If you set the RPM above idle to start ramp too high, then it may not ever get down to the RPM above idle to re-enable. For someone in your position, it will become an indispensable tool in your tool box. However, whenever you start changing things, you can get into a chain reaction. When the secondary throttle blades are centered in their bores and pivot freely, an additional return spring is not necessary. Next, clean the IAC and all related parts with brake cleaner. Fuel Flow lb / h = 12.1 I started with right after I first adjusted for 2% IAC and took pics about every 30 seconds over about 2 minutes. 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. Sorry for all the questions, new to the efi world. It will need to see it again and again. That, on top of your air leak, is allowing the engine to idle at 2400 RPM. That is the only way to fly. It may take a few tries. (It should be at or near 60 PSI at idle. The person I bought it from said he never could get it to run for more than a few seconds. There's nothing wrong with manual tuning, but at this point that is just compensating for an inadequate fuel map. I am Japanese who attached Sniper EFI. The noise changes sound with the throttle position. I know its not flooded because I can pour a little gas in the throttle body and play with the accelerator and it will start and run fine. Bolt-on carburetor style EFI for your classic car or truck. The first thing I'd do is check your fuel pressure with a gauge like this. 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 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. It shuts off when coming to a stop sign, at any cruising speed and romdomly at idle in park but never when excelerating. About two minutes after I get it set at 850 & 5%, it has progressed to 100%. Tuning > Advanced > Adv Idle > IAC Startup I did notice that when I thought I had it set An undersized or partially plugged fuel filter is a classic EFI installation mistake. If you have any questions about the car/setup let me know. idles good, runs amazing. Don't know if I should put this in a separate post. 680-700.I can't find any reason other than it looses where it is in the firmware with You could go either way.. If you use your handheld to go here: Overview. I am extremely suspect of what you were told about the Sniper ECU monitoring fuel pressure, for several reasons. Of the two options, I generally recommend the self-learn. nothing stays steady. Therefore The iac will always be at 10% now, correct? They are prone to be inaccurate. 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 I put it in gear, it drops so low that it will stall if I don't add throttle. Getting the throttle blades and IAC to work together will keep your fuel injected hot rod running smooth and predictable. check out the. 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. first attempt but as it tries to idle down to the target RPMsit can never even The fuel pressure regulator in the Sniper is fairly simple and not prone to failure, as far as I know. The throttle blade adjustment is at 2-6% at hot idle, and with warm engine 185F. Turn the idle speed screw on the primaries in about 2-3 turns after it makes contact with the linkage and starts opening the primary throttle blades. Then do it just a bit faster--just enough for it to bog a bit. Please let us know how this works out for you! Or is there something else I should I recently had IAC issues identical to what you describe. Holley Sniper Iac Delete It felt like it was flooding out at low speed, low. The first place my eyes go when there is any issue with the idle is to the TPS value. 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. The ticking is inline with the fuel pressure I feel squeezing both the fuel return & delivery lines (like a heartbeat). Hey Chris, I installed a Holley sniper on a small block 400, first start was great! Does anyone have photos of this additional return spring they installed? Well, it sounds to me like your Sniper is doing its best to reduce your idle. The fix? And, hopefully, within those degrees you will find a place where you don't get the whistle. To figure this out it's going to be important to gather a bit more data. Take it a step at a time. The broad consensus has been that the Sniper is an amazingly straight-forward install and starts and tunes as expected. (Plus they it just looks way cool in your engine compartment!) One of the great features of Holley's Sniper is the ability to set your air/fuel ratio (AFR) where you want it. Thanks again. One of them might be faulty. With the vehicle in neutral, adjust the idle screw until the IAC Position reads between 2 and 10%. Hello Chris. I'm new to the efi thing and any help would be seriously appreciated. Very annoying ended up being simple my rear plates would stay open constantly it was driving me nuts I'd let off the pedal idle at 1300 blip the throttle a few times finally come back to 850. 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. 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. New install, when in setup wizard TPS says 90 percent and I checked the linkage and butterflies. It's pretty hard to get the header tubes glowing at idle with a lean AFR. Definitely not 90. carburetor setup, but it does blow when I can't jump on the highway like I use 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. I have checked the pink wire and it is at .001 volts when key is off. I will let you know what the results are. You'll be amazed at how much of this just "goes away" when you drive it enough. Even at 0% it's sucking a bunch of air through the IAC port. If you go the other way then you might find that the IAC zero's out when the fans are off. Glad to hear that things are working well! 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. Check the Distributor Tach Connection to the EFI. That is the first thing you must find. holley efi. Changing the rpm curve and target rpm has no effect. 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. 34K views 1 year ago Holley Sniper How to Set The IAC Idle air Control in 5 minutes or less. Definitely would have went with you guys. Do you have a PCV on the engine? 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. I can adjust at 160deg, but my fans turn on at 180deg. I.e. Fortunately, Holley has another product that can solve that: Hydramat.. Hydramat is not inexpensive but you won't believe what it can do. Another suggestion is to add an extra turn to the spring built into the linkage to increase the closing force on the throttle shaft. When I removed the tape and started it again, it was idling at 1400-1500 RPM and sucking a bunch of air through the IAC, even though it showed 0% on the sensors screen (pic attached). Mechanical Fuel Pressure Gauge on the inlet of your Sniper, now is the time. Try it! 