holley sniper efi iac problems

Somehow air is entering the engine that was not entering the engine when you originally set the idle speed screw. Definitely not 90. I have a Holley Sniper EFI with HyperSpark ignition. Give that a go and see if you don't make some progress! To figure this out it's going to be important to gather a bit more data. For someone in your position, it will become an indispensable tool in your tool box. Often, folks will say, "I did everything you said. That is not a huge problem but it just means the IAC has no ability to lower the idle beyond what it is running at that point. Next, reach down into the secondaries and push the butterflies closed. We are using Target AFR of 9.0: 1, Fuel Base approximately 40% higher. I have heard some guys complain that the idle is too good and they can't hear their cam anymore I'm kind of like that. Consider adding fuel in the AE vs TPS and/or AE vs MAP ROC tables in the area where the stumble is occuring.Since this is happening at such low TPS levels it is possible that your engine would prefer a lower (richer) target AFR number at idle. 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? Installed sniper on 65 galaxie. AGAIN This is Intermittent meaning on a recent trip I stopped 3 times and issued occurred once. 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. I'd really appreciate some help. After talking to Holley tech, I replaced the factory regulator and problem solved.The regulator had what appeared to be a film or something almost clear embedded in some of the screen, maybe from factory or from install, but that was my issue.PS : this page and other forums have helped me a lot. P.S. 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. I ask because I'm using a PCV valve with my Sniper and have random idle issues as well. View Holley Sniper EFI Self-Tuning Kit - Shiny Finish. They also recommended that their ground be spliced into the Sniper ground as close to the Sniper as possible. I installed a Holley Sniper on my Ford Maverick 302 V8. By the way, this is a new installation on a 69 Camaro, stock 350, dual sync, etc. 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. NOTE: Do not attempt to set the target idle speed and IAC position until the engine is above 160F! Holley Idle Air Control Motor Idle Air Control Motor Fits the Following Applications: Sniper EFI 90 mm, 92 mm, 102 mm Throttle Bodies Digital Pro-Jection Systems Avenger 4-bbl TBI Commander 950 Terminator TBI The second thing to realize is that even after you get it just right, you need to keep an eye on the IAC number and reset the idle if it gets outside the 2-8% range when idling when warm. Chris I am having a little different idle problem I did your -40 thing and that help with high idle but my problem is it idles fine until I drop it in gear and it stumbles a couple times catches up and then idles fine again. Keep in mind that at 60 miles the :-). You can manually set it 57 after you run the Wizard if required. When you have the issue you should disconnect all hoses and plug the ports on the Sniper. What I can't explain is why your TPS is acting so randomly. I notice at 2-3% tps the iac is 18-25% and it stumbles, when the iac gets to my hold position of 30 it stops. I think you will find that it will learn its way through this. The weather in Ct has finally improved and I have put about 60 miles on the car with the Sniper system. 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. At any rate, once the setting was moved up, the RPM jumped right to the target RPM and was solved. If you use your handheld to go here: Chris's Idle Speed Adjustment Instructions*: *Note: If you are using your Sniper to control ignition timing then I recommend that before you start this process you disable idle spark control If you are trying to do this while the ECU is simultaneously trying to bring your idle under control by adjusting the advance it is going to be counter-productive. This may require shortening or lengthening a rod. Thanks in advance for any advice. 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. However, I can't think of a single one that was because of low vacuum. You mentioned going from 13.5 to 14.2 but you'd want to go in the other direction--maybe to 13.2. :-)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. Short drives is fine then it'll started up the engine. Several good bits here. Engine Startup Tuning for Sniper and Terminator X Stealth Owners During cruising at 30 miles and release the gas pedal the engine revs at aproximaly 1500 RPM and it won't drop. I'm new to EFI and have no idea what to try next. check, I guess after reading everyone saying how great the system is after The first thing I'd do is check your fuel pressure with a gauge like this. datsun sniper efi Holley RetroBright This 1974 Datsun 620 Bulletside Cruises With The Help Of Sniper EFI Bradley Iger 01/13/2023 features Latest News sweepstakes 2023 Hemi Engine Sweepstakes Gen III Hemi Enter To Win Holley's 2023 Hemi Engine Sweepstakes For Your Chance