However, I always preach to never touch any of the controls on the handheld until you have a couple hundred miles on the engine in a range of driving situations. I tried adjusting my IAC up to 10deg in both directions with no change. Bolt-on carburetor style EFI for your classic car or truck. Price Point: $$, Robust, feature-rich multi-port EFI systems offer easy plug-and-play late-model V8 engine swaps. Let's start by not assuming anything. $107.95. 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. other things that might cause the idle to faulter, but this is a good start. Glad to hear that things are working well! So I have been driving it for about 400 miles now to numerous car shows and going out for cruises around town, trying to work some of the bugs out from everything we did this winter, but I notice when I take off from a stop sign or I cruise at a very low speed (say30 mph) it seems to be very boggy from no throttle to about 1/8th throttle. 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. What must remain foremost in your mind is that the only thing that can cause the idle to increase is additional air getting into the engine. Your second problem should be a bit more concerning. So, clearly, the "No" answer is wrong. I was shocked to see it at 95lbs!! Sniper EFI Idle Tuning - Holley Motor Life 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. When this occurs, I sometimes can shut it down and it will return to the correct settiings. If you hit the gas it pops & backfires through the throttle body. Thank you. Purists will sniff that these are not accurate to the tenth of a PSI. I think that your timing is too retarded. 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). Worst case you'll have a spare on hand, and if the TPS is faulty you will have solved the mystery. If it does then you can put on a heavier spring so the advance doesn't come in as fast, or use a lighter weight. But now that Terminator X is available, I highly recommend going that route. Don't know if I should put this in a separate post. At this time, TPS is 0%, IAC is 50 to 60%. He is able to get it to start by quickly depressing the accelerator to at least 60% and releasing. Nothing against Holley's method but I need to keep things simple and I do that by eliminating the effect of the IAC entirely while getting the idle speed adjusted. First, check to make sure that the IAC is properly mounted and connected. Hang in there--you can do it. I am having an idle issue (other than that is absolutely perfect). The weather in Ct has finally improved and I have put about 60 miles on the car with the Sniper system. After only running for about 15 minutes or so the system starts to fail stalling the motor. Why is this? I then saw you guys have an awesome little gauge that can hookup inline to the snipers existing fuel feed?? Really appreciate the amount of learning im getting off here. Ultimately, it is about making the pedal softer, particularly at initial throttle opening. Idles ok, runs great cruising, but from a stand still or downshifting and making a turn, when I get back into it, it wants to fall on its face. https://www.youtube.com/watch?v=2JpHlS1ymBc, If this is your first visit, be sure to 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. WIthout knowing quite a bit more it will be more than challenging for you to identify the problem and solve it.Fortunately, Holley provides their amazing Sniper Software. Though it started and ran good, it was dumping fuel and would not lean out to AFR set points. When I covered the IAC with my finger, the RPM dropped so low it stalled. Fortunately, I have an article that goes into this in some detail. Tps is saying 26% when it at idle. I will let you know what the results are. The IAC should display a 2-8% to bring the idle up to the actual target. Laptop Access 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. After much diagnosis, I ended up replacing the intake manifold gaskets. THANK YOU for the "First--Check Your Idle Speed Curve Setting!" A question I cannot get a 100% answer on is can you piggy back off the Sniper EFI TPS for an electronic transmission? It didnt do this with the carb on it. But I am having troubles.When stepping on the accelerator slightly with idling, it will be 2000 RPM all the time. Two months fighting, cursing, not getting any help from Holley OR the forum, and a stupid little tin plate. Everything was working perfectly and I shut off the engine. (Do this while you are cranking.) If I put the truck in park it comes down to idle. :-DStill, I hate to leave someone hanging so I'll try to help. We're having trouble with a Ford Maverick 302 V8, using ethanol. Holley will take a look and tell you you have RFI and wish you good luck in finding it. Ilike a few othersam having idle issues. Please check your process again and see if you can see very specifically what is not working correctly. Note that sometimes you can get into a back-and-forth situation. In addition to avoiding this particular problem, the total solution is much better. Duty Cycle% = 3 The only way to do this is by installing a mechanical fuel pressure gauge. 