*Possible delays due to Covid-19 click for more information. Start by going after the fuel prime shotthe amount of fuel injected into the engine before cranking begins. Why? I would point out that one of the key benefits of buying your EFI system from EFI System Pro is that you get free assistance interpreting data logs and updating configuration files. Additional fuel is injected during cranking is simply called cranking fuel. transmission control and more. Is the fuel pressure correct? I have been looking at all efi units and I keep coming back to the Sniper. If you don't show any fuel pressure then fix that. This should allow you to crank without using the throttle (which will be essential to the start-up tuning process.). Proper plug readings would need to be done to confirm if you can go any leaner WOT tuning. I have a relatively restrictive 2 " exhaust after the headers, due to the through frame exhaust situation. Can I run the pink ignition wire to the coil positive? It's almost impossible to hurt an engine with no load on it. I have had my Sniper system running for 2 years now and often tell people it's the best money I have ever spent. A common issue we see is a result of poor fuel pump grounding running a eyelet from the pump ground to a rusty or painted surface. Can you post a photo of the wiring on the ignition switch? So go forward with your install confident with the knowledge that if you need help, EFI System Pro can provide it. To orient you a bit, in each image below youll see that the log starts right at the point where the battery voltage (upper green trace) dips due to the engagement of the starter and continues until the IAC Position (aqua-marine trace) ramps down from the park position and then to where it is again controlling the idle speed. Directly to the BATTERY!!! I have a aeromotive stealth 340 fuel tank. Get a gauge. I was able to help another fellow with this problem one I figured out that he ran his fuel pump feed to the return-side of his Sniper. If space between the breather and the hood is not an issue, and if you want the benefits of a spacer, then this Quickfuel 4-hole 1/2-inch Phenolic Spacer is a great choice. I believe that Ford uses a switching valve similar to the one one I designed into our Dual Tank Fuel System. 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. From there it is a slam dunk. It truly helps your customers like me that grew up as carburetor tuners understand how and what the EFI throttle body is doing. Why? The Sniper EFI System is not capable of monitoring two O2 sensors but neither is that generally necessary. 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. But as you go farther back, it only gets better. There must be an option that has been found to work. :-D. Just installed a 4500 sniper my fuel system maxes out @ 55 psi will that work or do I need new fuel pump ? The Ordering process was so easy and non-painful. . That helped. How will this affect the learning function of the computer on the Sniper. Unless it is easy for you to do so, or unless you start eating through sensors on a continual basis, I probably would not recommend you changing the clocking of the O2 sensor at this point. 12/02/2009. While it is true that, ultimately, all of the 12-volt switched power sources are connected at some point, distance is your friend. If I go to ignition switch it is the same wire just 2 away. Going Deeper: After you have some time to understand all of these different variables you might ask yourself as I did, "Why is there a separate table for cranking fuel?" Holley Sniper First Start. It will come back up when the engine is running.If you have fuel pressure then you've got to dig deeper. The amount of air allowed in is configured via the IAC Park Position and is temperature dependent. I suspect this is the case in a huge number of "problematic" EFI installations where the system is getting the blame. This is normally completely adequate. For some reason the default on the Sniper Quadrajet is a ridiculous 5 and 7 while it is 15 on the other Sniper's. That delay is called After-Start Holdoff. Price Point: $$, Robust, feature-rich I've read that you can data log, my question is are there any professionals that can analyze the log and actually help write one for you that will help with the fine tuning. Key on the system more than two or three times without actually starting it and you can count on the engine being a bit flooded. 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. 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. In fact, they may be terrible values when applied to your engine. I call this the Happy Dance moment. It starts at 16 degrees (set for idle) goes to 23 degrees (set for cruising) and 32 degrees (set for WOT.) It is going on a 1966 coronet with 1964 413 wedge. Can I get ready made tunes?Even with this problem it is by far the best fuel system I have owned. Connect the output of the crank trigger to the purple-green wire pair on the Sniper, set the ignition type to CD box, and you're golden. It drains the battery almost dead then will fire up. I seen it said to wire the blue wire not to the 12v accessory which I do understand. So here's how I'd do it:Pin 86: To your ignition switch (12 volts) I did put an external regulator on fuel return but other than that everything is the same. Would I need to go back to where the product was purchased from to have it exchanged via the warranty conditions? Nice catch, Ken! Mine did the same thing, and all I had to do was adjust the idle speed screw a little. Hard starting cool but starts easy when hot. you will observe that they are almost IDENTICAL when it comes to AFR. 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. Thank you for your ongoing support. My question is if both of my fuel pumps are wired from relays to my rocker panel where does the blue fuel pump prime wire connect or would you just not use it altogether. Starts & immediately dies. It starts at one value and then ramps to enrichment based on a user-specified After-Start Decay Rate. 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. Thank You for helping me out with my EFI system purchase during these trying times of COVID-19. Figure out what it's not getting and the find out why. I really would like to replace the intake gaskets. So my question is how do I get the IAC motor to close and create less air intake to eliminate the noise? 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. 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 you . 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. Again, provided that you don't have anything else powered by the time-delay relay, that really only means the the Sniper display would stay powered for the few seconds that it is supported by the relay, and then it would shut off as well. Holley knows how to do math! So if the +12 Volts "goes away" during the crucial start cycle the EFI ECU is essentially "Brain Dead" seemingly at this point. ), Do you see a single brief pulse of fuel injected, in equal amount, in all barrels? Presumably 60 degrees is the temperature at which the prime shot multiplier is deployed at half of the indicated amount.). But I have MSD 6 AL. Runs good, but dies while I drive down the road. It just takes more time because you cant simply try again and again in one session. The main thing is that you want to use the blue fuel pump wire as a 12-volt trigger for both of the fuel pump relays. Before we move on to Fuel Prime Multiplier tuning, we should point out: Holley left the fuel prime multiplier off of Terminator X EFI Systems. 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. It seems to be going threw gas faster then it should. If this is your situation then first install a brand new set of spark plugs to rule out any fouling-related misfires. Most important!!! 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. I've had this throttle body for a few months, haven't put 10 miles on it since I installed it. Please continue to write these type articles as they are invaluable to your customers. 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. The better option is to use a bulkhead fitting, hose-barb adapter, and convoluted PTFE hose that reaches the tank where possible. Thanks. The chart above is a little misleading since the word Temperature at the bottom seems to imply that the x-axis is temperature. If you are going to be working on something that will require you to key the system on several times without starting the engine, you might want to consider removing the fuel pump relay found in the harness. So now youre left with tuning the Fuel Prime Multiplier. Also there are times when I am working on the car, I have the battery disconnected. That added fuel is called after-start enrichment. 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. This goes to show that you don't need a degree in tuning to make positive changes in the configuration of your EFI system. Latest Articles. Most current pump fuels boil around 130 degrees. Set the X Axis to RPM5. Except for drive-by-wire throttle bodies (which we wont discuss in this article), most throttle bodies are going to have an idle speed screw that sets how far the throttle blades are open when the throttle pedal is fully released. You should then have at least 18-24 of pipe after the sensor. 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? Seems like thats what its doing. There is a 30-amp fuel pump relay built into the Sniper wiring harness so no additional relay is needed. 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.) 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. 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). Great article. But you don't mention fuel pressure at the inlet. 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. 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