holley sniper efi iac problems holley sniper efi iac problems

I figured out I was going the wrong direction when I was messing with the AFR programming. Clearly, something is changing. Holley Sniper IAC Problem - Holley Performance Products Forums It is easily solved by installing a four-hole gasket or four-hole spacer (depending on your hood clearance issues.) Have you confirmed your fuel pressure at idle is 60 PSI? Thanks. That is likely just confusing the issue.Instead, choose whichever setup most resembles your camshaft and stick with that. I think that the more important point is that Holley kept sending him units until everything was working. 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. The solution is to either lower the IAC hold position or increase the RPM above idle to start ramp (default is 1000 RPM). It starts cold fine, its just when its hot. The link above includes the option to buy a -6 AN 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. The throttle plates are misaligned. Thanks for all your help Chris! Free ground shipping regardless of order size! However, I have what I will call a whistle at a throttle position on 35 - 50. So what--you're never going to drive in minus 40 degrees, right? Fuel Prime Multiplier is primarily a benefit to throttle-body based EFI systems. Since the shield was put on, not a single problem, not one. I'm new to EFI and have no idea what to try next. The idle will not return to the set value.The second issue is the same as the first but the motor will stall out. Even then, recognize that over time the IAC will need to be readjusted to compensate for minor changes that will cause it to drift. A common issue we see is a result of poor fuel pump grounding running a eyelet from the pump ground to a rusty or painted surface. We are using Target AFR of 9.0: 1, Fuel Base approximately 40% higher. You could go either way.. Now that you've got your IAC set I'm going to recommend that you run your setup wizard again, which will reset the ECU to the default settings. I did notice that when I thought I had it set 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. It does this with the engine off. If the ECU has not spent some significant time learning yet, I'd recommend going back through the setup wizard and getting everything back to default. This may require shortening or lengthening a rod. IAC Testing Procedure for EFI Systems NOTE: Do not attempt to set the target idle speed and IAC position until the engine is above 160F! And Earl's makes a fantastic little 100 PSI gauge. In that case, and if you have an EGR valve, I might be suspicious of something going on there. I am having an issue with the IAC on the Sniper. After 50 on the throttle position I'm not sure if the whistle goes away or you just can't here it anymore. I have a set of 8.8 Accel Rfi suppression wires on it. I'm Having trouble with the Sniper on high Idle. The manifold pressure increases with the throttle opening but the RPMs are still low. Idle when warm was 850-ish and IAC 3-4 just as when I readjusted it the night before. Your AFR is pegged lean. But now that Terminator X is available, I highly recommend going that route. Ran 2 Holley carbs and an Edelbrock. 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. Short drives is fine then it'll The engine makes very low vacuum at idle. Seems like its too slow to grab idle when ac kicks on. And since they really had an insanely-tight monetary and real estate budget in the Sniper EFI System, it is unlikely that the added something that wasn't absolutely necessary--and then forgot to use it..And you are spot on about the little Earl's gauge with optional -6 AN port. I have installed my Sniper and the car runs great. New install, when in setup wizard TPS says 90 percent and I checked the linkage and butterflies. Holley Sniper EFI 550-552 Holley Sniper EFI Autolite 1100 - Gold The problem I believe this is creating is after I start vehicle (and its still in park), the IAC drops down to my hold percentage of 10% (since throttle % is not 0) before engine is warm and therefore causing the engine to stall out. Be sure to re-enable it once you get your idle tuned. It only lowers to 2-6% when I take my foot off the gas. Once you confirm the operation of your IAC then it's time to read my article on Solving RFI Problems. Second, Holley just released over the weekend a video on how to implement a flex fuel sensor on their HP and Dominator ECU's. I presume your idle speed table doesn't increase at 200 degrees? Data logs show no EMI/RFI. 680-700.I can't find any reason other than it looses where it is in the firmware with Idle was back to normal but iac was at 0. So, if pressing the throttle is making it start, it's because you're flooded.Which is consistent with your rich idle condition comment, right? Even at 0% it's sucking a bunch of air through the IAC port. Jump on board now! I recently bought the car with the EFI system on it. Idle > IAC Kick. I have a Holley Sniper for almost 11 month now and it was running fine with no problems until now. I have adjusted many settings and eventually mess it up and go back to the original map. 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. Um, no. But get that fuel system fixed before going any further. Thanks again. Any idea's? Bryan McTaggart 02/28/2023 news Also if I give it a 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. With the engine still idling high park, set the brake, open the hood, and remove the air cleaner. Suddenly, the engine accelerates alone, hears a great deal of air being sucked in, Any help would b great. Holley Sniper EFI You will have to do this until the TPS stays at 0% when the throttle is closed. This can cause the engine to run rough and may even lead to engine damage. Going back to what you said. Add To Cart. I've tried repeatedly re-creating the scenario in hopes that the E.C.M. It started right up and we did your idle control fix and all is good at idle. Relatively new Sniper EFI install on a '69 Mustang 302. A couple of possibilities that come to mind in order of likelihood: Im having an issue with what I think is the Iac. Also ensure the TPS Position returns to zero at idle, & the IAC Hold Position isn't setup too high. 