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 have adjusted many settings and eventually mess it up and go back to the original map. Super helpful and knowledgeable. Tuning Your Sniper EFI System for Progressive Secondary Link Use Price Point: $$, EFI Systems based on Holley's world-class Dominator and HP ECU's. I have quadruple checked my wiring and am certain it's correct. 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. Thanks for sharing that, Jason--great info! I would start by datalogging the situation and seeing exactly what your learn table looks like in the area immediately around the tip-in. If you go too high then the motor will not return to your target idle when you come off the throttle. We're never going to fill up your email box with nonsense. Both Sniper and trans controller grounds were direct to the battery ground, as they should be. Holley EFI 543-105 Idle Air Control Motor And your question is very perceptive: You must first know whether the bog is a lean or a rich condition before you can make the correct adjustments. This curve runs fom -40 degrees to 260 degrees, and gradually reduces the RPM along that range. IAC Creeps To 100% - Holley Performance Products Forums If you have any questions about the car/setup let me know. 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. It will still change a bit with weather changes and when you get into infrequently-used sections of the map, but it's nothing to worry about.Regarding your idle speed immediately after start-up, that is determined by your Idle Parked Position. Hi Chris. If the solutions suggested above are not working then you need to review my article on IAC Testing Procedures. Should it not do the opposite and do this on a cold start not warm. Solving Holley Sniper High Idle Issues - EFISystemPro.com 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? When I cover it with my hands, it gets quieter. your IAC is at zero. We will definitely be sticking with Holley from here on out for future retro-fits. 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. Am I missing something. 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! Fought a high idle issue until I changed your idle speed curve fix along with dropping the IAC hold to 10%. Or, at least, it should. 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. Does anyone have photos of this additional return spring they installed? Chris---I am contemplating replacing my Holley 750 on my new low vacuum 600 HP 496 with the Holley Sniper FI system. Part# 538-13. Nice to meet you. The Sniper ECU can use the timing to help maintain the idle speed and that will definitely be useful in that transition from Park/Neutral to Drive.If you don't have ECU-controlled timing, or if you do and it's not fully compensating, it may be necessary to increase your target idle slightly. Reducing that a bit will help. 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. The "Gauge Text" is what would be shown on a 2-1/16 gauge or the Avenger handheld display. However I do have a couple of issues I hope you can help me resolve. to. I recently had IAC issues identical to what you describe. Yes its at 95lbs, needless to say he promised a new regulator would be in the Good luck! Drop the IAC parked position a bit at each temperature point and sort of back into the solution. I also tried changing roc/map to 8 from 15 again no change at all.My ve table is smooth and tuned I even changed my AFR to 13.5 from 14.2 and no change at all. The learn function will offset the base fuel table until the closed-loop compensation only requires minimal changes. At some point you come upon problems that evade the easy answers and this is a good example. I drove it a bunch more yesterday afternoon/evening and the same thing happened several times. )Then look a the datalog and find out what TPS ROC and MAP ROC is most likely to cause the problem. Capability Range: Professional 2. You can manually set it 57 after you run the Wizard if required. OK, I did the baseline idle speed screw setting. It won't take much! Simply use your handheld controller and go to the Tuning > Advanced > Advanced Idle > Idle Speed screen and click on the Idle Speed Curve function. 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. 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. MSD pro billet and 6AL box 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. With select intake manifolds, the distributor housing and IAC valve on the back of the Sniper EFI throttle body are fighting for the same . No, the idle speed curve setting isn't something that you normally worry about--and especially not down at minus 40 degrees farenheit. We are running a Sniper on my mates 355ci small block V8 & so far he is very impressed ! 