holley sniper efi iac problems holley sniper efi iac problems

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. I keep doing that with the same result. All times are GMT-6. My IAC was constantly at 100% at idle. Tried that and it didn't work? One way is to very carefully watch the handheld monitor, and that may be adequate. 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%. If I put the vehicle in gear the idle gets higher with temp. But they are 100% committed to your satisfaction. I think that this time around you will find that it starts and idles really well and only gets better from there. The noise changes sound with the throttle position. 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. 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. The only way to do this is by installing a mechanical fuel pressure gauge. They also worked with me on a sale I missed and price matched those parts. And the rather cavalier "Absolutely!" 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. In addition to avoiding this particular problem, the total solution is much better. The throttle blade adjustment is at 2-6% at hot idle, and with warm engine 185F. 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. MSD pro billet and 6AL box One of the great features of Holley's Sniper is the ability to set your air/fuel ratio (AFR) where you want it. I can have it working fine (5% to 10% at target idle at operating temp.) After 50 on the throttle position I'm not sure if the whistle goes away or you just can't here it anymore. The next time it happens is the perfect opportunity to find the problem. We've already tried adjusting the Acceleration Enrichment chart in all ways, going up and down, RoC Blanking, everything, it has no effect. Thank you so much for your follow-up. Wish I had bought my sniper from you, but unfortunately didnt. You have to remove all hoses in order to debug the problem. Could be a bad IAC motor, replace it and see if that solves the problem. holley efi. TP range is normal goes up to about 90% with throttle pedal to the floor. 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. But if you can datalog the bog you can know much more precisely what is happening. If you remove the air cleaner entirely and the whistle continues then you can rule that out. I appreciate everything you are saying. Also when ac kicks on it will idle down and stall. All times are GMT-6. Now it's at 5% on a big cam 440 Mopar. You're going to have to get this fixed or it's going to cause even more problems than the high idle. Capability Range: Moderate We're never going to fill up your email box with nonsense. I readjusted my IAC, now it's perfect. I did read some comments on regulator issues is there a way to check it for an issue ? The problem I experience is that after driving for about 10-15 minutes, the car starts idle to high. If this is the case then some adjustment of the linkage or the butterfly plates themselves is necessary. Put a strong piece of tape over the IAC breather hole--duct tape or something that couldn't possibly be sucked into the throttle body. Then Friday night as I was driving home, the car started acting up. But when you have it then you can look for exactly what the IAC is doing at that point, and if there is anything that might lead to this happening. At low levels RF interference will often reset the ECU so quickly that the engine will not stall. A question I cannot get a 100% answer on is can you piggy back off the Sniper EFI TPS for an electronic transmission? Seems like its too slow to grab idle when ac kicks on. Definitely not 90. The hold position is part of the response that keeps the car from dying when you come off the throttle. Hello I'm running a 408 sbc. Try it! Fortunately, I have an article that goes into this in some detail. By the way, this is a new installation on a 69 Camaro, stock 350, dual sync, etc. It would be possible to set up a 1D or 2D table and do something like this, so if you've gotten into these advanced setups then that would be another thing to check.If neither of these work then I'd recommend that you do a data log of the engine idling as the temperature is reaching and then exceeding 200 degrees. Somehow air is entering the engine that was not entering the engine when you originally set the idle speed screw. We're having trouble with a Ford Maverick 302 V8, using ethanol. It is temperature dependent but 30 is commonly where you find it. That 34K views 1 year ago Holley Sniper How to Set The IAC Idle air Control in 5 minutes or less. I am at the point where I almost insist that every Sniper EFI System owner purchase one of these. I'm wonder if the iac can cause this. Thank you. 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!) Hello. It is how the engineers allow you to clear a flood condition when you detect it. Now, in my lifetime of experience with Holley ECU's that seems unlikely, but this guy sounded really sharp and had nothing to gain by convincing me of his dilemma. 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. I'd really appreciate some help. Going back to what you said. 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. When you open your IAC to 30% you are naturally going to have a high idle condition. But before you adjust the ECU to lean the idle out, first confirm that your fuel pressure is right. 