Getting the throttle blades and IAC to work together will keep your fuel injected hot rod running smooth and predictable. You can manually set it 57 after you run the Wizard if required. School's out for spring break this week though so I'm covering for employees on vacation. I never had a problem with this. Drives just fine but won't stay running unless I keep my foot on the gas. I managed to get the IAC down to around 0% - 8%is this good? Do you have a PCV on the engine? If your mixture is too rich, it means there's too much fuel and not enough air. The problem I'm having is I cant get the IAC to drop down off 100%. 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. In that case, and if you have an EGR valve, I might be suspicious of something going on there. I looking for your expert opinion. You have to remove all hoses in order to debug the problem. Price Point: $$$. The jack-rabbit start can usually be minimized by adjusting the throttle linkage. I'm new to the efi thing and any help would be seriously appreciated. Then, when you experience the high idle, note if the IAC number has increased. It's going to be really difficult to nail down the problem with the several simultaneous changes that you've made. If the TPS is even just 2%, the IAC will go to the hold position (normally 30%) and will not change until the TPS goes back below 2%.If you create a datalog you will be better able to confirm if something is not working correctly. All in all, considering the system has been installed for less than 2 hours drive time we're BLOWN AWAY at how quickly it is "learning" this engine. This curve runs fom -40 degrees to 260 degrees, and gradually reduces the RPM along that range. I cut and heat-shrink wrapped the 5V wire and then ran both the signal and ground wires all the way back to the transmission controller. any advise would be appreciated. If I rev the engine a couple times in neutral it will finally return to idle & usually will not do it again for the rest of my trip. Contact whomever sold you your system or Holley directly. Should I just disable idle timing control? If the TPS is 1% or below then the air is coming from somewhere else. It only comes back to normal if I turn the engine off and on again. I installed another return spring for the rear plates problem solved instantly. I think in some of the Wizards with the handheld it doesn't use 57.5 as the default. Both Sniper and trans controller grounds were direct to the battery ground, as they should be. When you open your IAC to 30% you are naturally going to have a high idle condition. Last night I tried setting the IAC and had the same problems after it's warmed up. If I adjust idle screw out to get the tps to zero or even 1% the engine will not idle. Rpm with 4-8 iac but it still shows red and shuts off randomly at idle and it won't even drive 2 miles without shutting off. Check fuel pressure too (. 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 chased that gremlin for about three weeks and was convinced I had a bad throttle cable. 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. The engine runs beautifully, with perfect idle at 650 RPM, but every now and then I hear the IAC give a sort of "snap" and the idle is at 1200 RPM. The 5-6 times it has happened now have been after the car has been running for at least 20 minutes. to. I will a, Scott has been very helpful and informative on guiding me through the purchasing and installation of my terminator X max system. I' m going to put the 3rd new pump this coming friday. If you haven't installed a When I cover it with my hands, it gets quieter. Please let us know how this works out for you! The latest was changing the power brake booster.Today I drove it to work and no issues at all. Is this an issue to worry about? 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. One additional wrap on the secondary coiled shaft spring is all that's necessary. the gas it catches itself and runs fine at slower speeds. Changing the rpm curve and target rpm has no effect. That It works instantly for him.If that fixes your problem then you have a starting place. Bryan McTaggart 02/28/2023 news Now it's at 5% on a big cam 440 Mopar. You're going to have to clean up the wiring in your engine compartment, In particular, look for spark plug wires that might be running near your throttle position sensor. I, too, wish you'd bought your Sniper from us! The Super Sniper will allow you to monifor fuel pressure if you add an electronic sender but this is not an option with the standard Sniper. Remember that as an EFI System Pro customer you have access to me at any time via my cell phone. This minimizes installation time and packages really well on a diverse group of engine applications. Wish I had bought my sniper from you, but unfortunately didnt. Throttle Tip-In puts you in a part of the fuel map where you stay for only milliseconds at a time. 34K views 1 year ago Holley Sniper How to Set The IAC Idle air Control in 5 minutes or less. normal city driving, I no longer have other problems I had with the original If not then I think you are going to find that this will solve much of your problem. Setup: 1965 Impala SS; ZZ6 Crate