If your TPS has snuck up to 2% then your IAC will be at the hold position, which by default is 30%. No, the idle speed curve setting isn't something that you normally worry about--and especially not down at minus 40 degrees farenheit. 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. I have one customer who is having some similar issues and his AFR is down at 9.6:1 when it won't start. 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. Thanks. After only running for about 15 minutes or so the system starts to fail stalling the motor. It is how the engineers allow you to clear a flood condition when you detect it. Idle was back to normal but iac was at 0. Hi Chris. So glad this was helpful. Is this an issue to worry about? If you can track specific engine coolant temperatures where the engine stumbles and dies that would be a good place to start. I installed a sniper efi system on my 1969 Camaro. Changing the rpm curve and target rpm has no effect. If the connection is loose it will cause the system to shut fuel off because the signal telling the EFI the motor is turning stops (to prevent excess fuel from being dumped in the motor). If more info is needed just ask. 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. 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. In this short video you learn to replace the IAC. After 50 on the throttle position I'm not sure if the whistle goes away or you just can't here it anymore. Hopefully replacing the pump again will resolve both issues. 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. The "PC Text" indicates what will be shown on the PC/Laptop data monitor or data logger. So you installed your Holley Sniper. Mechanical Fuel Pressure Gauge on the inlet of your Sniper, now is the time. One of the great features of Holley's Sniper is the ability to set your air/fuel ratio (AFR) where you want it. Having a TPS that won't go lower than 9% will affect the acceleration enrichment correction, and could create a stumble at the first moment of throttle opening.Yes, the IAC can and will fluctuate depending on changing conditions. That So, this is what it takes to put a Sniper on a small-block Ford. I had a customer who struggled to understand that. What I can't explain is why your TPS is acting so randomly. such high fuel pressure. Those little 1/8 NPT gauges are pretty inexpensive and generally pretty easy to find locally.If you confirm that the pressure is indeed 90 PSI you could pull the fuel pressure regulator apart and check it. I presume your idle speed table doesn't increase at 200 degrees? Two things to keep in mind as you do that. If this is the case then some adjustment of the linkage or the butterfly plates themselves is necessary. If you feel you have no other choice but to run a Sniper and stand-alone controller then you can give this a try. Should the iac% fluctuate? Last night I tried setting the IAC and had the same problems after it's warmed up. 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. One of the best Ive seen so far. $107.95. I have replaced the IAC motor and the problem remains. One way is to very carefully watch the handheld monitor, and that may be adequate. Two months fighting, cursing, not getting any help from Holley OR the forum, and a stupid little tin plate. Also what would you say a desired idle should be for a 3 speed automatic ford? If the screen shows iac at 0 and you block the hole to find it open what does that mean? The fix? My problem is low idle. And so glad you guys are enjoying the Sniper EFI system. Add To Cart. And your question is very perceptive: You must first know whether the bog is a lean or a rich condition before you can make the correct adjustments. Eventually the IAC will drop back to zero, I'll readjust it to 850 RPM & 2-9%, and then watch it steadily climb again. 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. I've read that a spacer with 4 individual holes will solve this, but after I installed the progressive linkage the noise went away!! check out the. Good luck! Hello. If I adjust idle screw out to get the tps to zero or even 1% the engine will not idle. As I said I didn't buy from you so you don't owe me anything. Running the vacuum advance and of course I time it disconnected. Turning it off and back on would reset it, and then it would work as advertised for a while. I've changed all the Drive great and idles perfect at stop signs. Glad to hear that you have timing control enabled, Gary. The Sniper Quick-Start Manual provides the following instructions for setting the idle. The biggest issue is these problems are intermittent meaning they do not occur all the time. I'd say make sure you buy from someone who can give you good after-purchase help (hint!) They always responded to my questions with guidance that helped me choose the right system for me. !I called Holley today, and before I could even described the symptoms the Contact whomever sold you your system or Holley directly. I very pleased with the performance, it is a huge improvement from the 800CFM carb I had on this motor. PDF Sensor Diagnostics and Statuses - Holley My IAC and TPS show zero when it does this. They are prone to be inaccurate. Those don't impact the way the engine runs and can cause the whistle sound you describe. How To Adjust Iac On Holley Sniper IAC Calibration / Hanging rpms | Team Chevelle This page was generated at 12:25 AM. Drives just fine but won't stay running unless I keep my foot on the gas. My dad wanted to recheck the timing so I set the Static Timing at 15 and it runs perfect. It could be a couple of things. Target AFR, A / F = 13.5 MAP Sensor. If you did not rotate the distributor to set the actual timing to 15 that might be the only issue. I readjusted my IAC, now it's perfect. TPS% = 1 Seems to be working. 