Um, no. First, check to make sure that the IAC is properly mounted and connected. Have a look--I think this is going to allow you to fix your idle problem. The weather in Ct has finally improved and I have put about 60 miles on the car with the Sniper system. The hold position is part of the response that keeps the car from dying when you come off the throttle. Possibly cap, rotor, coil? Just getting it to act right at startup is a struggle. 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. SNIPER EFI TO HOLLEY DUAL SYNC HARNESS Part# 558-493 $34.44 Qty: Add To Cart Idle Air Control Motor Replacement Idle Air Control (IAC) Motor for Sniper EFI TBI Systems, Sniper 90/92/102mm Throttle Bodies, Terminator TBI, Avenger 4bbl TBI, HP 4bbl TBI, Commander 950 & Digital Pro-Jection Systems Part# 543-105 $71.72 Qty: Add To Cart Going lower with the blanking might pay dividends, but there is so little room below 7/8 that you will quickly be in a range where every tiny variation in the TPS or MAP is throwing extra fuel into the engine. Sniper EFI - Holley I believe that you have this problem solved now with your new inline filter/regulator. MSD pro billet and 6AL box Hello Chris. In the Wizard, select the stock cam setting. Yes its at 95lbs, needless to say he promised a new regulator would be in the Should the iac% fluctuate? Otherwise, if removing the air cleaner eliminates the whistle then try to use a thicker gasket or try lightly greasing the gasket. We are running a Sniper on my mates 355ci small block V8 & so far he is very impressed ! >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. Was perfect idle iac reading 3. The IAC reads 36 when at idle fully warmed up. How can I adjust the startup speed down to about 1400 RPM? But I am having troubles.When stepping on the accelerator slightly with idling, it will be 2000 RPM all the time. Hello Chris. 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. Your suggestion to remove the PCV valve is just for diagnosis purposes, right? This software is going to allow you to open both the configuration file and the datalogs that you create, overlay them and you can get a much better idea of what is happening. A problem since day 1 - YouTube Leave a comment if you've had this issue and how you resolved. I've been trying to correct that 1% small issue/annoyance. I'm happy to walk you through what is required. Or alternator? Then your low idle problem will go away. The IAC should display a 2-8% to bring the idle up to the actual target. One additional wrap on the secondary coiled shaft spring is all that's necessary. Commanding the engine to automatically increase speed when switching into drive is a little scary to me though. 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. 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. Ok, so there are a couple peculiar things going on here. Bryan McTaggart 02/28/2023 news I'm running a 408 sbc. Fuel Prime Multiplier is primarily a benefit to throttle-body based EFI systems. Setup: 1965 Impala SS; ZZ6 Crate Engine, EFI Distributor. The throttle blade adjustment is at 2-6% at hot idle, and with warm engine 185F. This minimizes installation time and packages really well on a diverse group of engine applications. 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. If they are closed, check the primaries. It starts cold fine, its just when its hot. The fact that it ran so (at times) with 90+ PSI fuel pressure is a testimony to the Holley's closed-loop technology. Ok, we have enough Sniper systems out there that I thought it would be a good idea to create a posting on challenges that might arise during installation. Comp. After pumping the pedal a few times at different times it dropped to zero and started to work. Bolt-on carburetor style EFI for your classic car or truck. I was looking at a data log from my truck earlier this week and noted that at idle my IAC was zero. If you haven't confirmed that they it is worth checking. Thanks for all your help Chris! Don't try to correct for the fuel. 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. At some point you come upon problems that evade the easy answers and this is a good example. Between the kick down and the return springs on the throttle body the pedal is so hard to push it's pretty much a jack rabbit start every time from stop, it's almost undrivable, any suggestions on what I could do?thanks for help, I've tried both Holley's tech lines for close to 2 hours with no answer! 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. 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. 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. 