That, on top of your air leak, is allowing the engine to idle at 2400 RPM. 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! 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! 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. Unfortunately I did not buy my sniper efi from you. That's a nice change of pace--a low idle issue! What is it supppse to be at idle and while driving under heavy acceleration? I'm running a 408 sbc. Sometimes it sounds like it wants to crank at the start but runs out of gas. All in all, considering the system has been installed for less than 2 hours drive time we're BLOWN AWAY at how quickly it is "learning" this engine. They tell you to ask call Holley. Short drives is fine then it'll Closed Loop Compensation rises to 100%, Do I just keep pushing it the same way to Your suggestion to remove the PCV valve is just for diagnosis purposes, right? If your RPM is 2000, your TPS is 0, and your IAC is not closing, then there is some problem. I pulled over and turned the car off and then back on. 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. Robust, feature-rich multi-port EFI systems offer easy plug-and-play late-model V8 engine swaps. 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! You can disable the idle spark control at the locations below. One way is to very carefully watch the handheld monitor, and that may be adequate. FYI: Car is a 1970 Mustang 302 Ford Racing roller motor. I put sniper on in hopes to be able to just turn key and start without fumbling with pedal to keep it going and to correct idle drop when ac kicks on. I used the Casper's Electronics 108103 splitter and carefully soldered my connections. Hello I installed my Sniper and the engine fired up great. I can adjust at 160deg, but my fans turn on at 180deg. View Holley Sniper EFI Self-Tuning Kit - Shiny Finish. RPM = 1200My slow gear I leave with 650 RPM, the IAC Position I leave between 5 and 6%, the But I think it is safe to say that you are now at a point were some manual tuning is a good idea. Cracked casing from a side cover screw being installed crossed threaded. Bolt-on carburetor style EFI for your classic car or truck. I have not heard of this. When you set the Static Timing to 15, what did you read with the timing light? 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!) I' m going to put the 3 rd new pump this coming friday. Running a bbc with coil - my timing is perfect. I have a bone stock 350 that I installed a Sniper on and had the same whistle noise, presumably from air going past the butterflies. If you're having issues with your Holley Sniper IAC getting stuck at 20, there are a few things you can try to fix the problem. 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. Am I missing something. It could be that you've left a vacuum port unplugged, it could be that the throttle plates are misaligned (unlikely), it could be that your IAC is not closing properly. Your comment doesn't imply any sort of problem that would make me give up on idle timing control. Or ?I have put a fuel pressure gauge right at the inlet of the sniper and it is reading 60-64 psi. I' m going to put the 3rd new pump this coming friday. Took it for a lap around the block and came back. 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. i would have been happy to answer there. is train the system or there is actually something wrong.I do love the system at I straightened that out, got it running and that's where it goes downhill. The Sniper EFI remote IAC (Idle Air Control) and plug is designed to gain installation clearance on some Sniper EFI 2x4 installations. Also when ac kicks on it will idle down and stall. When you have the issue you should disconnect all hoses and plug the ports on the Sniper. Fuel Prime Multiplier is primarily a benefit to throttle-body based EFI systems. I believe that for the HyperSpark the Reference Angle should be 57.5. I went on the good ole interweb and found your website which was VERY helpful! 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. Then a little faster--until bogs at that level work themselves out. Start by doing the fastest start you can that doesn't bog. Does anyone have photos of this additional return spring they installed? Since the load is more of a wave that increases the most initially and then decreases again, the ECU is doing really well to get the idle under control in only two or three over/under shots as you describe.You don't mention if you have your Sniper ECU controlling timing. Throttle Tip-In tuning can be a bit of a challenge but I'm confident you can get this resolved, Mike.Let me start by saying that unless you've really done a lot of driving on the system in some useful learning situations then I would set this issue aside and not even think about it. Hi Chris , greetings from Down Under (AUS) Just a note on the hi fuel pressure issue . Worst case you'll have a spare on hand, and if the TPS is faulty you will have solved the mystery. Chris, Do you have any clue? If you go the other way then you might find that the IAC zero's out when the fans are off. 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. Clearly, something is changing. As you see above, the Sniper is going to dump in a maximum amount of fuel at zero TPS, begins to remove acceleration enrichment at 60 percent TPS, and then removes all acceleration enrichment correction at 100% TPS. The solution is to either lower the IAC hold position or increase the RPM above idle to start ramp (default is 1000 RPM). Others might require 60 RPM. Hi Chris. 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 have been able to get it pretty 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. OK, I did the baseline idle speed screw setting. 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. When running it will only stay in closed loop and learn at idle. Wish I knew about it before I made my purchase. Now it registers zero and I have good idle but it will not register until it hits 60 and up. Thank you. Good luck! 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. Im not sure what its doing, have messed with after start fuel, fuel at cranking. The last pic is with the car in Drive. Why is this? Even at 0% it's sucking a bunch of air through the IAC port. P.S. 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. Idle when warm was 850-ish and IAC 3-4 just as when I readjusted it the night before. Ive tried setting the prime setting above 150 but it wont take, it always goes back to 150. I think you will find that it will learn its way through this. Get a solid feeling for where it is when the engine is warm and the idle speed is correct. An under-sized filter will allow part- throttle operation but fuel pressure will drop at WOT and run very lean - perhaps surge under power. It does this with the engine off. You advise would be greatly appreciated. The motor has 376hp at flywheel and the car is a stick shift. Capability Range: Advanced I also noted that after some time, I could change those values as I saw fit. After much diagnosis, I ended up replacing the intake manifold gaskets. Hello, I am having a tps and idle issue. Using the handheld, navigate to Tuning > Basic > Basic Idle and ensure your target idle speed is set to the RPM you desire. The jack-rabbit start can usually be minimized by adjusting the throttle linkage. 