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%. I've made all the adjustments, all the settings, and the IAC issue is driving me crazy. You advise would be greatly appreciated. The Sniper EFI remote IAC (Idle Air Control) and plug is designed to gain installation clearance on some Sniper EFI 2x4 installations. :-). When the lambda is 1.0, the displayed AFR is 14.7;1 REGARDLESS OF THE FUEL. One way is to very carefully watch the handheld monitor, and that may be adequate. knowledge with the sniper efi setup. For the first couple of drives it was running well, Sniper EFI was working exactly as advertised. idle counts from 0. Going in the direction you did (higher) is going to reduce the acceleration fueling that the engine sees. To get it to idle the tps is at 2-3-4% even with linkage disconnected and a return spring installed. Note: The IAC breather hole is the roughly 1/4-inch triangular hole that sits above and between the secondaries. By going into the IAC settings and turning off the Idle Spark control and setting Target Idle to 750 RPM my idle issues are gone, and it now returns to desired idle after cruise. )Take a look at your AFR during the starting process. Using a Snap-on variable timing light so this is why I say timing is perfect. A good example of why it's so important to run a good pre filter in the fuel line. So if you are trying to achieve a stoichiometric mixture in ethanol (which is achieved at an AFR of 9.0:1) then you should continue to target 14.7:1 since that is what will be displayed. If this is the case then some adjustment of the linkage or the butterfly plates themselves is necessary. It does this with the engine off. 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). And, hopefully, within those degrees you will find a place where you don't get the whistle. Now it registers zero and I have good idle but it will not register until it hits 60 and up. The Sniper EFI replacement throttle body for Autolite 1100 carburetors will be right at home on most early in-line 6 cylinder powered grocery getters or weekend cruisers. I figured out I was going the wrong direction when I was messing with the AFR programming. If the issue persists, you may need to replace the IAC. One of them might be faulty. holley efi. 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. I do know that the reference angle is 57.5, the inductive delay says 100.0. I have turned ignition off turned screw in 2 turns and turned ignition back on and tps is at 1-2% not sure whats going on. Simply go to those cells, tweak them up or down as required, and the ECU should now be able to learn its way around the bog. Did you find this enlightening? Take a drive and stop somewhere for 30 minutes, CTS is 170 when engine was shutoff. Stupid question, but where do I see if it's entering Learn mode? This page was generated at 12:25 AM. But nothing beats a good solid gut-check Turning off and then on again, the engine returns to normal. If it is already adding fuel, it may be worth expanding this into the area where the tip-in is occuring (and where there is no learning occuring. Seems to behave more better now. No big deal, just time to re-adjust! So I had my Idle set up perfect, with idle timing control off and engine hot the IAC was right at 2-4%. If I read it correctly, the solution from the other thread seemed to fix a constant 300 or so RPM increase. Sniper EFI Tuning & Tech. 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. Price Point: $$$. You want to ensure that nothing is hung up in there.The only thing that I can think of that would cause the fuel pressure to spike when the motor starts is the increased fuel flow at the higher alternator voltage (jumping from 12.0 to 13.5 volts or so.) I'm thinking it could be the fuel pressure--- since I have a new Spectra EFI tank and there's been some reports of the interior coating coming off and gumming up the pump however the sniper display DOES NOT show fuel pressure.the Sniper DOES measure fuel pressure on its own - i've confirmed that with holley techs as they told me to purchase the fuel pressure gauge that can just hook up to the 1 wire gauge harness from the Sniper. 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. Running the vacuum advance and of course I time it disconnected. 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. Shut off car/restart and it's back to idle at Ive played with the timing on this thing multiple times.Car was fullly restored last year. In fact, it is those users who seem to end up most impressed with the system. 34K views 1 year ago Holley Sniper How to Set The IAC Idle air Control in 5 minutes or less. If more info is needed just ask. That is not the way to go. A problem since day 1 - YouTube Leave a comment if you've had this issue and how you resolved. you have it set. 