentence, do I? 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. 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. Many of these are completely normal with EFI. Thanks Chris, keep up the good work. Price Point: $$, Robust, feature-rich What we're primarily doing in this example is ensuring that we're tuning our start-up AFRs inside the range of common start-up AFRs. I kind of doubt there is anything truly scientific about 6-8 inches but rather a number that is probably safe for all headers. Let me know what works for you! Best Overall. How fast will the programing in the sniper be , in order to take advantage of a sudden open exhaust situation ? 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