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%. Cycling the power to the Sniper EFI would cure the problem, but not prevent it from coming back. Coming home from work today it was much warmer and took a little longer due to traffic. Also, I was seriously rich at idleso rich it hurt your eyes. Your suggestion to remove the PCV valve is just for diagnosis purposes, right? If the TPS is 1% or below then the air is coming from somewhere else. 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 also raised idle at Park a bit with the idle screw. All times are GMT-6. The Street/Strip and race cam setups tend to be too rich initially. I would not expect that an electric fan would create a noticeable load on the engine but if it did then you'd want to set the idle screw when the fan was not running. I'm compltely stumped and my wife is certainly upset I'm spending so much time between the garage and the computer for something that should basically run out of the box. I keep doing that with the same result. I set the AFR at 13.5 and all is good now. any ideas? Hopefully replacing the pump again will resolve both issues. Chris, Both Sniper and trans controller grounds were direct to the battery ground, as they should be. The Sniper will be controlling the timing so it will be based on a multitude of factors. I am new to the EFI scene but want to learn. Hello, I am having a tps and idle issue. Super helpful and knowledgeable. I believe that for the HyperSpark the Reference Angle should be 57.5. In most cases the IAC (Idle Air Control) circuit is the source of the whistle. If you hit the gas it pops & backfires through the throttle body. 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 will turn it up some more.Is this something that the ECU will learn? 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. 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 When I shut it off then start it 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. There are six different acceleration enrichment tables that you can tweak and that may be the way to go. hard start about 1/2 throttle from stop it bogs down after 3 or 4 seconds.What I They tell you to ask call Holley. EFI Systems based on Holley's world-class Dominator and HP ECU's. I have tried your 10-step idle adjust and ive adjusted the idle curve. any advise would be appreciated. It sounds like you need a bit more of a fuel squirt on acceleration, Brett. Hi Chris thanks in advance for any tips. Thanks for the great question! To get it to idle the tps is at 2-3-4% even with linkage disconnected and a return spring installed. In the Wizard, select the stock cam setting. :-) Just don't let the parts go flying. Even though the Sniper's fuel map is programmed to provide the correct amount of fuel via injectors spraying at 60 PSI, if the pressure is jacked up to 90 PSI the wideband sees that you are rich and faster than you can even detect it audibly lowers the duty cycle to inject the correct amount of fuel. If not then you have some other issue that is behind this increased idle. Was perfect idle iac reading 3. I think in some of the Wizards with the handheld it doesn't use 57.5 as the default. Holley Sniper IAC Problem 04-26-2018, 11:30 AM Hello. It's all part of the adventure! 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. Copyright 2017 Cyberspace Automotive Performance, Inc. All Rights Reserved. I will try the other stuff when I get off work. I' m going to put the 3rd new pump this coming friday. Its rare that you find someone that genuinely wants to help and see something work good, the information I have received from this page and Chris himself is top notch.1969 Dart GT 340 with a Holley Sniper, I purchased the Holley sniper from jegs wish I knew you sold them put on my truck got the IAC set haven't checked the -40 idle setting yet my problem is my headers are glowing red called Holley I think I got the worst person seemed to care less Afr is set at 12.8 for idle only thing I have changed I don't smell any fumes at idle someone said I could change the coolant temp enrichment but I don't know if it is rich or lean I figured since no smell it is lean any ideas would be appreciated thanks i have a fuel psi gauge reads 60 psi don't wanna melt my motor did not glow with a carburetor. If this is the case then some adjustment of the linkage or the butterfly plates themselves is necessary. Camshaft is M-6250-B303 .480 lift intake & exhaust, duration at .050 is 224 degrees for intake & exhaust. As you have noted, each time the idle goes up. What might cause the TPS to go to 2%? 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'll have to check again tomorrow. All EFI systems need a large fuel filter to trap dirt and yet not reduce volume. But I think it is safe to say that you are now at a point were some manual tuning is a good idea. Hey Chris! The IAC reads 36 when at idle fully warmed up. If you don't have a working coolant temperature sensor then it will never bring the idle speed down. When running it will only stay in closed loop and learn at idle. If you did not rotate the distributor to set the actual timing to 15 that might be the only issue. It is how the engineers allow you to clear a flood condition when you detect it. We have never had that problem with any of the units that we have shipped. Are these compatible enough? The fuel pump is mounted under rocker panel as low as possible and far away from any heat. It'll start & run till it's warm, then when I try setting the IAC every time, I try getting it between the 2 & 8% it quits. I never had a problem with this. Take a drive and stop somewhere for 30 minutes, CTS is 170 when engine was shutoff. 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. Yes, let me know how that setup process works. It works instantly for him.If that fixes your problem then you have a starting place. The tps has slotted holes, can you adjust it to get to zero? Your mechanical advance will naturally change the timing a bit but it should be fairly close. TPS% = 1 Initial thought is timing but Im running a cd box and the ecu is not controlling and I did not physically change it during the install. What could be the cause? Kind of cuts into forum time. Even at 0% it's sucking a bunch of air through the IAC port. To start viewing messages, select the forum that you want to visit from the selection below. The warmer the motor, the higher the idle will be at this point. Fortunately, I have an article that goes into this in some detail. 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. 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. However based on your reply I connected the Fuel Pressure gauge and Its just at low speeds, not sure if its loading up or leaning out. The team at Holley has designed the perfect solution for your problems. It does this with the engine off. I've made all the adjustments, all the settings, and the IAC issue is driving me crazy.