To Win A 600+ Horsepower 392 Stroker! Do I have to hook up sniper ac wire to relay or should iac pick up idle? This page was generated at 12:25 AM. While confirming, in the handheld ensure that the Reference Angle is set to 57.5 and that the Inductive Delay is set to 100. Once you've done this, the next natural step is to transfer the learn table to the base map, then go in and smooth out the sharp edges, which are going to be at these transitional states. It runs perfectly fine other wise. If the screen shows iac at 0 and you block the hole to find it open what does that mean? Could the IAC be broken/malfunctioning? That is what I really respect about Holley. The timing can drift 0-30 degrees just due to the width of the rotor tip. THANK YOU for the "First--Check Your Idle Speed Curve Setting!" As you have noted, each time the idle goes up. I didn't find your site until I was having trouble. The Sniper EFI Manal says not to but many EFI installers have informed me that the transmission only reads the 5V TPS signal from the Sniper EFI & does not draw any power so will not affect the Sniper EFI TPS output. Thanks for any help. It's hard to know what the previous owner did right versus wrong. A good example of why it's so important to run a good pre filter in the fuel line. applies here because it is so important to realize that just because the IAC 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. I recommend confirming there is no throttle linkage issue first. I installed Holley Sniper on three other Mavericks here in Brazil and the problem also exists.I did not make any changes to the parameters, only on Target AFR and the correction on the Idle Speed Curve chart. We do that but most places don't. TPS 0. This is more of a bit of a reality check. 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%. Even 50 RPM can make a difference in how much impact the transition to Drive has on the idling engine's ability to stay at a fixed RPM.I would not recommend it in this situation but anytime a "kick" in idle speed is desired that is easily done by setting the kick value in Tuning > Advanced > Adv. All times are GMT-6. As I have it set right now, my idle at park is in the high 700s and my desired idle in gear is set at about 700 cold (80 degrees) and gradually lowers to 590 once engine temp reaches 160 degrees. The data that you provide shows that you have at least two problems. Contact whomever sold you your system or Holley directly. In the context of the Sniper the AFR that is being displayed is the AFR of ethanol-free gasoline based on the lambda that is being read by the AFR. Capability Range: Advanced Explained: Holley EFI Sensors and What They Do back to trying to zero down an idle. Capability Range: Professional It won't take much! If no air is passing (and the idle doesn't drop) then your IAC is working. Hello. Throttle body mounted ECU - no extra boxes to mount. I did check for the lightning under the hood but all was well. 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. 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. If you have performed the adjustments above and still have RPM issues, it's time to look for clues. Good luck! 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. Supports up to 650hp with Four 100 Lb/Hr Injectors! Perfectif you have the original synchronous linkage. If you feel you have no other choice but to run a Sniper and stand-alone controller then you can give this a try. If your mixture is too rich, it means there's too much fuel and not enough air. 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'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. There's a procedure there I can share with you if you'd like.. Idle Tuning is a very important part of tuning any EFI system, especially our self-learning units like Sniper or Terminator X EFI. I asked him a million questions and waited a long time to save up before purchasing the system and I have asked a lot of questions throughout the installation process. So glad this was helpful. Next, clean the IAC and all related parts with brake cleaner. Holley Sniper EFI 550-552 Holley Sniper EFI Autolite 1100 - Gold If I try and get the 2-10% i get all the way up to 1200 rpm. = 2.34 A few, however, get tangled up getting the idle control working just the way they want. Did your process to adjust idle to 860. Properly configured, the Sniper does a fantastic job of responding to the transition from Park to Drive. A couple of possibilities that come to mind in order of likelihood: Im having an issue with what I think is the Iac. I never had a problem with this. Let I have checked the pink wire and it is at .001 volts when key is off. The "PC Text" indicates what will be shown on the PC/Laptop data monitor or data logger. He said they have been having an issue with these lately. Could be a bad IAC motor, replace it and see if that solves the problem. Drive great and idles perfect at stop signs. There's nothing wrong with manual tuning, but at this point that is just compensating for an inadequate fuel map. That initial rev is going to be determined by your IAC Park Position. I have a 406SBC that does most everything right with this sniper setup. The throttle blade adjustment is at 2-6% at hot idle, and with warm engine 185F. Advanced throttle body injection systems capable of transmission control and more. Bolt-on carburetor style EFI for your classic car or truck. 