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. Give us a hand! Confirm the placement of all wiring, ensure that the WBO2 sensor is positioned properly, etc. Hi Chris , greetings from Down Under (AUS) Just a note on the hi fuel pressure issue . With everything else being right and since you can make it start by adding fuel it seems like you must have some sort of fuel pressure issue. Good luck! That will at least tell you something. I keep doing that with the same result. Robust, feature-rich multi-port EFI systems offer easy plug-and-play late-model V8 engine swaps. 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. 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. Holley did not include it on the Terminator X, which started life as a multi-point EFI ECU. Sniper EFI Problems - Holley Performance Products Forums 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. It's all part of the pleasure of EFI. the gas it catches itself and runs fine at slower speeds. 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! Getting the throttle blades and IAC to work together will keep your fuel injected hot rod running smooth and predictable. 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. Using the handheld, navigate to Tuning > Basic > Basic Idle and ensure your target idle speed is set to the RPM you desire. Shut off the engine, ensure power to the Sniper is switched off. Featured Products EFI - Fuel Injection $2.59 - $6,499.95 2179 Products View Parts Sensors *Possible delays due to Covid-19 click for more information. The data that you provide shows that you have at least two problems. Let When I put it in park the idle RPM was 2100-2200 each time. EFI Troubleshooting EFIand and EFI Tuning Tips - In The Garage Media Ive had an idle at neutral as high as 2400 rpm. Yes, it will talk to you--but not with words. 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. That's a nice change of pace--a low idle issue! Idle when warm was 850-ish and IAC 3-4 just as when I readjusted it the night before. It sounds a little different from mine, since it commands a 1300 or so increase intermittently. 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. Thanks for the great question! I would gladly engage with you to solve this but ultimately you are going to need to go through whomever you purchased the system if a warranty return is in order. Holley Sniper IAC Problem - Holley Performance Products Forums Kind of cuts into forum time. It felt like it was flooding out at low speed, low. It is temperature dependent but 30 is commonly where you find it. And your understanding of how the throttle position affects idle is exactly correct. I think that your Sniper system is working fine but would definitely check ouf the fuel pump. Holley EFI Electronic Fuel Pressure GaugeI think its a little ridiculous that I cant see fuel pressure on the display even though its measuring it but whatever. issue. These are "transitional" cells, and you really have to make the effort to learn in these areas of the map. Do please let us know what you find out! Thanks for all your help Chris! But after sitting static idling for a little bit, the IAC goes to 100% & stays there. You might have a bad IAC, but you can also have a bad vacuum pod on the transmission. Wish I had bought my sniper from you, but unfortunately didnt. IAC Calibration / Hanging rpms | Team Chevelle A couple of those and you should feel it getting better. it will jerk and rpm will go up and down and AFR will be around 20 : 1 or more or less. Its just at low speeds, not sure if its loading up or leaning out. This page was generated at 12:26 AM. It could be a couple of things. 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. There's a procedure there I can share with you if you'd like.. Another suggestion is to add an extra turn to the spring built into the linkage to increase the closing force on the throttle shaft. This is extremely unreliable afrer warm. idles good, runs amazing. No timing control, coil negative ignition type. Drive great and idles perfect at stop signs. First, recognize that the amount below your target where you set the hard idle will be different on different engines. It's hard to know what the previous owner did right versus wrong. My Sniper started having a ticking noise-- I have 90 miles on my Sniper, but this started the last 10 miles or so: it still drives fine, but it worries me so i've stopped driving it for now. Ensure all your sensors are displaying proper values. 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. Take it a step at a time. I recommend you have a look:https://www.efisystempro.com/efi-pro-hangout/holley-sniper-efi-instruction/solving-sniper-rfi-problems, I recently purchased your fixed linkage to open primaries first and the throttle linkage extender to also get a smoother pedal. I also raised idle at Park a bit with the idle screw. If you go the other way then you might find that the IAC zero's out when the fans are off. I' m going to put the 3 rd new pump this coming friday. I am Japanese who attached Sniper EFI. After pumping the pedal a few times at different times it dropped to zero and started to work. Have you checked your fuel filter and made sure it's not plugged?If both of these are okay you're going to have to find