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. Doesn't want to start, runs like crap. I have not heard of this. What could be the cause? That is the default "Clear Flood" TPS setting and turns all fuel off until the engine cranks. )Take a look at your AFR during the starting process. Initial Baseline Idle Speed Screw Setting, http://forums.holley.com/showthread.neral-IAC-Info, http://documents.holley.com/199r11031r.pdf, https://forums.holley.com/showthread-Idle-Solution, If this is your first visit, be sure to Take it a step at a time. Which means you either need to increase that number or increase the ramp decay time. is jumping all over the place when you experience this condition, it does not If you go the other way then you might find that the IAC zero's out when the fans are off. 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. About two minutes after I get it set at 850 & 5%, it has progressed to 100%. This may require shortening or lengthening a rod. Yes, having an accurate TPS is very important at idle. 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. And the only way to be positive about that is with a gauge.Unfortunately, the Sniper does not provide an input for an electronic sender so the next best thing is an analog gauge. Target AFR, A / F = 13.5 IAC looks good once it finally s fires. 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. In this short video you learn to replace the IAC. Bolt-on carburetor style EFI for your classic car or truck. Does anyone have photos of this additional return spring they installed? Hey Chris! Tried that and it didn't work? Only in the unlikely event that your engine simply won't run well enough to drive and self-learn should you consider tweaking anything inside of the first several hundred miles. You've got it running and warmed up but now you need to set. Be aware that there is a spring behind there and a diaphragm that you don't want to tear. My guess is a faulty IAC since it is intermittent and I have not done any setup changes. Should it not do the opposite and do this on a cold start not warm. Holley - 543-105 EFI Idle Air Control Motor , Black - amazon.com It only lowers to 2-6% when I take my foot off the gas. it will jerk and rpm will go up and down and AFR will be around 20 : 1 or more or less. When I shut it off then start it Use the idle speed screw to set the idle at a comfortable warm-up speed. You mentioned going from 13.5 to 14.2 but you'd want to go in the other direction--maybe to 13.2. Sniper EFI Idle Tuning - Holley Motor Life )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). Is there any chance that your timing has changed since you installed your Sniper? Next, clean the IAC and all related parts with brake cleaner. When I put it in gear, it drops so low that it will stall if I don't add throttle. So I have been doing the slow take offs and thinking that it would learn its way out. Interesting question. An undersized or partially plugged fuel filter is a classic EFI installation mistake. I would suspect something is coming loose causing a stop to the EFI system/Fuel flow. The team at EFI pro are some of the best I have ever dealt with when coming to ordering parts or having the knowledge to answer any question you may have. I received from the controller manufacturer greatly understates (at best) the repeated failures of others I know personally who have tried and failed. After the start process, If the idle speed is higher than the target idle then the IAC should begin closing as long as the TPS is below 2%. What might cause the TPS to go to 2%? In the setup, I set the hot idle for 850. You might have a bad O2 sensor, really bad exhaust leak or a problem with the ECU. So glad this was helpful. 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. You advise would be greatly appreciated. But after sitting static idling for a little bit, the IAC goes to 100% & stays there. Im thinking a faulty TPS. I think that your timing is too retarded. No matter what do, my idle will not drop below 1350-1400 RPM when the engine warms. Even at 0% it's sucking a bunch of air through the IAC port. If you have any questions about the car/setup let me know. These problems will go away when you do that. Note too that the larger the throttle stab, the more brief the time in that cell and the more gradual the change.Here's what I recommend: Get somewhere where you can repeatedly stop and go. However I do have a couple of issues I hope you can help me resolve. I' m going to put the 3rd new pump this coming friday. A good example of why it's so important to run a good pre filter in the fuel line. Short drives is fine then it'll Jun 12, 2021. It then started working normally again. Hi I wish I had bought from you but I didn't find this site until now. I have checked the pink wire and it is at .001 volts when key is off. 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. Without it you are working in the dark. Holley Sniper How To Set The IAC (Idle Air Control) in 5 - YouTube Now that you've installed at least four Snipers it is going to be imperative that you learn to create and read datalogs. Hi Chris thanks in advance for any tips. If I go any more it will ping. I watched the butterflies start to open at about 35 on TPS. How to replace the IAC in the Holley Super Sniper. - YouTube However, I did have another fellow who contacted me that claims he went through three units before he could get one that would talk between the ECU and the Monitor. ps. The Sniper Quick-Start Manual provides the following instructions for setting the idle. 