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. 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. 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 is reliant on the data acquired by the included wideband oxygen sensor. But before you adjust the ECU to lean the idle out, first confirm that your fuel pressure is right. That way you can get into that part of the table that needs tuning, and you can watch your learn numbers grow. Thank you so much for your follow-up. PDF Sensor Diagnostics and Statuses - Holley Tps is saying 26% when it at 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. When the system is up and running the fuel pressure regulator inside the Sniper is making a rattling sound like a shaking a paint can. Physially manipulating the linkage by hand will generally reveal if you have a sticking linkage that is preventing the TPS from returning from zero. You are looking in the right area but I would probably not change the ROC blanking. It sounds to me like it is way retarded.In the event that the timing is right then take a look at your AFR--the actual AFR, not the target. But I wanted to go ahead and answer this so that it would make sense to someone who might not go that route.I think the first thing I'd do is try another pressure gauge. Part# 538-13. When the idle speed screw is turned all the way out there should be just enough room between the bore and the blade to catch your fingernail. It will need to see it again and again. 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. The IAC is hanging open and not really at 0. (Do this while you are cranking.) I have tried your 10-step idle adjust and ive adjusted the idle curve. Hello This item: Holley - 543-105 EFI Idle Air Control Motor , Black $71.72 Holley Sniper EFI 870001 Throttle Position Sensor $34.60 Holley 860004-1 92MM Sniper Throttle BDY $223.93 Customers who viewed this item also viewed Page 1 of 1 Start over Holley EFI Idle Air Control (Iac) Valve Motor 30 13 offers from $79.56 I.e. 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. To be honest, you sound like an ideal candidate for Sniper ECU ignition timing control. Chris thank you for the info. When I am coming to a stop, the rpms will hang at 1200-1500 rpms. Hey Tommy, we've got at least one thing in common. Another suggestion is to add an extra turn to the spring built into the linkage to increase the closing force on the throttle shaft. Holly offers a very nice Analog-Style Fuel Pressure Gauge that is another option. I've helped folks work through a number of challenges with their Sniper EFI System installations. It is good to at least know that the Sniper fuel pressure regulator can have high pressure failure issues (contrary to what I posted to Scott back on April 13th!) Maybe here will work better ?Sniper High Fuel PSIMy fuel psi is over 90 according to a brand new Auto Meter pro mechanical gauge tied in at the inlet to the Sniper using an AN adapter.I did the search function on here and found a similar high PSI issue that was fixed by clearing the return line.I have checked the return line hose for kinks and have removed it and blew thru it without any back pressure. Since the shield was put on, not a single problem, not one. I did change the -40 thing also. The Sniper EFI system looks at the closed-loop fuel compensation required to reach your target AFR. MSD pro billet and 6AL box I have driven it a few times maybe 100 miles or so. First--besides the fact that it's not represented on the display, it is not even a parameter that you can datalog. Once it decides to come back down, it does so with no issue. 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.) Turning off and then on again, the engine returns to normal. Should it not do the opposite and do this on a cold start not warm. I followed the instructions and set the IAC to 2-9% when warm with idle at 850 RPM. I'm happy to walk you through what is required. You'll have to go back and forth a couple of times to get it just right. There are six different acceleration enrichment tables that you can tweak and that may be the way to go. Featured Products EFI - Fuel Injection $2.59 - $6,499.95 2179 Products View Parts Sensors Have you confirmed your fuel pressure at idle is 60 PSI? 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. When you open your IAC to 30% you are naturally going to have a high idle condition. These problems will go away when you do that. How can I adjust the startup speed down to about 1400 RPM? Im in Australia, so stuck the sniper on a 355 Holden engine with CD box. The AFR was pretty consistent around 13. The problem I'm having is I cant get the IAC to drop down off 100%.