Engine, EFI Distributor. However, it is a good question so I thought I'd throw a few bits of info out there that I think might help.First, I believe that you may have a basic misunderstanding of what is being referred to sort of generically as AFR. When I covered the IAC with my finger, the RPM dropped so low it stalled. Were the additional load a simple step function it would be challenge enough for the ECU to gracefully increase the engine speed without overshooting. You mentioned going from 13.5 to 14.2 but you'd want to go in the other direction--maybe to 13.2. Your mechanical advance will naturally change the timing a bit but it should be fairly close. These are "transitional" cells, and you really have to make the effort to learn in these areas of the map. Yes its at 95lbs, needless to say he promised a new regulator would be in the The idle is 1350-1400 with the idle screw at initial contact. Chris thank you for the info. My sniper is doing two thingsFirst issue, the idle is set at 800 and will idle fine, then There is a glitch in the system. Should it not do the opposite and do this on a cold start not warm. Price Point: $, Advanced throttle body injection systems capable of transmission control and more. But I am having troubles.When stepping on the accelerator slightly with idling, it will be 2000 RPM all the time. On startup- cold or hot, I get a 2 second high idle of about 1500 RPM before normal set idle of 750 RPM happens. You can re-enable this after you have completed this idle speed adjustment process. This is normally used as an A/C idle-up circuit. 30 minutes later CTS reads 161, start engine Idle is jumping from 450 (almost stall) to 1500, IAC is jumping all over 10 90. At idle my IAC is 3-4, AFR around 13-14, TPS is 0, timing 15-17. Installed sniper on 65 galaxie. The Sniper Quick-Start Manual provides the following instructions for setting the idle. It's a Chevy 350 bored .030" over it has a cam in it what I was told is the cam has the firing order swapped. If the connection is loose it will cause the system to shut fuel off because the signal telling the EFI the motor is turning stops (to prevent excess fuel from being dumped in the motor). 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 With an assistant pressing the accelerator, you need to make sure that when the accelerator is pressed to WOT that the throttle blades are fully opened, and when accelerator is lifted the linkage is fully at rest against the idle speed screw. Closed Loop Compensation rises to 100%, Do I just keep pushing it the same way to Good luck! Good afternoon Chris, thanks for taking the time to help all of these folks that didn't purchase from you- myself included!The issue I seem to be having is at idle in both park/neutral and drive. I can tell you that when things aren't working the way you wanted them to work that nothing beats knowing for-sure that you don't have a fuel supply problem. Without it you are working in the dark. Interesting situation you have. The only way to confirm RFI problems is by doing a data log. I'm going to jump out on a limb here and say you either don't have adequate fuel flow or pressure. Let me start with the engine not starting until you press the throttle. However, I have what I will call a whistle at a throttle position on 35 - 50. The link above includes the option to buy a -6 AN I keep doing that with the same result. Idle was around 1000 mark and iac 0. Eventually the IAC will drop back to zero, I'll readjust it to 850 RPM & 2-9%, and then watch it steadily climb again. Thank you chris for for getting back to me on this matter.I'm using russell hi pressure gas line to feed the gas up to the sniper and using the stock steel gas line that use to be the feed line for the carb to return the gas to the tank. If you go too high then the motor will not return to your target idle when you come off the throttle. If I put the vehicle in gear the idle gets higher with temp. Thanks! Intermittent stalling usually points to radio frequency or electro-magnetic intereference (RFI/EMI). shut truck off. If you see that the ECU is commanding the IAC to 0 but there is air entering the IAC port then it's time to refer to my article on IAC Testing Procedures, Hello,I installed my sniper system on a 65 mustang, with a 302. Car has run perfect every time and has never hesitated or stalled since. Stupid question, but where do I see if it's entering Learn mode? But there are several degrees of play there in which it should still work fine. Thank you. It starts cold fine, its just when its hot. ChrisI finally got everything resolved. Featured Products EFI - Fuel Injection $2.59 - $6,499.95 2179 Products View Parts Sensors If you haven't confirmed that they it is worth checking. I think you'll be all set! As you see above, the Sniper is going to dump in a maximum amount of fuel at zero TPS, begins to remove acceleration enrichment at 60 percent TPS, and then removes all acceleration enrichment correction at 100% TPS. (Do this while you are cranking.) I have replaced the IAC motor and the problem remains. I would suspect something is coming loose causing a stop to the EFI system/Fuel flow. The Sniper EFI remote IAC (Idle Air Control) and plug is designed to gain installation clearance on some Sniper EFI 2x4 installations. I presume your idle speed table doesn't increase at 200 degrees? 