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. Perfectif you have the original synchronous linkage. However I do have a couple of issues I hope you can help me resolve. When I turn it off and try to restart it just cranks. When I covered the IAC with my finger, the RPM dropped so low it stalled. Give us a hand! You can find those settings here: Handheld: Tuning > Advanced > Advanced Idle > Rampdown, Software: Idle > IAC Settings > IAC Ramp Down. Check the Distributor Tach Connection to the EFI. This can cause the engine to run rough and may even lead to engine damage. Engine has never stalled with Sniper system, once placed in Drive it just goes!!! After this whole process, the car normally rotates without a very abrupt pedal. 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. This curve turns the idle speed down as the engine warms. Your comment doesn't imply any sort of problem that would make me give up on idle timing control. ?I never had my Carb Cold start RPM any higher then 1600 RPM.THANK YOU. The "Gauge Text" is what would be shown on a 2-1/16 gauge or the Avenger handheld display. If you go too low then it may stumble or even stall when coming off of throttle. Again, I would lean on that solution to let the vehicle drive/learn before you try to "fix" anything. *Possible delays due to Covid-19 click for more information. I did check for the lightning under the hood but all was well. Copyright 2022 Holley Performance Products, Inc. All right reserved. Sorta similar to a carb having the idle mixture set incorrectly (rich) or the idle speed too low. It appears that I could now use the dongle and a laptop to custom tune for idle issues if needed. Short drives is fine then it'll 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. I've not heard of any others with this exact issue so I don't think it is a common problem. Interesting question. Software: Idle > IAC Settings > Idle Spark, Handheld: Tuning > Advanced > Advanced Idle > Idle Spark, After completing this 10-step process, if the temperature displayed on the handheld is still above 160 degrees the engine should go right to it's target. If the screen shows iac at 0 and you block the hole to find it open what does that mean? Be aware that there is a spring behind there and a diaphragm that you don't want to tear. No matter what do, my idle will not drop below 1350-1400 RPM when the engine warms. I'm Having trouble with the Sniper on high Idle. Idle when warm was 850-ish and IAC 3-4 just as when I readjusted it the night before. 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. Going in the direction you did (higher) is going to reduce the acceleration fueling that the engine sees. I did buy the Sniper from you guys and the service was fantastic. I went on the good ole interweb and found your website which was VERY helpful! 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! Even though you think your timing is perfect I'd suggest you try cranking about 5-10 degrees of advance into the distributor and just see if that doesn't work better for you.Remember this: adjustable timing pointers go out of adjustment and harmonic balancers slip. Is there away to program the ecu to compensate for this at start up. Could you provide me with some things to check or some things to adjust? So try changing your IAC hold value slightly:Tuning : Advanced : Adv. If you find that adding 5-10 degrees of advance helps then it's time to do reconfirm TDC. Second--even in the HP and Dominator systems where a fuel pressure sensor can be dalogged and displayed, the fuel pressure is not fed back into the algorithm. There is a chance that the IAC is open but displaying 0% so start by putting your finger over the IAC opening. Copyright 2022 Holley Performance Products, Inc. All right reserved. The first thing I'd do is check your fuel pressure with a gauge like this. Then follow all of the instructions above, including confirming the idle speed curve setting at -40 degress as well as following my 10-step process for setting the idle. >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. carburetor setup, but it does blow when I can't jump on the highway like I use You can disable the idle spark control at the locations below. 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. That will at least tell you something. When I am coming to a stop, the rpms will hang at 1200-1500 rpms. Those don't impact the way the engine runs and can cause the whistle sound you describe. 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? When I covered the IAC with my finger, the RPM dropped so low it stalled. I was looking at a data log from my truck earlier this week and noted that at idle my IAC was zero. 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. If the TPS reading on your Sniper EFI System does not reset to zero that is a problem that needs to be addressed. Last night I tried setting the IAC and had the same problems after it's warmed up. The data that you provide shows that you have at least two problems. The problem was RF interferance . 