The Sniper resets the TPS to 0% each time that you key the system on. The first place my eyes go when there is any issue with the idle is to the TPS value. But when you have it then you can look for exactly what the IAC is doing at that point, and if there is anything that might lead to this happening. 30 minutes later CTS reads 161, start engine Idle is jumping from 450 (almost stall) to 1500, IAC is jumping all over 10 90. So check that timing and I think that you're going to find you need a good bit of advance. But after sitting static idling for a little bit, the IAC goes to 100% & stays there. If the minus 40 degree setting is lower than the setting to the right, simply move it up so that it looks something like this: The folks who have tried this have found that their idle speed control behaves much more as they expect. If you are using your Sniper EFI System to control timing, navigate to Tuning > Advanced > Advanced Idle > Idle Spark and ensure that the Idle Spark Enabled is set to Disabled. Covered the IAC port and set idle for 850 ish. Good I used the Casper's Electronics 108103 splitter and carefully soldered my connections. Holley EFI Electronic Fuel Pressure Gauge, article on choosing between Sniper and Terminator X throttle body solutions. If not then I think you are going to find that this will solve much of your problem. I have adjusted many settings and eventually mess it up and go back to the original map. You will find a startup IAC percentage, an amount of time it holds at that percentage, and an amount of time it takes to idle down to the normal idle speed.By default, that number is 50% at normal operating temperature. This question is really outside both the scope of what we try to discuss in the comments section as well as the overall subject of this article. Sometimes an engine can produce enough vacuum to pull the secondaries open slightly. Yes its at 95lbs, needless to say he promised a new regulator would be in the If I read it correctly, the solution from the other thread seemed to fix a constant 300 or so RPM increase. When this occurs, I sometimes can shut it down and it will return to the correct settiings. EFI parts, including the throttle body, and the problem persists.Please give me a hand. Idle was around 1000 mark and iac 0. Have you ever experienced a high idle once the engine reaches 200 degrees?Ive set my idle the way you said and it works great until the engine reaches 200 degrees. This happens no matter how much I adjust the idle screw. Given the circumstances I would say that it is either the IAC motor itself or RFI but you seem to have ruled both of those out. Thanks for sharing that, Jason--great info! It could be that you've left a vacuum port unplugged, it could be that the throttle plates are misaligned (unlikely), it could be that your IAC is not closing properly. If you remove the air cleaner entirely and the whistle continues then you can rule that out. No problems with either cold or hot starts. Idle quality is great, RPM is good, sometimes IAC is now between 2 and 5 exactly where it should be. The throttle plates are misaligned. Took it for a lap around the block and came back. To figure this out it's going to be important to gather a bit more data. Wish I had bought my sniper from you, but unfortunately didnt. I recently install a sniper efi. It is made by one of the biggest names in fuel filters and sold under the Parts Master label so it is quality and great price in one. If the vendor from whom you bought the system is coming up blank on ideas then don't hesitate to contact Holley's outstanding tech support department directly at 866-464-6553. 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. The problem I believe this is creating is after I start vehicle (and its still in park), the IAC drops down to my hold percentage of 10% (since throttle % is not 0) before engine is warm and therefore causing the engine to stall out. Bryan McTaggart 02/28/2023 news Two things to keep in mind as you do that. I guess we can't have everything. 34K views 1 year ago Holley Sniper How to Set The IAC Idle air Control in 5 minutes or less. I am having an idle issue (other than that is absolutely perfect). Full product line and accessories at excellent pricing. The very first thing I would do is get ground truth on your timing. issue. I followed the instructions and set the IAC to 2-9% when warm with idle at 850 RPM. I'll bet you find that you can get it working great without any manual tuning. Hello Chris. Then it changes and will not idle down, the handheld will display 0% IAC but you can see and feel that the IAC valve is more like 100%. You have to remove all hoses in order to debug the problem. In addition to avoiding this particular problem, the total solution is much better. Yes, you are correct. Get a solid feeling for where it is when the engine is warm and the idle speed is correct. It is simply for the benefit of the user. After the start process, If the idle speed is higher than the target idle then the IAC should begin closing as long as the TPS is below 2%. Thanks for the great question! Super helpful and knowledgeable. Until the engine starts, the throttle only has one purpose: To detect you pressing it to 60%, at which point it shuts off the fuel injectors. Your suggestion to remove the PCV valve is just for diagnosis purposes, right? I installed a Holley Sniper on my Ford Maverick 302 V8. Only in the unlikely event that your engine simply won't run well enough to drive and self-learn should you consider tweaking anything inside of the first several hundred miles. But I think it is safe to say that you are now at a point were some manual tuning is a good idea. Thank you for this guide on setting IAC. This is more of a bit of a reality check. I'm going to jump out on a limb here and say you either don't have adequate fuel flow or pressure. Watch videos on installation hints and if you haven't yet, download & read every Sniper installation guide you can find online. It has gotten a little better after I drove it for three hours today.I want to save the Kik because if I get this working good then I would like to add A C and use the kick for it.Motor is Mopar 360 with mild cam and automatic. But there are several degrees of play there in which it should still work fine. I do know that the reference angle is 57.5, the inductive delay says 100.0. ?I never had my Carb Cold start RPM any higher then 1600 RPM.THANK YOU. I, too, wish you'd bought your Sniper from us! Turning off and then on again, the engine returns to normal. P.S. The team at Holley