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. Thanks for the information you have provided on this site. After manually making the sensor go through the full range a few times, I reinstalled it and now my TP will read anywhere from 0% to 4% when I key on. 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. 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. Camshaft is M-6250-B303 .480 lift intake & exhaust, duration at .050 is 224 degrees for intake & exhaust. and when I close the IAC's hole with his finger, the engine is normal.The data on the touch screen I see are:AFR, A / F = 35.6 Running a bbc with coil - my timing is perfect. If your RPM is 2000, your TPS is 0, and your IAC is not closing, then there is some problem. As soon as I got the new one installed and wiredit fired right up and did everything it was suppose to do with no issues. Add To Cart. I've not heard of any others with this exact issue so I don't think it is a common problem. Yes, it will talk to you--but not with words. 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. me know how it works for you. 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. All times are GMT-6. Engine has never stalled with Sniper system, once placed in Drive it just goes!!! Don't make any changes more than about 10% and keep the same basic shape as the original (High/flat below 20 degrees, sloped downward up to 180 degress, and then flat again above that.) Capability Range: Professional When running it will only stay in closed loop and learn at idle. Any idea's? If so remove it. But I think it is safe to say that you are now at a point were some manual tuning is a good idea. Drop the IAC parked position a bit at each temperature point and sort of back into the solution. Hi Chris, I have a lean stumble on throttle tip in 2-3% tps taking off from a stop light the afr will go to 19afr and the engine will stumble for a split second. Is there any chance that your timing has changed since you installed your Sniper? Target AFR, A / F = 13.5 From herethe cycle continues and I am If there's any run time on your current setup the Sniper may have some bad learn data due to what appears to be timing issues. Then you can take a close look at the IAC and see if it is opening. Any ideas here? I followed the instructions and set the IAC to 2-9% when warm with idle at 850 RPM. We are running a Sniper on my mates 355ci small block V8 & so far he is very impressed ! If you hit the gas it pops & backfires through the throttle body. Mechanical Fuel Pressure Gauge on the inlet of your Sniper, now is the time. I also raised idle at Park a bit with the idle screw. 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. Fuel Prime Multiplier is primarily a benefit to throttle-body based EFI systems. When the lambda is 1.0, the displayed AFR is 14.7;1 REGARDLESS OF THE FUEL. Otherwise, if removing the air cleaner eliminates the whistle then try to use a thicker gasket or try lightly greasing the gasket. If you don't have a working coolant temperature sensor then it will never bring the idle speed down. So what--you're never going to drive in minus 40 degrees, right? such high fuel pressure. Suddenly, the engine accelerates alone, hears a great deal of air being sucked in, This increased idle speed is triggered by grounding the orange wire in the 10-pin I/O harness. They tell you to ask call Holley. Holley EFI Electronic Fuel Pressure Gauge, article on choosing between Sniper and Terminator X throttle body solutions. Pw. The symptoms I had was a low cold start idle and going lean coming to a stop. Unfortunately I did not buy my sniper efi from you. The data that you provide shows that you have at least two problems. Also, I was seriously rich at idleso rich it hurt your eyes. When this occurs, I sometimes can shut it down and it will return to the correct settiings. :-)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. Duration @.050 is 240 intake 246 exhaust with .574/.578 lift. 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. 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. Can the return line be an issue?So far this sounds like an ideal setup.>I have had 2 faulty gpa-4 255 walbro pumps go bad. Genuine Walbro fuel pumps are virtually bullet-proof. I did notice that when I thought I had it set The car would idle, I could hit the gas rev the car up and it ran great I also noticed two nice black spots on my garage floor from the exhaust. 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. I did all of this before seeing the link you sent. have noticed on the hand held is that Air/fuel Ratio rises to 20 +/- A/F and the My IAC was constantly at 100% at idle. Copyright 2022 Holley Performance Products, Inc. All right reserved. )So before I hook up another gauge to see if the Auto Meter is bad (assuming I can find a 0-100 test gauge in my shop). It's not that they (or any other manufacturer) is 100% perfect. I am new to the EFI scene but want to learn. All times are GMT-6. With the vehicle in neutral, adjust the idle screw until the IAC Position reads between 2 and 10%. If you go the other way then you might find that the IAC zero's out when the fans are off. Cycle the ignition as instructed by the handheld and then navigate to the distributor setup screen. If idle drops below 800 it wont come back itll chug around 300 rpm for a few seconds then die. At low levels RF interference will often reset the ECU so quickly that the engine will not stall. 