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. Sniper EFI offers superior throttle response and wide-open throttle power. Supports up to 650hp with Four 100 Lb/Hr Injectors! Turning it off and back on would reset it, and then it would work as advertised for a while. I presume your idle speed table doesn't increase at 200 degrees? In some cases, you may only be able to put as little as 10 RPM between the hard idle and the target idle. They also recommended that their ground be spliced into the Sniper ground as close to the Sniper as possible. I never had a problem with this. Cracked casing from a side cover screw being installed crossed threaded. Car was running great initially. 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. This page was generated at 12:25 AM. As far as the timing light, I don't know, because I was having problems getting it to work, and that's where I stopped. That is what I really respect about Holley. Holley documentation and videos didn't work and the $300 I paid for "expert" tuning didn't work either. 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. An under-sized filter will allow part- throttle operation but fuel pressure will drop at WOT and run very lean - perhaps surge under power. What can I do? If I read it correctly, the solution from the other thread seemed to fix a constant 300 or so RPM increase. 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. But get that fuel system fixed before going any further. Both Sniper and trans controller grounds were direct to the battery ground, as they should be. 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. 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. Two things to keep in mind as you do that. Repeat until that stumble goes away, and then try a bit more throttle. Ilike a few othersam having idle issues. Except at idle. 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. issue. I installed another return spring for the rear plates problem solved instantly. I'm new to EFI and have no idea what to try next. You've got it running and warmed up but now you need to set. When I put it in park the idle RPM was 2100-2200 each time. Installed sniper on 65 galaxie. 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. 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! The Sniper EFI system looks at the closed-loop fuel compensation required to reach your target AFR. The fuel pump is mounted under rocker panel as low as possible and far away from any heat. 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. You might have a bad O2 sensor, really bad exhaust leak or a problem with the ECU. Also, I was seriously rich at idleso rich it hurt your eyes. If your TPS has snuck up to 2% then your IAC will be at the hold position, which by default is 30%. First, I'm kind of insistent about not changing any of the default settings unless the vehicle absolutely will not cooperate enough to drive/learn, and only then if you have a specific understanding of the problem and a specific solution. I have driven car about 200 miles. For someone in your position, it will become an indispensable tool in your tool box. mean that the IAC is causing it. Of the two options, I generally recommend the self-learn. Bryan McTaggart 02/28/2023 news :-). You will have to do this until the TPS stays at 0% when the throttle is closed. It only lowers to 2-6% when I take my foot off the gas. Kind of cuts into forum time. The throttle position should be zero. Given the circumstances I would say that it is either the IAC motor itself or RFI but you seem to have ruled both of those out. 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 It runs perfectly fine other wise. 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. Turning off and then on again, the engine returns to normal. If you go too high then the motor will not return to your target idle when you come off the throttle. Your mechanical advance will naturally change the timing a bit but it should be fairly close. Some advanced conceptsIf you have the Sniper Can-Bus to USB Adapter, you can connect your laptop, open the software to the learn table, and get a visual for where in the table you are experiencing the lean bog. Any idea's? 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 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. So glad this was helpful. 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. Capability Range: Advanced Fortunately, these are much easier to solve. Use the idle speed screw to set the idle at a comfortable warm-up speed. The headache is the Acceleration Enrichment. It sounds like you need a bit more of a fuel squirt on acceleration, Brett. Thanks for the great question! But I still get the iac at 0 and the rpm at 1200. Getting the throttle blades and IAC to work together will keep your fuel injected hot rod running smooth and predictable. Thanks, That is an strange situation. First thing I would check Well, it turns out that with the current firmware this throws the IAC control into a bit of confusion. If i set the idle to 750, the only way i can get it there is to turn the idle screw all the way out but then its at 0 iac. 