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. Well, it turns out that with the current firmware this throws the IAC control into a bit of confusion. I then saw you guys have an awesome little gauge that can hookup inline to the snipers existing fuel feed?? Technically it is a warranty-voiding maneuver so proceed at your own risk. 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. That is the first thing you must find. Note that sometimes you can get into a back-and-forth situation. Explained: Holley EFI Sensors and What They Do )Take a look at your AFR during the starting process. 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. Thanks for the info Chris. If your fuel pressure regulator has failed (and they often fail by blocking return fuel and maxing your fuel pressure) then it could lead to rich idle, particularly until your engine gets up to temp. What I can't explain is why your TPS is acting so randomly. You could install the Holley Dual-Sync Distributor and let the Sniper control your timing. When I turn it off and try to restart it just cranks. Don't try to correct for the fuel. Observing the temperature on the 3.5-inch handheld (only), wait for the temperature to achieve 160 degrees F. Once above 160 degrees, turn the idle speed screw so that the idle is about 50 RPM below your target idle speed set in step 1, above. It is a common one. )Since this isn't a consistent issue with all Snipers that tells me that different IAC settings tend to make the whistle. Take a drive and stop somewhere for 30 minutes, CTS is 170 when engine was shutoff. I also raised idle at Park a bit with the idle screw. What an amazing site you have here. The noise is definitely coming OUT of the throttle body. )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). Your mechanical advance will naturally change the timing a bit but it should be fairly close. I straightened that out, got it running and that's where it goes downhill. :-) Just don't let the parts go flying. I recently detached the TP sensor from the side of the sniper to physically move it and it still would struggle to get to 0%. that my Air/Fuel ration was 15:1 and I believe the target is 13.5:1. If you can track specific engine coolant temperatures where the engine stumbles and dies that would be a good place to start. is the fuel pressure. You can find those settings here: Handheld: Tuning > Advanced > Advanced Idle > Rampdown, Software: Idle > IAC Settings > IAC Ramp Down. If this is the case then some adjustment of the linkage or the butterfly plates themselves is necessary. 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. Holley - 543-105 EFI Idle Air Control Motor , Black - amazon.com (Note: in the original version of this post we had a section about checking the idle speed curve setting. This is more of a bit of a reality check. The IAC is hanging open and not really at 0. 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. 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. One thing you need to sync the timing and set the inductive delay. Now it registers zero and I have good idle but it will not register until it hits 60 and up. Shut off car/restart and it's back to idle at 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. You'll have to go back and forth a couple of times to get it just right. Interesting situation you have. The fuel pump is mounted under rocker panel as low as possible and far away from any heat. Confirm the placement of all wiring, ensure that the WBO2 sensor is positioned properly, etc. Or is there something else I should Not to bandstand here but this is the point when where you bought your system is so important. I watched the butterflies start to open at about 35 on TPS. This may sound crazy but I'm going to jump out on a limb here and say you don't have an idle issue--you have a timing issue. I drove it a bunch more yesterday afternoon/evening and the same thing happened several times. You are aware of the idle-up problem. 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. Holley will take a look and tell you you have RFI and wish you good luck in finding it. Is that normal? Thanks for the great question! If your mixture is too rich, it means there's too much fuel and not enough air. Using a Snap-on variable timing light so this is why I say timing is perfect. Hello, I am having a tps and idle issue. Price Point: $$, Robust, feature-rich multi-port EFI systems offer easy plug-and-play late-model V8 engine swaps. Top 10 Sniper EFI Installation Tips from Holley's Tom Kise They also worked with me on a sale I missed and price matched those parts. I keep doing that with the same result. Always had to set idle above 950. Hey Chris, I installed a Holley sniper on a small block 400, first start was great! All of the wiring exits below the rear fuel injector cover, for a completely stealth installation. You can drop it down and you will find it will behave more like you expect. 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. Yes, let me know how that setup process works. 34K views 1 year ago Holley Sniper How to Set The IAC Idle air Control in 5 minutes or less. I've made all the adjustments, all the settings, and the IAC issue is driving me crazy. The engine might run hot but if the timing is right it should keep that heat in the engine--which is where the damage turns up. You're going to have to clean up the wiring in your engine compartment, In particular, look for spark plug wires that might be running near your throttle position sensor. When I put it in gear, it drops so low that it will stall if I don't add throttle. That's a nice change of pace--a low idle issue! Maybe here will work better ?Sniper High Fuel PSIMy fuel psi is over 90 according to a brand new Auto Meter pro mechanical gauge tied in at the inlet to the Sniper using an AN adapter.I did the search function on here and found a similar high PSI issue that was fixed by clearing the return line.I have checked the return line hose for kinks and have removed it and blew thru it without any back pressure. (If you do this you will need to reset the -40 degree setting mentioned at the top of this article. There are two ways to address this--you can let the system learn or you can manually adjust the acceleration enrichment. It's pretty hard to get the header tubes glowing at idle with a lean AFR. Holley documentation and videos didn't work and the $300 I paid for "expert" tuning didn't work either. I appreciate the help youve given to everyone as it continually helps me! Since your target is probably more like 700, and since 2400 is way over 1700 RPM, it's going to leave the IAC in the park position.Buckle down and find how air is getting into your engine. If your fuel pressure is at or about 60 PSI then visually inspect the barrels of the throttle body while having someone key on the Sniper. May God's grace bless you in the Lord Jesus Christ. When you set the Static Timing to 15, what did you read with the timing light? 