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. But I think it is safe to say that you are now at a point were some manual tuning is a good idea. But after sitting static idling for a little bit, the IAC goes to 100% & stays there. Thanks so much for reading! After doing TPS reset it starts fine but when you give it some gas it hangs at 1500 and will not return to idle. If the TPS is 1% or below then the air is coming from somewhere else. If so remove it. This is normally used as an A/C idle-up circuit. The tps will not auto reset to zero. This will tell us if the ECU thinks that it is in control of setting the idle or if it thinks that you are driving the engine speed with the pedal. Repeat until that stumble goes away, and then try a bit more throttle. If this is the case then some adjustment of the linkage or the butterfly plates themselves is necessary. Copyright 2022 Holley Performance Products, Inc. All right reserved. I'll have to check again tomorrow. Thank you very much. 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%. And increasing your idle via the idle screw was also a good idea, because that will lower your amount of IAC that is necessary to keep your engine at the target idle speed. Definitely not 90. Holley sniper, bogging/ losing power "NOW FIXED" The fuel pump is mounted under rocker panel as low as possible and far away from any heat. shut truck off. 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. Sniper EFI Problems - Holley Performance Products Forums It runs perfectly fine other wise. (Plus they it just looks way cool in your engine compartment!) When this happens, it is impossible to convince the Sniper ECU to allow the RPM to drop below a set RPM--regardless of what the target idle speed setting is. Start engine let it warm up to 160, learn mode is learning. 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. Sniper EFI Tuning & Tech. Camshaft is M-6250-B303 .480 lift intake & exhaust, duration at .050 is 224 degrees for intake & exhaust. You can disable the idle spark control at the locations below. !I called Holley today, and before I could even described the symptoms the Chris, I recently installed my Sniper and have an intermittent idle problem. You can drop it down and you will find it will behave more like you expect. Okay, try my method. If your TPS has snuck up to 2% then your IAC will be at the hold position, which by default is 30%. Holley will take a look and tell you you have RFI and wish you good luck in finding it. In the datalog the engine is running at 1400 RPM, TPS is zero, IAC is zero, CTS is 185F but it's in Open Loop. I do know that the reference angle is 57.5, the inductive delay says 100.0. IAC Calibration / Hanging rpms | Team Chevelle Some have suggested the gasket might cause it but I've never heard of anyone fixing the whistle by adjusting the gasket (and many have tried. EFI parts, including the throttle body, and the problem persists.Please give me a hand. Hello 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! Sorry for all the questions, new to the efi world. This will let you know at a glance if something is going awry with the fuel pump. Idle quality is great, RPM is good, sometimes IAC is now between 2 and 5 exactly where it should be. IAC is good 0-5% most of the time. I set the AFR at 13.5 and all is good now. What should I be looking at to calm this down? At low levels RF interference will often reset the ECU so quickly that the engine will not stall. I have adjusted many settings and eventually mess it up and go back to the original map. 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? One thing you need to sync the timing and set the inductive delay. The biggest issue is these problems are intermittent meaning they do not occur all the time. technical rep said "You ahve high fuel pressure". Im in Australia, so stuck the sniper on a 355 Holden engine with CD box. The first place my eyes go when there is any issue with the idle is to the TPS value. Can the return line be an issue?I have had 2 faulty gpa-4 255 walbro pumps go bad. I'm also having a high idle problem but its different. Using the handheld, navigate to Tuning > Basic > Basic Idle and ensure your target idle speed is set to the RPM you desire. Car was running great initially. As I would slow down for a stop sign or stop light, the car would run really rough and the idle did not want to come down. Once you have done this the challenge is to create a datalog that includes the ":snap" you describe. There is no real mystery here. The RPM would increase for no reason. Capability Range: Advanced normal city driving, I no longer have other problems I had with the original (Grease can sometimes do the same thing as a more permanent gasket sealer without making the removal of the air cleaner such a pain.). If you use your handheld to go here: 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. I'm going to jump out on a limb here and say you either don't have adequate fuel flow or pressure. 