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. Sniper setting is Stock camshaft. Don't try to correct for the fuel. Realize that when you drop the throttle, the engine enters a condition it will only see for a fraction of a second at a time. I recently bought the car with the EFI system on it. They tell you to ask call Holley. Thanks for any help. Good luck! 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. 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. But as you see from the recent revision I did above you seem to be having a fixable issue. What would cause the idle to faulter like that? Could be a bad IAC motor, replace it and see if that solves the problem. Confirm the placement of all wiring, ensure that the WBO2 sensor is positioned properly, etc. ChrisI finally got everything resolved. Thanks for the info Chris. 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. check out the. It sounds a little different from mine, since it commands a 1300 or so increase intermittently. I chased that gremlin for about three weeks and was convinced I had a bad throttle cable. Holley Sniper IAC Problem 04-26-2018, 11:30 AM Hello. Has a good size camshaft cant find any vacuum leaks. If I put the truck in park it comes down to idle. Your issues are likely related to one of these two things. AGAIN This is Intermittent meaning on a recent trip I stopped 3 times and issued occurred once. I'm wonder if the iac can cause this. I have probably 200 - 300 miles on this engine and it has always done this. Thanks, That is an strange situation. Idle Tuning is a very important part of tuning any EFI system, especially our self-learning units like Sniper or Terminator X EFI. If that happens then follow my 10-step process shown above. So the issue Im having is low idle. Fuel Flow lb / h = 12.1 Fortunately, I have an article that goes into this in some detail. Once we recognize that, the next step is to narrow down all possible sources of additional air until we discover the cause.Start by keeping an eye on your IAC number. When I drive with warm engine the IAC is at 30% when pushing gas, but shouldn't it be at 0%? What might cause the TPS to go to 2%? Have a look--I think this is going to allow you to fix your idle problem. Price Point: $$, Robust, feature-rich multi-port EFI systems offer easy plug-and-play late-model V8 engine swaps. Generally, one of two things: a stuck throttle or noise on the TPS signal. IAC Pos.% = 0 TP range is normal goes up to about 90% with throttle pedal to the floor. I am new to the EFI scene but want to learn. I think you'll be all set! If you use your handheld to go here: 63 bomb 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. I hope everyone enjoys this v. 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. 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. If you haven't installed a I installed the Sniper on my 1978 Ford F-100 with a small block When I shut it off then start it Check fuel pressure too (. technical rep said "You ahve high fuel pressure". 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. It shuts off when coming to a stop sign, at any cruising speed and romdomly at idle in park but never when excelerating. Look over all of your vacuum lines and fittings. Solving RF Interference Issues in Sniper Installations - EFISystemPro.com Engine has never stalled with Sniper system, once placed in Drive it just goes!!! On EFI systems such as Holley's Sniper, all of the EFI sensors (except for the O2 and coolant temperature sender) are mounted snuggly in the throttle body. MSD pro billet and 6AL box Bolt-on carburetor style EFI for your classic car or truck. Since the shield was put on, not a single problem, not one. I would only play with this if you are finding that the other adjustments I suggested aren't working. When I put it in gear, it drops so low that it will stall if I don't add throttle. A question I cannot get a 100% answer on is can you piggy back off the Sniper EFI TPS for an electronic transmission? To figure this out it's going to be important to gather a bit more data. Though it started and ran good, it was dumping fuel and would not lean out to AFR set points. You can find those settings here: Handheld: Tuning > Advanced > Advanced Idle > Rampdown, Software: Idle > IAC Settings > IAC Ramp Down. Price Point: $, Advanced throttle body injection systems capable of transmission control and more. Please let us know how this works out for you! Hot start it most of the time wont start unless I give it a little throttle. Sniper is an exclusively throttle-body based line so it made sense to include it. Pricing was reasonable, shipping was prompt and Chris helped me with a wiring question during my install. Why is this? EFI Systems based on Holley's world-class Dominator and HP ECU's. To get it to idle the tps is at 2-3-4% even with linkage disconnected and a return spring installed. :-DStill, I hate to leave someone hanging so I'll try to help. Have you confirmed your fuel pressure at idle is 60 PSI? carburetor setup, but it does blow when I can't jump on the highway like I use Does anyone have photos of this additional return spring they installed? 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. A good example of why it's so important to run a good pre filter in the fuel line. It then idles up from 750 to 1100. Capability Range: Advanced 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. After doing TPS reset it starts fine but when you give it some gas it hangs at 1500 and will not return to idle. I have certainly seen this before on other fuel injected vehicles when hot. First--besides the fact that it's not represented on the display, it is not even a parameter that you can datalog. Tried that and it didn't work? Full product line and accessories at excellent pricing. Except at idle. I managed to get the IAC down to around 0% - 8%is this good? Then it started behaving oddly. 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. 