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. Some suggestions: i did have the same problem.try lengthening the lever of the throttle.meaning the length from the center of the throttle to the point where you attach your cable or your rod from the peddle. I' m going to put the 3 rd new pump this coming friday. Holley Sniper Iac Delete That is what I really respect about Holley. Then your low idle problem will go away. Chris---I am contemplating replacing my Holley 750 on my new low vacuum 600 HP 496 with the Holley Sniper FI system. I guess we can't have everything. This is a mighty big subject for a blog post reply, I should probably start doing some videos on this. I recently bought the car with the EFI system on it. is the fuel pressure. Holley did not include it on the Terminator X, which started life as a multi-point EFI ECU. knowledge with the sniper efi setup. I figured out I was going the wrong direction when I was messing with the AFR programming. Realize that when you drop the throttle, the engine enters a condition it will only see for a fraction of a second at a time. If the IAC number is increased during this high idle, review the points about high idle from tuning issues. Please give this a try and let us know how it works! By the way your site and your accessory products are nice. Therefore The iac will always be at 10% now, correct? Unless you have ignition control enabled, that is the only thing it can do to reduce the idle.Realize the only things that can cause the car to idle up as you describe are air and ignition advance. The car cruises fine, and if I was to keep idle at 2000rpm the issue wont happen, its only when the car tries to ramp down to idle position.Thank you for your help, any advice would be appreciated.Thank you,Eric, Whenever we see the AFR go to "Heating" that is an indication that the ECU has been reset. 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. When the secondary throttle blades are centered in their bores and pivot freely, an additional return spring is not necessary. Im thinking a faulty TPS. Should the iac% fluctuate? The fact that it ran so (at times) with 90+ PSI fuel pressure is a testimony to the Holley's closed-loop technology. If you have an installation or start-up issue that is nagging you then please use the comments section to reply and we will gladly provide more information that we hope will be useful to you. One of the most common symptoms of a Holley Sniper EFI problem is an air/fuel mixture that's too rich or too lean. Generally, one of two things: a stuck throttle or noise on the TPS signal. Enjoy your Sniper! But after sitting static idling for a little bit, the IAC goes to 100% & stays there. Any suggestions would be appreciated. Ensure that the secondary linkage is completely closed (both visually and manually.). The motor has 376hp at flywheel and the car is a stick shift. When I drive with warm engine the IAC is at 30% when pushing gas, but shouldn't it be at 0%? Is this normal ? May God's grace bless you in the Lord Jesus Christ. MSD pro billet and 6AL box Physially manipulating the linkage by hand will generally reveal if you have a sticking linkage that is preventing the TPS from returning from zero. When I am coming to a stop, the rpms will hang at 1200-1500 rpms. Full product line and accessories at excellent pricing. I called support line he said he would have to look into it and call back. If you patiently adjust this over the course of days you will get it just right.Again, glad this is working for you and look forward to a good report in the future! Once you know that then you can work on those problems. I've made all the adjustments, all the settings, and the IAC issue is driving me crazy. Check the Distributor Tach Connection to the EFI. Ultimately, it is about making the pedal softer, particularly at initial throttle opening. If I read it correctly, the solution from the other thread seemed to fix a constant 300 or so RPM increase. Across the board, all of our customers say how impressed they were that it started and ran right out of the box just by following the simple installation instructions. By the time I was near home, the idle in Park was 1050, IAC 0. Advanced throttle body injection systems capable of transmission control and more. This curve turns the idle speed down as the engine warms. Capability Range: Moderate But as you see from the recent revision I did above you seem to be having a fixable issue. If you have somehow overlooked this, start here: Holley Idle Speed Adjustment Instructions: Once the engine is up to operating temperature, the idle speed can be set to what was configured in the Wizard. This car has never idled under 900 without stalling with 3 carbs and does the same thing with sniper edit. 