Give them a call and if they are unable to provide customer support the contact the Holley tech support line at 1-866-464-6553. The answer will divide the possible sources of additional air into two, greatly simplifying the problem.If the IAC number has not increased, then review the article above regarding high idle from a vacuum leak or high idle from sticking linkage. Using the handheld, navigate to Tuning > Basic > Basic Idle and ensure your target idle speed is set to the RPM you desire. I haven't driven it for the 30-40 minutes like the several times it idled at 2200. If there is an issue with using the Sniper EFI TPS signal, is there a remote TPS or an adaptor for the Sniper EFI that allows the TPS signal to be accessed for the transmission. Tuning Your Sniper EFI System for Progressive Secondary Link Use Now that you've got your IAC set I'm going to recommend that you run your setup wizard again, which will reset the ECU to the default settings. It runs perfectly fine other wise. Top 10 Sniper EFI Installation Tips from Holley's Tom Kise I think that your timing is too retarded. It reads 0 at idle and when I accelerate it goes up to 30 and makes a loud sucking sound that seems to be holding the car back. Or alternator? I put sniper on in hopes to be able to just turn key and start without fumbling with pedal to keep it going and to correct idle drop when ac kicks on. It could be that the air flow across the secondaries as they are opening is creating that whistle but that isn't commonly the case.Did you check for leaks around the gasket of the air cleaner? All of the wiring exits below the rear fuel injector cover, for a completely stealth installation. What you are experiencing is rather common. I have verified that there are no vacuum leaks, not to mention the car runs to good to have a vacuum leak bad enough to make this noise. Tuning > Advanced > Adv Idle > IAC Startup Note too that the larger the throttle stab, the more brief the time in that cell and the more gradual the change.Here's what I recommend: Get somewhere where you can repeatedly stop and go. Keep in mind that at 60 miles the I' m going to put the 3 rd new pump this coming friday. We're having trouble with a Ford Maverick 302 V8, using ethanol. Holley Sniper EFI So try changing your IAC hold value slightly:Tuning : Advanced : Adv. And since they really had an insanely-tight monetary and real estate budget in the Sniper EFI System, it is unlikely that the added something that wasn't absolutely necessary--and then forgot to use it..And you are spot on about the little Earl's gauge with optional -6 AN port. If you drop it too far the engine will stumble or stall when coming off the throttle with the car out of gear, so you'll know when you've gone too far. Let me be perfectly clear: If your engine will not drop below 1350 RPM with the idle speed screw turned all the way out then you have an air leak. back upthe RPMs shoot up to anywhere between 1500 and 2000 and they will not get Shut off the engine, ensure power to the Sniper is switched off. When I covered the IAC with my finger, the RPM dropped so low it stalled. One of them might be faulty. I'm so glad you found this helpful--that makes my day!Don't get too concerned about the specific learn percentage. It drops about 200rpm when clutch engages. Ive tried setting the prime setting above 150 but it wont take, it always goes back to 150. The on board fuel pressure regulator in the Sniper throttle body has a small filter clipped over one end . It's pretty hard to get the header tubes glowing at idle with a lean AFR. So something is triggering the ECU to be in Open Loop. Otherwise, if removing the air cleaner eliminates the whistle then try to use a thicker gasket or try lightly greasing the gasket. Featured Products Sniper EFI $7.07 - $2,457.95 470 Products View Parts author Staff Writer 1711 Posts An Article About Video tech Sniper EFI Videos Sniper EFI Tech Sniper EFI sniper Installation check, I guess after reading everyone saying how great the system is after Thanks again. At that point the tps is pretty high, then shut the ignition off, pull the tape restart the engine and idle goes into hold mode and idle is through the roof. The "Gauge Text" is what would be shown on a 2-1/16 gauge or the Avenger handheld display. There is no sense proceeding until your TPS is at zero at key-on. Bolt-on carburetor style EFI for your classic car or truck. Last night I tried setting the IAC and had the same problems after it's warmed up. We're never going to fill up your email box with nonsense. One way is to very carefully watch the handheld monitor, and that may be adequate. That 60% (which is configurable) is known as the Clear Flood TPS. And, while that is happening, make a note of the temperature before you engage the starter, and then the rpm when it starts.The Idle Parked Position is set on a temperature-based graph like the Idle Speed Curve. We are using Target AFR of 9.0: 1, Fuel