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. If your mixture is too rich, it means there's too much fuel and not enough air. When you set the Static Timing to 15, what did you read with the timing light? In that case, and if you have an EGR valve, I might be suspicious of something going on there. The problem I experience is that after driving for about 10-15 minutes, the car starts idle to high. Ok, so there are a couple peculiar things going on here. Do you have any clue? A couple of those and you should feel it getting better. However, whenever you start changing things, you can get into a chain reaction. Without it you are working in the dark. I followed the instructions and set the IAC to 2-9% when warm with idle at 850 RPM. Once you know that then you can work on those problems. There is no real mystery here. 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. Both Sniper and trans controller grounds were direct to the battery ground, as they should be. There's a procedure there I can share with you if you'd like.. The ticking is inline with the fuel pressure I feel squeezing both the fuel return & delivery lines (like a heartbeat). Just thought I'd ask as there isn't a lot of info out there. TPS 0. The 10 step set up on your page set my idle perfect and iac perfect a very consitant 700. FYI: Car is a 1970 Mustang 302 Ford Racing roller motor. IAC Creeps To 100% - Holley Performance Products Forums Intermittent stalling usually points to radio frequency or electro-magnetic intereference (RFI/EMI). Several good bits here. I installed a Holley Sniper on my Ford Maverick 302 V8. You've got it running and warmed up but now you need to set. 90% of problems, (INCLUDING MYSELF) could be answered/fixed by just reading the instructions. I'm new to the efi thing and any help would be seriously appreciated. The motor has 376hp at flywheel and the car is a stick shift. )Then look a the datalog and find out what TPS ROC and MAP ROC is most likely to cause the problem. So check that timing and I think that you're going to find you need a good bit of advance. 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. We're never going to fill up your email box with nonsense. When I put it in gear, it drops so low that it will stall if I don't add throttle. Inj. Just getting it to act right at startup is a struggle. It felt like it was flooding out at low speed, low. Thank you in advance for your help and providing us rookies with your 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 tps will not auto reset to zero. Bottom line ismy first one must have been faulty. Doesn't want to start, runs like crap. So I had my Idle set up perfect, with idle timing control off and engine hot the IAC was right at 2-4%. If But get that fuel system fixed before going any further. If idle drops below 800 it wont come back itll chug around 300 rpm for a few seconds then die. I've been messing around for a bit trying to eliminate any possible vacuum leaks. any advise would be appreciated. I went on the good ole interweb and found your website which was VERY helpful! Your suggestion to remove the PCV valve is just for diagnosis purposes, right? 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. Then, the next time I cranked it, the idle went high and won't come down!" I have driven a stand-alone transmission controller for the 4L60E in my (then) Sniper-equipped '95 GMC pickup using the Sniper TPS with complete success. The throttle plates are misaligned. I will turn it up some. I have a Holley Sniper EFI with HyperSpark ignition. The solution is to either lower the IAC hold position or increase the RPM above idle to start ramp (default is 1000 RPM). Or ?I have put a fuel pressure gauge right at the inlet of the sniper and it is reading 60-64 psi. knowledge with the sniper efi setup. If you do find you have RFI issues then I've written an article on solving RFI problems. The window you saw in the image above pops up. An undersized or partially plugged fuel filter is a classic EFI installation mistake. We are running a Sniper on my mates 355ci small block V8 & so far he is very impressed ! And Earl's makes a fantastic little 100 PSI gauge. I've not heard of any others with this exact issue so I don't think it is a common problem. Second, Holley just released over the weekend a video on how to implement a flex fuel sensor on their HP and Dominator ECU's. 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. If you remove the air cleaner entirely and the whistle continues then you can rule that out. 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. Sniper EFI Update: Weeks Later, Do I Still Feel It Was Worth It? This question is really outside both the scope of what we try to discuss in the comments section as well as the overall subject of this article. Any idea's? It may take a few tries. And thanks again for taking your time to answer these questions. I have heard some guys complain that the idle is too good and they can't hear their cam anymore I'm kind of like that. IAC percentage is 5 to 10% when idling with fans on, What you're experiencing is the delay time between the ECU sensing the additional load and the IAC actually increasing the RPM. You're going to have to get this fixed or it's going to cause even more problems than the high idle. I think you will find that it will learn its way through this. I thought 12.0 was leaner at idle, but I figured out I was wrong.lol. It drops about 200rpm when clutch engages. Sometimes it sounds like it wants to crank at the start but runs out of gas. What I would recommend is getting somewhere that you can spend a significant amount of time doing starts. One of the most common symptoms of a Holley Sniper EFI problem is an air/fuel mixture that's too rich or too lean. 