has designed the perfect solution for your problems. If this is the case then I would look particularly close at the IAC hold position and IAC ramp start.Let us know what you find and what works for you! I certainly appreciate your frustration (as well as your wife's!) If i adjust the throttle plate screw in to bring IAC in to proper range say around 7 the engine is running around 2000 rpm. I have double checked everythingincluding fuel pressureand have followed the directions to a T.I plan on trying your 10 step process as soon as I get a chance. Thanks for your very detailed question! You should get a light spray evenly distributed in all four barrels. But before you adjust the ECU to lean the idle out, first confirm that your fuel pressure is right. I also raised idle at Park a bit with the idle screw. Thanks! Try it! It is probably that your RPM above the maximum point at which ramp-down can occur. = 2.34 The following are status commands and diagnostics for sensor and various parameters in the Holley software. I installed the Holley gauge you suggested in another thread at the fuel input to the TBI, and the fuel pressure is constant around 64 according to the gauge. Using the handheld, navigate to Tuning > Basic > Basic Idle and ensure your target idle speed is set to the RPM you desire. The Sniper even has a feature that allows it to use the idle timing to control the idle speed. We offer some tips to help with that. Your AFR is pegged lean. In fact, it is those users who seem to end up most impressed with the system. Should the iac% fluctuate? That will happen occasionally, but less as time goes and on and the engine tune stabilizes. From herethe cycle continues and I am And so glad you guys are enjoying the Sniper EFI system. Add To Cart. I installed another return spring for the rear plates problem solved instantly. If your RPM is 2000, your TPS is 0, and your IAC is not closing, then there is some problem. He thought that something was wrong because when he set the idle 50 RPM below his target the resulting IAC postion was far too big. Do I need to try taping up the IAC port and setting the idle off the idle screw? EFI System Pro had everything I needed for my EFI upgrade. Does this seem reasonable and how hard will it be to get the idle and off-idle performance correct? The progressive link can be a great solution on standard (non-Stealth) throttle bodies but I would install this LAST after everything else is working perfectly. Solution #1 Put car in gear take off and the engine runs GREAT, no issues drive for 10minutes take car out of gear and engine idles correctly IAC between 2 and 5 Solution #2 Shutoff engine wait 30 seconds, turn key wait for display to come up, start engine. If I put the truck in neutral the TPMS will raise all the way up over 2000. It is always best to get the base map as close as possible before adding acceleration enrichment. If you look down and your TPS is 2% then either your throttle is stuck slightly open (which itself will cause the idle-up) or RFI riding on the TPS signal has caused the ECU to see the throttle as open and, as a result, open the IAC to the hold position. The IAC going to 30 is normal. I.e. All EFI systems need a large fuel filter to trap dirt and yet not reduce volume. If your TPS has snuck up to 2% then your IAC will be at the hold position, which by default is 30%. Once it decides to come back down, it does so with no issue. Also its extremely rich at idle. Due to when the pump i'm using now makes a loud howling noise when it gets ran for awhile and it gets at a 1/4 tank of fuel or less. When you set the Static Timing to 15, what did you read with the timing light? sniper Installation If you're installing a Sniper EFI system and almost ready to crank it over for the first time, this is the video for you! It wont fire up. If this is the case then some adjustment of the linkage or the butterfly plates themselves is necessary. Throttle body mounted ECU - no extra boxes to mount. and if you do run into any problems then, yes, the plethora of tunability adjustments available through either the handheld or the Sniper Software will certainly be enough to get you right where you need to be! If I keep the rpm's up it does fine but my clutch can't keep up with this for long.Also when I cover the IAC port the engine dies. They also worked with me on a sale I missed and price matched those parts. I have probably 200 - 300 miles on this engine and it has always done this. Just add 5 or 10 degrees of advance and see if it doesn't idle better. You could install the Holley Dual-Sync Distributor and let the Sniper control your timing. Thanks for all your help Chris! If you have it set. I think that your Sniper system is working fine but would definitely check ouf the fuel pump. That is the first thing you must find. However based on your reply I connected the Fuel Pressure gauge and Put a strong piece of tape over the IAC breather hole--duct tape or something that couldn't possibly be sucked into the throttle body. Ensure there isn't a vacuum leak causing the IAC Position to drop to 0%. But another thing to consider is adjusting your target A/F ratio. Otherwise, if removing the air cleaner eliminates the whistle then try to use a thicker gasket or try lightly greasing the gasket. While it is not mandatory, I recommend the Sniper EFI CAN-to-USB Adapter to move the data between your Sniper EFI and your PC rather than trying to do this via the SD card. There is no sense proceeding until your TPS is at zero at key-on. The on board fuel pressure regulator in the Sniper throttle body has a small filter clipped over one end . The hold position is part of the response that keeps the car from dying when you come off the throttle. Adding a wrap to the return spring on the shaft is one alternative to solving this. May God's grace bless you in the Lord Jesus Christ. In the wizard I set my Idle to 500RPM but it never got slower than 800RPM, if I run the wizard again and lower to 400 RPM then it never gets lower than 700RPM.After reading about the Idle Speed curver I checked its settings and found that the curve was 300rpm faster at every point over the temp range no matter what temp I had, I adjusted the curve to match what I put in on the wizard and now the RPM is correct, I'd say you have a bug in the wizard.Idle Speed > Idle Speed Curve: Here is where the lack of coolant temperature is going to affect you. Holley have given a new unit. Another suggestion is to add an extra turn to the spring built into the linkage to increase the closing force on the throttle shaft.