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. Reply Quote. But if I take off from a stop and go to 1/4 or 1/2 throttle its fine and takes off like a banshee. Fuel Flow lb / h = 12.1 It drops about 200rpm when clutch engages. In the Wizard, select the stock cam setting. I can get it to fire up on the Some have suggested mis-setting sets the idle speed at 850 RPM but I suspect it is not a fixed number but rather a delta of about 300 RPM above the target. Idle was around 1000 mark and iac 0. If the TPS is 1% or below then the air is coming from somewhere else. This may require shortening or lengthening a rod. Also if I give it a 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. I was 20 minutes into a drive yesterday when all of the sudden the RPM increased not commanded. It's going to be really difficult to nail down the problem with the several simultaneous changes that you've made. I think you'll be all set! Hello Chris. Ok, so I'm stumped! Definitely would have went with you guys. However, I have never found that to be the case. Glad to hear that things are working well! I can adjust at 160deg, but my fans turn on at 180deg. If I keep the rpm's up it does fine but my clutch can't keep up with this for long.Also when I cover the IAC port the engine dies. I have an adapter on the manifold for squarebore to spreadbore and then a phenolic spacer. So, this is what it takes to put a Sniper on a small-block Ford. No, the idle speed curve setting isn't something that you normally worry about--and especially not down at minus 40 degrees farenheit. If you are idling at 2100 RPM (based on a default IAC Hold position of 30%) and your target idle speed is 900, then the ECU is not going to try to idle down. From herethe cycle continues and I am Common killers: No filter in front of the pump, reverse wiring, driving with PWM voltage, running at dead-head pressure.Since it sounds like your pressure is right, and since the Holley system doesn't provide a PWM voltage, that pretty much rules out everything but the lack of a filter. 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. 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. The Sniper will be controlling the timing so it will be based on a multitude of factors. This is very disappointing as people love to hear the motor while the hood is open.Thanks Jon. 63 bomb There are two ways to address this--you can let the system learn or you can manually adjust the acceleration enrichment. But another thing to consider is adjusting your target A/F ratio. They always responded to my questions with guidance that helped me choose the right system for me. Now it registers zero and I have good idle but it will not register until it hits 60 and up. Price Point: $, Advanced throttle body injection systems capable of transmission control and more. They are prone to be inaccurate. Just wondered if you've ever run across a system not powering up? I will a, Scott has been very helpful and informative on guiding me through the purchasing and installation of my terminator X max system. This is more of a bit of a reality check. it seems to ramp to 60 psi on the initial prime, but as soon as the motor start the psi spikes.I guess a workaround would be an inline return/filter regulator? :-). It sounds a little different from mine, since it commands a 1300 or so increase intermittently. That is likely just confusing the issue.Instead, choose whichever setup most resembles your camshaft and stick with that. That could be a problem with the TPS or it could be some sort of throttle linkage issue. (I'm running from a fuel cell on the garage floor 10 feet away with lines in plain sight and do see fuel coming from the return at a decent flow. You can re-enable this after you have completed this idle speed adjustment process. Is there away to lean the idle out? 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. 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. It will learn the fueling eventually either way, it's just that one might get you there a little faster.If the idle is fine at start-up but then increases after you depress the throttle then you might need to lower your IAC Hold Position a bit. It sounds a little different from mine, since it commands a 1300 or so increase intermittently. What an amazing site you have here. I've helped folks work through a number of challenges with their Sniper EFI System installations. 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. The RPM would increase for no reason. I'll give the ". Let Now I have most of the bugs worked out it runs fine on the highway and around town it's just the idle. Ensure that the secondary linkage is completely closed (both visually and manually.). I ask because I'm using a PCV valve with my Sniper and have random idle issues as well. 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. Since the shield was put on, not a single problem, not one. 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. you have it set. Took it for a lap around the block and came back. If your TPS is at zero and your IAC is at some random number above 8% (but not exactly 30%) then for some reason your engine has not met the conditions to ramp down to target idle. It turns out that some of the Snipers are shipping with the minus 40-degree setting drastically lower, as shown in the following image. When stopping, the brakes are unable to overcome the engine so I go to neutral just to stop fighting the engine.