a way to monitor your fuel pressure while under load. If that tested out okay then I can really guess that there might be some sort of intermittent, temporary RFI. The fuel pressure regulator in the Sniper is fairly simple and not prone to failure, as far as I know. If you complete the process and find that the IAC is less than 2% at idle, repeat the process and use the set screw to make the RPM about 60 RPM below the target. I, too, wish you'd bought your Sniper from us! The Tech Tips and discussions are also great! Hopefully replacing the pump again will resolve both issues. If the engine idles at 750 RPM with the throttle plates all the way closed and the IAC at zero then there is some sort of an issue. I will turn it up some more.Is this something that the ECU will learn? But there are several degrees of play there in which it should still work fine. In some cases, you may only be able to put as little as 10 RPM between the hard idle and the target idle. Start by doing the fastest start you can that doesn't bog. 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. shut truck off. Earl's Mechanical Fuel Pressure GaugeI could use that for a quick troubleshooting for 1/3rd the cost of the Holley one. Ran 2 Holley carbs and an Edelbrock. The last pic is with the car in Drive. Not that I noticed. Cl. But after sitting static idling for a little bit, the IAC goes to 100% & stays there. When I drive with warm engine the IAC is at 30% when pushing gas, but shouldn't it be at 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. Should I just disable idle timing control? Definitely not 90. Ive tried setting the prime setting above 150 but it wont take, it always goes back to 150. :-). Is this normal ? I hold my foot steady in place it does this in 5 second cycles and if i let go of I'm Having trouble with the Sniper on high 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. You'll have to go back and forth a couple of times to get it just right. Closed Loop Compensation rises to 100%, Do I just keep pushing it the same way to 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. If it is not a problem with the Sniper EFI System itself then it could be an issue with some sort of harmonic involving the fuel pump. It sounds like you need a bit more of a fuel squirt on acceleration, Brett. Explained: Holley EFI Sensors and What They Do I called support line he said he would have to look into it and call back. 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. Which means you either need to increase that number or increase the ramp decay time. Its on a big block Mopar with stock electronic ignition . It's going to be really difficult to nail down the problem with the several simultaneous changes that you've made. All times are GMT-6. Relatively new Sniper EFI install on a '69 Mustang 302. I followed the instructions and set the IAC to 2-9% when warm with idle at 850 RPM. 680-700.I can't find any reason other than it looses where it is in the firmware with 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. Several good bits here. There's still a very small amount of airflow that squeezes past a closed IAC valve; it's that venturi like sound you're hearing. My primary reason for going EFI was drive-ability, (Startup and take off without waiting for the engine to warm up) and not have the occasional hesitation a carburetor has especially just barely opening the secondaries. I installed a Holley Sniper on my Ford Maverick 302 V8. Since it is unlikely that anything else changed it is most likely the IAC is problematic or the butterflies are not shut all the way. that my Air/Fuel ration was 15:1 and I believe the target is 13.5:1. Once you confirm the operation of your IAC then it's time to read my article on Solving RFI Problems. Your closed loop compensation is adding a full 50% fuel. My IAC and TPS show zero when it does this. It wont fire up. Now it's at 5% on a big cam 440 Mopar. But I think it is safe to say that you are now at a point were some manual tuning is a good idea. RPM = 1200My slow gear I leave with 650 RPM, the IAC Position I leave between 5 and 6%, the All EFI systems need a large fuel filter to trap dirt and yet not reduce volume. check, I guess after reading everyone saying how great the system is after If idle drops below 800 it wont come back itll chug around 300 rpm for a few seconds then die. You might even want to add our 4-foot extension harness that will allow you to connect/disconnect the display or CAN-to-USB adapter from inside the car (rather than trying to do that leaning over the engine and under the breather. One thing you need to sync the timing and set the inductive delay. I was 20 minutes into a drive yesterday when all of the sudden the RPM increased not commanded. And if you're going to go this route I'd recommend that you switch from "Simple" (3 A/F targets, one each for Idle, Cruise, and WOT) and go to the 2-D Table Your AFR is pegged lean. So, this is what it takes to put a Sniper on a small-block Ford.