Base approximately 40% higher. It's all part of the adventure! If the engine will after the 4 seconds that the IAC kick drops off then it's not really going to help.At any rate, it costs you nothing to advance the ignition and see if that doesn't improve the idle, right? Thanks, That is an strange situation. Seems like its too slow to grab idle when ac kicks on. shut truck off. From herethe cycle continues and I am It's not necessary to drive it that way. I have checked the pink wire and it is at .001 volts when key is off. My IAC was constantly at 100% at idle. While you have over 200 miles on the system, you must realize that in the part of the map where the ECU finds itself during lanches you might only have a total of 5-10 seconds in any given cell. I think that a great number of the challenges that Sniper EFI System Owners face are brought on themselves by getting into the control settings before the system has really had a chance to learn. While confirming, in the handheld ensure that the Reference Angle is set to 57.5 and that the Inductive Delay is set to 100. I have a feeling it's something simple but I thought I'd ask you first before I inadvertently change something that affects other areas. Another suggestion is to add an extra turn to the spring built into the linkage to increase the closing force on the throttle shaft. Idle IAC problems? - Holley Performance Products Forums I would start by datalogging the situation and seeing exactly what your learn table looks like in the area immediately around the tip-in. :-)Yes, learn impacts idle too, and remember the even when the basic learning is done there will continue to be some learning for changes in weather, altitude, etc.Go ahead and try a few idle settings and see how they impact the idle-speed searching. No air should be able to pass. So, clearly, the "No" answer is wrong. The tps has slotted holes, can you adjust it to get to zero? I've been having problems with my sniper efi just shutting off. I have never seen issue when CTS is below 120 degrees. I believe that for the HyperSpark the Reference Angle should be 57.5. Chris, Since your target is probably more like 700, and since 2400 is way over 1700 RPM, it's going to leave the IAC in the park position.Buckle down and find how air is getting into your engine. I have changed my roc/tps to 7 from 15 but that only took me out of learn mode. However based on your reply I connected the Fuel Pressure gauge and Handheld shows plenty of fuel so I dought it's an issue there. any advise would be appreciated. It's the same one that Holley puts in their Sniper Master Kits and I've never heard anyone with anything but good things to say about it. I followed the instructions and set the IAC to 2-9% when warm with idle at 850 RPM. I've increased the IAC rampdown time to 8 seconds to try to combat this, but wondering if it will correct itself over time or if I need to possibly replace this TP sensor. After only running for about 15 minutes or so the system starts to fail stalling the motor. If you did not rotate the distributor to set the actual timing to 15 that might be the only issue. Idle quality is great, RPM is good, sometimes IAC is now between 2 and 5 exactly where it should be. The whole topic of using the Sniper TPS for transmission control is one deserving of it's own article but I'll try to summarize a bit here. Genuine Walbro fuel pumps are virtually bullet-proof. Take it a step at a time. Is this an issue to worry about? Once it commands that high idle I haven't found anything to return it to normal, other than shutting it down and restarting. But they are 100% committed to your satisfaction. No power at the programmer and no fuel pump running. If you go too low then it may stumble or even stall when coming off of throttle. If you find that adding 5-10 degrees of advance helps then it's time to do reconfirm TDC. Idle quality is great, RPM is good, sometimes IAC is jumping around from 35 to 60. I did buy the Sniper from you guys and the service was fantastic. Either the Walbro pumps you are getting are not genuine (lots of forgeries being sold) or else you have something that is killing them. He has walked me through every question Iv. When you open your IAC to 30% you are naturally going to have a high idle condition. But I can tell you that for most people who try this it introduces so much RFI onto the Sniper that it never works right. Your task will be to find that. Even at 0% it's sucking a bunch of air through the IAC port. Check the Distributor Tach Connection to the EFI. I enalble the idle timing control and fired it back up Iac was at 32% but it would come back down after a bit to around 26%. In the time it takes to add your email address you can be at the top of the heap for getting the latest information from our authority. In the Wizard, select the stock cam setting. Thanks. The weather in Ct has finally improved and I have put about 60 miles on the car with the Sniper system. I think in some of the Wizards with the handheld it doesn't use 57.5 as the default. There are six different acceleration enrichment tables that you can tweak and that may be the way to go. The hold position is part of the response that keeps the car from dying when you come off the throttle. Did you find this enlightening? Holley Sniper high RPM - IAC problem? IAC Pos.