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. Super helpful and knowledgeable. Sniper setting is Stock camshaft. That is what I really respect about Holley. As always, I recommend great restraint in changing any of the parameters until a significant amount of learning has taken place. 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. Laptop Access No matter what do, my idle will not drop below 1350-1400 RPM when the engine warms. Copyright 2017 Cyberspace Automotive Performance, Inc. All Rights Reserved. I took some pics of the sensors page this morning after the car warmed up. (Do this while you are cranking.) Im thinking a faulty TPS. If you get into the practice of hearing all three of these sounds you will know if you have a problem even before you turn the key to crank. So this is my issue ( I did just email Holly). Does this seem reasonable and how hard will it be to get the idle and off-idle performance correct? It only comes back to normal if I turn the engine off and on again. The team at Holley has designed the perfect solution for your problems. To get it to idle the tps is at 2-3-4% even with linkage disconnected and a return spring installed. Watch videos on installation hints and if you haven't yet, download & read every Sniper installation guide you can find online. Idle quality is great, RPM is good, sometimes IAC is jumping around from 35 to 60. If you go too high then the motor will not return to your target idle when you come off the throttle. when things aren't working and this provides just that. While confirming, in the handheld ensure that the Reference Angle is set to 57.5 and that the Inductive Delay is set to 100. The motor has 376hp at flywheel and the car is a stick shift. Hot start it most of the time wont start unless I give it a little throttle. Ive tried setting the prime setting above 150 but it wont take, it always goes back to 150. There's a procedure there I can share with you if you'd like.. I've abbreviated it just a little bit but am appreciative of the added insight your comments provided.Off-idle performance can really be a challenge to self-learn but be assured that it can almost always be done. How To Adjust Iac On Holley Sniper I think that your Sniper system is working fine but would definitely check ouf the fuel pump. This is actually more troubling than the sound you originally described. port that goes right on the inlet of your Sniper and makes installation a breeze.If your fuel pressure is solid at about 60 PSI then you should start looking at idles good, runs amazing. 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. Idle quality is great, RPM is good, sometimes IAC is now between 2 and 5 exactly where it should be. Just getting it to act right at startup is a struggle. Switch power to the Sniper on and crank the engine. nothing stays steady. Ensure all your sensors are displaying proper values. When I first told him to check for leaks he looked back there and said "all good". itself out and hold idleeventually stalling. I recently had IAC issues identical to what you describe. In most cases the IAC (Idle Air Control) circuit is the source of the whistle. Strangely, what I've seen is that it idles too lean as the injectors are effectively shut off.Thanks again for the follow-up and glad to hear that everything is working well now. If the TPS reading on your Sniper EFI System does not reset to zero that is a problem that needs to be addressed. What should I be looking at to calm this down? Hi Chris, I have a lean stumble on throttle tip in 2-3% tps taking off from a stop light the afr will go to 19afr and the engine will stumble for a split second. If there is an issue with using the Sniper EFI TPS signal, is there a remote TPS or an adaptor for the Sniper EFI that allows the TPS signal to be accessed for the transmission. Keep in mind that at 60 miles the back upthe RPMs shoot up to anywhere between 1500 and 2000 and they will not get The very first thing I would do is get ground truth on your timing. It's all part of the adventure! 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? The fuel pressure regulator in the Sniper is fairly simple and not prone to failure, as far as I know. Tried that and it didn't work? Ive had an idle at neutral as high as 2400 rpm. Ok, so there are a couple peculiar things going on here. EFI System Pro had everything I needed for my EFI upgrade. I'll bet you find that you can get it working great without any manual tuning. If I go any more it will ping. Give it a watch: https://youtu.be/7SO7-tZn6iw. first attempt but as it tries to idle down to the target RPMsit can never even Don't know if I should put this in a separate post. They also recommended that their ground be spliced into the Sniper ground as close to the Sniper as possible. If this is the case then I would look particularly close at the IAC hold position and IAC ramp start.Let us know what you find and what works for you! Part# 538-13. This happens no matter how much I adjust the idle screw. If the solutions suggested above are not working then you need to review my article on IAC Testing Procedures. Thanks so much for reading! That, on top of your air leak, is allowing the engine to idle at 2400 RPM. We've already tried adjusting the Acceleration Enrichment chart in all ways, going up and down, RoC Blanking, everything, it has no effect. Really appreciate the amount of learning im getting off here. 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. 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. Let me be perfectly clear: If your engine will not drop below 1350 RPM with the idle speed screw turned all the way out then you have an air leak.