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 Are these compatible enough? I have an entirely separate article on Solving RF Intereference Issues. The learn function will offset the base fuel table until the closed-loop compensation only requires minimal changes. One of the signs of a vehicle with a rough idle is a faulty Idle Air Control (IAC) Motor. Closed Loop Compensation rises to 100%, Do I just keep pushing it the same way to Then you can take a close look at the IAC and see if it is opening. Yes, the sound coming out of your Sniper throttle body is a pulsation from the fuel pump that is pulsing the mechanical fuel pressure regulator. I started with right after I first adjusted for 2% IAC and took pics about every 30 seconds over about 2 minutes. I can drive it a bit but pops through the throttle body when pulling out from a stop (4 speed) and sometimes in the exhaust out on the road. 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 think you'll be all set! 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. Even at 0% it's sucking a bunch of air through the IAC port. If the regulator is working correctly and there is no restriction in the return line that should make no difference however.Sorry I didn't see this on the Holley forum. It works instantly for him.If that fixes your problem then you have a starting place. After this whole process, the car normally rotates without a very abrupt pedal. That is the IAC hold position. The fuel pressure regulator in the Sniper is fairly simple and not prone to failure, as far as I know. Relatively new Sniper EFI install on a '69 Mustang 302. I did check for the lightning under the hood but all was well. I also noted that after some time, I could change those values as I saw fit. Solution #1 Put car in gear take off and the engine runs GREAT, no issues drive for 10minutes take car out of gear and engine idles correctly IAC between 2 and 5 Solution #2 Shutoff engine wait 30 seconds, turn key wait for display to come up, start engine. If 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. We are using Target AFR of 9.0: 1, Fuel Base approximately 40% higher. Any help would b great. But, if the idle is so high that it is making you crazy then you might try dropping that number just a bit. Im not sure what its doing, have messed with after start fuel, fuel at cranking. Target AFR at idle is 13.8%. Cl. Simply turn the idle speed screw on the linkage in until the throttle plates open enough for the idle to increase. 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. We've already tried adjusting the Acceleration Enrichment chart in all ways, going up and down, RoC Blanking, everything, it has no effect. My dad wanted to recheck the timing so I set the Static Timing at 15 and it runs perfect. Make sure that your blanking level is _below_ that (being careful not to find yourself in the situation I describe above.) Try it! So the issue Im having is low idle. Your comment doesn't imply any sort of problem that would make me give up on idle timing control. holley efi. Then a little faster--until bogs at that level work themselves out. back to trying to zero down an idle. 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). I keep wondering how it was running so good with Next, reach down into the secondaries and push the butterflies closed. He is able to get it to start by quickly depressing the accelerator to at least 60% and releasing. Mechanical Fuel Pressure Gauge on the inlet of your Sniper, now is the time. We will definitely be sticking with Holley from here on out for future retro-fits. I think that your Sniper system is working fine but would definitely check ouf the fuel pump. 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. Why is this? I've not heard of any others with this exact issue so I don't think it is a common problem. (It should be at or near 60 PSI at idle. Hi Chris I didn't get any traction on Holley.com It is working fine when you restart the car, controlling idle perfectly at 8 steps open so it is unlikely to fail when the car warms up--or correct itself instantly when you restart it..So, if you don't have any vacuum leak, and the throttle plates are fully closed, the only thing I can guess is something is causing your ignition timing to change. 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. Drop the IAC parked position a bit at each temperature point and sort of back into the solution. We're having trouble with a Ford Maverick 302 V8, using ethanol. Idle when warm was 850-ish and IAC 3-4 just as when I readjusted it the night before. I had that problem, right out of the box it would not power up, sent it back in, had defective hand held. I will try the other stuff when I get off work. My IAC and TPS show zero when it does this. 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.