% = 0 It will drop down to 400 RPM then climb 500 and then shoot to 900 and then come back sometimes two or three times then catch it self an idle just fine again. Shut off car/restart and it's back to idle at Yes its at 95lbs, needless to say he promised a new regulator would be in the Setup: 1965 Impala SS; ZZ6 Crate Engine, EFI Distributor. The last pic is with the car in Drive. To finish, I rather tightly twisted the TPS signal and ground wires all the way from the controller to the Sniper TPS and very carefully routed them away from sources of RFI. applies here because it is so important to realize that just because the IAC Since the load is more of a wave that increases the most initially and then decreases again, the ECU is doing really well to get the idle under control in only two or three over/under shots as you describe.You don't mention if you have your Sniper ECU controlling timing. If your TPS is at zero and your IAC is at some random number above 8% (but not exactly 30%) then for some reason your engine has not met the conditions to ramp down to target idle. Sniper EFI Idle Tuning - Holley Motor Life On startup- cold or hot, I get a 2 second high idle of about 1500 RPM before normal set idle of 750 RPM happens. The next time it happens is the perfect opportunity to find the problem. NOTE: Do not attempt to set the target idle speed and IAC position until the engine is above 160F! Sniper EFI Initial Startup and Troubleshooting - Holley Thanks again Chris, your help has been invaluable.If anyone is considering going EFI, Chris is the man to chat with. There is no real mystery here. That's not the IAC Hold Position, it's a percentage value. However, I have what I will call a whistle at a throttle position on 35 - 50. Could be a bad IAC motor, replace it and see if that solves the problem. Any idea's? I certainly appreciate your frustration (as well as your wife's!) Short drives is fine then it'll I have seen a couple of videos on you tube of the same issue but they don't seem to have found the cure.I hope it is not a computer problem as I have already replaced the entire system because of another problem. I did check for the lightning under the hood but all was well. Relatively new Sniper EFI install on a '69 Mustang 302. )Since this isn't a consistent issue with all Snipers that tells me that different IAC settings tend to make the whistle. IAC looks good once it finally s fires. I figured out I was going the wrong direction when I was messing with the AFR programming. Both Sniper and trans controller grounds were direct to the battery ground, as they should be. That changes almost instantly as the engine revs.Since the learning algorithm requires some time exposure to a certain condition to make larger changes, that half-second makes only the smallest impact. Installed sniper on 65 galaxie. Member List; Calendar; Forum; Holley EFI; Sniper EFI; If this is your first visit, be sure to check out the FAQ by clicking the link above. Holley Sniper EFI Problems: Best Fixes According to Manufacturer To keep it running in gear, I have to bump the neutral idle up just over 1000 RPM. Incorrect connections will result in excessive resistance. This car has never idled under 900 without stalling with 3 carbs and does the same thing with sniper edit. To be honest, you sound like an ideal candidate for Sniper ECU ignition timing control. Robust, feature-rich multi-port EFI systems offer easy plug-and-play late-model V8 engine swaps. would correct it (as it has for a multitude of other drive-ability issues) but this one little glitch seems out of it's range. After much diagnosis, I ended up replacing the intake manifold gaskets. Then your low idle problem will go away. Wish I had bought my sniper from you, but unfortunately didnt. Sometimes an engine can produce enough vacuum to pull the secondaries open slightly. The fix? And all too often we don't take that extra step of using a piston stop to ensure that the timing pointer is on zero when the engine is truly and exactly at top dead center. When you key on, you will hear three distinct sounds: The ECU initializing the IAC, the fuel pump priming, and the injectors firing their prime shot. Be aware that there is a spring behind there and a diaphragm that you don't want to tear. But he kept having problems so eventually he did a complete check and then he found the problem. Does this seem reasonable and how hard will it be to get the idle and off-idle performance correct? holley efi. This minimizes installation time and packages really well on a diverse group of engine applications.