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. Yes it is controlling the timing and I had issues at first and it controlled the idle just fine. We are using Target AFR of 9.0: 1, Fuel Base approximately 40% higher. I.e. 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. I'm wonder if the iac can cause this. I have a 406SBC that does most everything right with this sniper setup. I would disregard any correlation between idle control between the Stock and Street/Strip setups. Worst case you'll have a spare on hand, and if the TPS is faulty you will have solved the mystery. I have an entire article on choosing between Sniper and Terminator X throttle body solutions and while Sniper is still a sound choice for some applications, Terminator X (with transmission control) is hands-down the way to go for those who need that. The broad consensus has been that the Sniper is an amazingly straight-forward install and starts and tunes as expected. hard start about 1/2 throttle from stop it bogs down after 3 or 4 seconds.What I Well, it turns out that with the current firmware this throws the IAC control into a bit of confusion. The broad consensus has been that the Sniper is an amazingly straight-forward install and starts and tunes as expected. Ilike a few othersam having idle issues. When I start the motor I have to push on the accelerator pedal for the motor to start. :-). In most cases the IAC (Idle Air Control) circuit is the source of the whistle. As I said above, you could have a bad IAC, but then again, the IAC might be fine and there's a deeper problem such as RFI noise causing the issue or a vacuum leak that is confusing things. This page was generated at 12:25 AM. Your AFR is pegged lean. See these. They also recommended that their ground be spliced into the Sniper ground as close to the Sniper as possible. You will need to change the -40 degree idle speed setting again but I recommend not touching anything else. Only show this user . 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. Idle Tuning is a very important part of tuning any EFI system, especially our self-learning units like Sniper or Terminator X EFI. If you're having issues with your Holley Sniper IAC getting stuck at 20, there are a few things you can try to fix the problem. Second, Holley just released over the weekend a video on how to implement a flex fuel sensor on their HP and Dominator ECU's. 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. While this video is not meant for the Sniper EFI user it does provide a great overview of how your ethanol tuning adjustments must be made not only to the base fuel map but to the other configuration settings. Let's start by not assuming anything. I believe that for the HyperSpark the Reference Angle should be 57.5. I would suggest at that point you need to contact whoever is providing your tech support and find out why the default values are not working for you. While adjusting the screw if the TPS position reads begins to read higher than 0% cycling the ignition switch will recalibrate the TPS back to zero. EFI parts, including the throttle body, and the problem persists.Please give me a hand. That disappears as soon as the throttle is pressed and then you immediately revert to your timing table.You can certainly use the compressor to initate the IAC Kick, but remember that this is just a temporary idle boost to ensure that the engine doesn't die when the AC is first turned on. However based on your reply I connected the Fuel Pressure gauge and It shuts off when coming to a stop sign, at any cruising speed and romdomly at idle in park but never when excelerating. When I put it in gear, it drops so low that it will stall if I don't add throttle. We will definitely be sticking with Holley from here on out for future retro-fits. The engine might run hot but if the timing is right it should keep that heat in the engine--which is where the damage turns up. The Fuel Base map is perfect, the car works well, runs well, running through the streets, the car is great. But after sitting static idling for a little bit, the IAC goes to 100% & stays there. carburetor setup, but it does blow when I can't jump on the highway like I use That initial rev is going to be determined by your IAC Park Position. 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! I can have it working fine (5% to 10% at target idle at operating temp.) Simply use your handheld controller and go to the Tuning > Advanced > Advanced Idle > Idle Speed screen and click on the Idle Speed Curve function. I would suggest you take a look at that if you haven't already. Running new vintage air system so the is only a single power wire to compressor thats why I asked if I needed to run input wire to ac relay or if iac would pick it up fast enough(which its not). That, I am afraid, is going to involve a little bit of luck if you don't want to create a 250 MB data log. This will go a long way to improving your fuel map without manually adjusting the acceleration enrichment. That is the IAC hold position. The engine has 14: 1 compression ratio, we can not use gasoline. engine works beautiful, the car runs a lot, but suddenly, the engine does that.