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. 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. Hang in there--you can do it. I followed the instructions and set the IAC to 2-9% when warm with idle at 850 RPM. I certainly appreciate your frustration (as well as your wife's!) I put it in neutral and the idle RPM had increased to 2100-2200. that my Air/Fuel ration was 15:1 and I believe the target is 13.5:1. Was perfect idle iac reading 3. I will let you know what the results are. I'm happy to walk you through what is required. But he kept having problems so eventually he did a complete check and then he found the problem. But get that fuel system fixed before going any further. Anyway I have a 327 sbc in a 1987 Monte SS with a T5 5 speed and 3:73 posi rear. It's not that they (or any other manufacturer) is 100% perfect. I would suggest you take a look at that if you haven't already. Suddenly, the engine accelerates alone, hears a great deal of air being sucked in, Even at 0% it's sucking a bunch of air through the IAC port. It starts cold fine, its just when its hot. Idle : IAC Rampdown : IAC hold positionChange this by maybe 2% in either direction. If the IAC is zero, and if putting your finger over the IAC port doesn't lower it, then it's not the IAC circuit. In that case, and if you have an EGR valve, I might be suspicious of something going on there. :-). 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. Earl's Mechanical Fuel Pressure GaugeI could use that for a quick troubleshooting for 1/3rd the cost of the Holley one. Yes it is controlling the timing and I had issues at first and it controlled the idle just fine. Mechanical Fuel Pressure Gauge on the inlet of your Sniper, now is the time. 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. We have shipped quite a few of these to customers in Australia and New Zealand so I know that there is becoming a good following there!We recommend this Inline 10-micron fuel filter to prevent problems like that. 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. Once you so this, and after you have your CAN-to-USB harness attached to your laptop with the Sniper software, you can see precisely the cells where the system is operating when the bog occurs. When you experience this, before you touch anything or shut the engine down, first look at your TPS and your IAC. I think that your timing is too retarded. And the rather cavalier "Absolutely!" It appears that I could now use the dongle and a laptop to custom tune for idle issues if needed. Chris, I recently installed my Sniper and have an intermittent idle problem. Thanks for any help. 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. If you go too low then it may stumble or even stall when coming off of throttle. Thanks Again for your help. Thanks, That is an strange situation. The manifold pressure increases with the throttle opening but the RPMs are still low. I.e. 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). If you feel you have no other choice but to run a Sniper and stand-alone controller then you can give this a try. The fuel pump is mounted under rocker panel as low as possible and far away from any heat. If the issue persists, you may need to replace the IAC. He is able to get it to start by quickly depressing the accelerator to at least 60% and releasing. 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. First, let me congratulate you on your patience in letting the system learn. Inj. 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. The problem I'm having is I cant get the IAC to drop down off 100%. Thank you for any advice. Hello, Chris, thanks for the help.I have not installed the software yet, and I'm having trouble with two cars. The fix? If the solutions suggested above are not working then you need to review my article on IAC Testing Procedures. 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. First thing I would check It started right up and we did your idle control fix and all is good at idle. While it is not mandatory, I recommend the Sniper EFI CAN-to-USB Adapter to move the data between your Sniper EFI and your PC rather than trying to do this via the SD card. I chased that gremlin for about three weeks and was convinced I had a bad throttle cable. But after sitting static idling for a little bit, the IAC goes to 100% & stays there. 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. 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. Not to bandstand here but this is the point when where you bought your system is so important. When I put it in gear, it drops so low that it will stall if I don't add throttle. Get On The List for Emails Straight From Our Pro? check out the. lower until I turn down the set screw. back upthe RPMs shoot up to anywhere between 1500 and 2000 and they will not get It's called tuning. Comp. Cl. First, recognize that the IAC and the TPS are not inter-related in any way. Sniper EFI Idle Tuning. Two things to keep in mind as you do that. There are two ways to address this--you can let the system learn or you can manually adjust the acceleration enrichment. I've made all the adjustments, all the settings, and the IAC issue is driving me crazy. 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? 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. carburetor setup, but it does blow when I can't jump on the highway like I use I did buy the Sniper from you guys and the service was fantastic. Wish I had bought my sniper from you, but unfortunately didnt. 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. So you installed your Holley Sniper. If you can track specific engine coolant temperatures where the engine stumbles and dies that would be a good place to start. Then do it just a bit faster--just enough for it to bog a bit. It only comes back to normal if I turn the engine off and on again. Holley Sniper EFI Troubleshooting Mudford Garage 8.6K subscribers 38K views 3 years ago My Bronco with Holley Sniper EFI was running poorly. No air should be able to pass. 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. If you suspect this then try to find a situation where this occurs where you can safely check the secondary throttle shaft and see if i's slightly open. Hello Chris. *Possible delays due to Covid-19 click for more information. This is extremely unreliable afrer warm. Great work, expert! 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? Glad to hear that things are working well! That is the default "Clear Flood" TPS setting and turns all fuel off until the engine cranks.