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 It's pretty hard to get the header tubes glowing at idle with a lean AFR. The distributor was loose. Ive also used another snap on light to confirm. You have to remove all hoses in order to debug the problem. With the vehicle in neutral, adjust the idle screw until the IAC Position reads between 2 and 10%. Tuning Your Sniper EFI System for Progressive Secondary Link Use While confirming, in the handheld ensure that the Reference Angle is set to 57.5 and that the Inductive Delay is set to 100. Hey Chris 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 I've helped folks work through a number of challenges with their Sniper EFI System installations. 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. This may require shortening or lengthening a rod. So as much as I can I have been taking off real slow and let it fall on itself to try to learn and its not learning its way out of it. Ensure all your sensors are displaying proper values. Is there away to program the ecu to compensate for this at start up. Idle : IAC Rampdown : IAC hold positionChange this by maybe 2% in either direction. 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. Seems like its too slow to grab idle when ac kicks on. I have installed my Sniper and the car runs great. You can drop it down and you will find it will behave more like you expect. other things that might cause the idle to faulter, but this is a good start. I'm new to EFI and have no idea what to try next. Solving Holley Sniper High Idle Issues - EFISystemPro.com Should i adjust idle screw with the fans already on? The Tech Tips and discussions are also great! Perfectif you have the original synchronous linkage. It meets the target idle perfectly in either but if I lightly stab the throttle it tries to stall after slightly revving. We'll also be contacting you for future purchases now that I've discovered you! Its on a big block Mopar with stock electronic ignition . I think I figured some of my problems outI'll try to explain. Sniper EFI Initial Startup and Troubleshooting Staff Writer 01/20/2020 We offer some tips to help with that. 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. Holley Sniper EFI Problems: Best Fixes According to Manufacturer Price Point: $$$. The engine ran so good, I would have never suspected the Fuel Pressure to be an I did check for the lightning under the hood but all was well. Sniper EFI Problems - Holley Performance Products Forums shut truck off. My sniper is doing two thingsFirst issue, the idle is set at 800 and will idle fine, then There is a glitch in the system. I tried adjusting my IAC up to 10deg in both directions with no change. The Sniper EFI Manal says not to but many EFI installers have informed me that the transmission only reads the 5V TPS signal from the Sniper EFI & does not draw any power so will not affect the Sniper EFI TPS output. It really takes a lot of throttle tip-ins before you get anywhere near "learned" in this part of the fuel map.Based on your description, it sounds like you have a lean stumble. But if you will just advance the timing at idle and see if it makes a difference then that will tell you what you need to know. = 2.34 IAC Testing Procedure for EFI Systems I have never seen issue when CTS is below 120 degrees. :-). There are two ways to address this--you can let the system learn or you can manually adjust the acceleration enrichment. I'd recommend you contact Holley Tech support to get their input (1-866-464-6553; call early for the shortest wait times.) When I see that your TPS is 1%, that tells me that you may have an RFI problem. That is the first thing you must find. Thank you very much. I believe because the TPS is not registering. 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. I can adjust at 160deg, but my fans turn on at 180deg. Do I have to hook up sniper ac wire to relay or should iac pick up idle? Holley - 543-105 EFI Idle Air Control Motor , Black - amazon.com While this video is not meant for the Sniper EFI user it does provide a great overview of how your ethanol tuning adjustments must be made not only to the base fuel map but to the other configuration settings. That 60% (which is configurable) is known as the Clear Flood TPS. your IAC is at zero. The first thing I'd do is check your fuel pressure with a gauge like this. I did buy the Sniper from you guys and the service was fantastic. When I put it in park the idle RPM was 2100-2200 each time. Chris's Idle Speed Adjustment Instructions*: *Note: If you are using your Sniper to control ignition timing then I recommend that before you start this process you disable idle spark control If you are trying to do this while the ECU is simultaneously trying to bring your idle under control by adjusting the advance it is going to be counter-productive. Hope this helps! 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.) 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. Data logs show no EMI/RFI. Start engine let it warm up to 160, learn mode is learning. Sorry I didn't buy from you but I didn't know you had sold them. engine works beautiful, the car runs a lot, but suddenly, the engine does that. So if you are trying to achieve a stoichiometric mixture in ethanol (which is achieved at an AFR of 9.0:1) then you should continue to target 14.7:1 since that is what will be displayed. The Sniper even has a feature that allows it to use the idle timing to control the idle speed. ?I never had my Carb Cold start RPM any higher then 1600 RPM.THANK YOU. Jump on board now! It didnt do this with the carb on it. I am right back to where I started. Now, 1% on the TPS isn't a problem, but when it goes to 2% (which is inevitable if you have RFI moving it to 1%) then the IAC is going to go to it's hold position (30% by default) and the engine is going to rev up. I think in some of the Wizards with the handheld it doesn't use 57.5 as the default. 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! He thought that something was wrong because when he set the idle 50 RPM below his target the resulting IAC postion was far too big. The idle is 1350-1400 with the idle screw at initial contact.