holley sniper efi iac problems holley sniper efi iac problems

It then started working normally again. Then Friday night as I was driving home, the car started acting up. If it creates an issue (not normally the case) then you'll know. I had a customer who struggled to understand that. See these. I have turned ignition off turned screw in 2 turns and turned ignition back on and tps is at 1-2% not sure whats going on. Hopefully replacing the pump again will resolve both issuesWhoa. Relatively new Sniper EFI install on a '69 Mustang 302. 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 am having an idle issue (other than that is absolutely perfect). What you are experiencing is rather common. Thanks for your very detailed question! 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. These will fix the noise but if the performance is suffering then likely you won't see any difference since it is not likely to be related to this sound. What I can't explain is why your TPS is acting so randomly. Shutoff engine wait 30 seconds, turn key wait for display to come up, start engine. I asked him a million questions and waited a long time to save up before purchasing the system and I have asked a lot of questions throughout the installation process. I looking for your expert opinion. The jack-rabbit start can usually be minimized by adjusting the throttle linkage. Shut it off and immediately restarted and idle was now 880 with IAC at 8.If this is a vacuum leak I can't figure out what would cause it to go away immediately after shutting down the car and restarting. It is how the engineers allow you to clear a flood condition when you detect it. 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. (Don't drive and watch--get a helper!) 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. But he kept having problems so eventually he did a complete check and then he found the problem. If I try and get the 2-10% i get all the way up to 1200 rpm. THANK YOU for the "First--Check Your Idle Speed Curve Setting!" Idle quality is great, RPM is good, sometimes IAC is now between 2 and 5 exactly where it should be. :-). You are looking in the right area but I would probably not change the ROC blanking. Camshaft is M-6250-B303 .480 lift intake & exhaust, duration at .050 is 224 degrees for intake & exhaust. If your RPM is 2000, your TPS is 0, and your IAC is not closing, then there is some problem. check out the. When the system is up and running the fuel pressure regulator inside the Sniper is making a rattling sound like a shaking a paint can. Chris, I recently installed my Sniper and have an intermittent idle problem. When I covered the IAC with my finger, the RPM dropped so low it stalled. TPS% = 1 The following are status commands and diagnostics for sensor and various parameters in the Holley software. It then idles up from 750 to 1100. It's called tuning. Idle when warm was 850-ish and IAC 3-4 just as when I readjusted it the night before. 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. 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. 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. 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. When I finished the install on my C10, I set it as follows: 13.1 at idle, 14.2 at cruise, and 12.9 at WOT. 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. However, whenever you start changing things, you can get into a chain reaction. (Plus they it just looks way cool in your engine compartment!) Do I need to try taping up the IAC port and setting the idle off the idle screw? I had HIGH Idle issue and fixing this curve FIXED the ISSUE --- THANK YOUCan you explain what "Current Learn % means, after finally fixing the idle problem this % jump from -1 to -30% in about 5 minutes at idle with CTS @ about 170.Also when starting the car at hot the engine goes to about 2300+ RPM for a few seconds then crashes down to my Hot idle speed of 950 -- bounces a little and then smooths out. And yes, monitoring the fuel pressure is the right answer. 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. Price Point: $$, Robust, feature-rich multi-port EFI systems offer easy plug-and-play late-model V8 engine swaps. I have adjusted many settings and eventually mess it up and go back to the original map. So you installed your Holley Sniper. I presume your idle speed table doesn't increase at 200 degrees? 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. I hold my foot steady in place it does this in 5 second cycles and if i let go of Remember that as an EFI System Pro customer you have access to me at any time via my cell phone. About two minutes after I get it set at 850 & 5%, it has progressed to 100%. Thanks for the information you have provided on this site. back to trying to zero down an idle. 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. I recently install a sniper efi. I thought 12.0 was leaner at idle, but I figured out I was wrong.lol. Incorrect connections will result in excessive resistance. Add To Cart. 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. Then why don't you Get On The List for Emails Straight From Our Pro? The engine has 14: 1 compression ratio, we can not use gasoline. Holley have given a new unit. And thanks again for taking your time to answer these questions. If I put the truck in neutral the TPMS will raise all the way up over 2000. 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. 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. (Do this while you are cranking.) Of the two options, I generally recommend the self-learn. Going back to what you said. If your TPS has snuck up to 2% then your IAC will be at the hold position, which by default is 30%. The fuel pressure regulator in the Sniper is fairly simple and not prone to failure, as far as I know. 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. If I rev the engine a couple times in neutral it will finally return to idle & usually will not do it again for the rest of my trip. Even though the Sniper's fuel map is programmed to provide the correct amount of fuel via injectors spraying at 60 PSI, if the pressure is jacked up to 90 PSI the wideband sees that you are rich and faster than you can even detect it audibly lowers the duty cycle to inject the correct amount of fuel. In this short video you learn to replace the IAC. I watched the butterflies start to open at about 35 on TPS. 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. At this time, TPS is 0%, IAC is 50 to 60%. Those don't impact the way the engine runs and can cause the whistle sound you describe. 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. 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. TP range is normal goes up to about 90% with throttle pedal to the floor. Featured Products EFI - Fuel Injection $2.59 - $6,499.95 2179 Products View Parts Sensors The problem I'm having is I cant get the IAC to drop down off 100%. I think you will find that it will learn its way through this. Glad to hear that things are working well! Bolt-on carburetor style EFI for your classic car or truck. I did change the -40 thing also. I haven't driven it for the 30-40 minutes like the several times it idled at 2200. This only happens when coming to a stop and the idle is ramping down to the set idle RPM. The "PC Text" indicates what will be shown on the PC/Laptop data monitor or data logger. 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. Nice to meet you. I will let you know what the results are. So something is triggering the ECU to be in Open Loop. You can disable the idle spark control at the locations below. This can cause the engine to run rough and may even lead to engine damage. However based on your reply I connected the Fuel Pressure gauge and You could go either way.. Sniper EFI Idle Tuning. I can get it to fire up on the Turning it off and back on would reset it, and then it would work as advertised for a while. However, it is a good question so I thought I'd throw a few bits of info out there that I think might help.First, I believe that you may have a basic misunderstanding of what is being referred to sort of generically as AFR. We are running a Sniper on my mates 355ci small block V8 & so far he is very impressed ! Copyright 2022 Holley Performance Products, Inc. All right reserved. 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. Should I just disable idle timing control? Definitely would have went with you guys. I've been having problems with my sniper efi just shutting off. At low levels RF interference will often reset the ECU so quickly that the engine will not stall. It could be a problem with the power/ground for the Sniper but much more commonly this is a result of too much RFI. This is Intermittent meaning, I can run this test 5 times and IAC will function incorrectly 2 out of the 5 times. I followed the instructions and set the IAC to 2-9% when warm with idle at 850 RPM. After speaking with Holley Tech Support and Tech Support from where I purchased the systemthey decided to replace it. Only show this user . I installed the Holley gauge you suggested in another thread at the fuel input to the TBI, and the fuel pressure is constant around 64 according to the gauge. I have seen a couple of videos on you tube of the same issue but they don't seem to have found the cure.I hope it is not a computer problem as I have already replaced the entire system because of another problem. Keep in mind that at 60 miles the 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. 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. I did buy the Sniper from you guys and the service was fantastic. Hi Chris. Start with the most gradual throttle input you need to launch well, then slightly increase until you feel some stumble. The link above includes the option to buy a -6 AN If that tested out okay then I can really guess that there might be some sort of intermittent, temporary RFI. Yes it is controlling the timing and I had issues at first and it controlled the idle just fine. I know this is old, but I bought and installed a Sniper kit in 9/18. These aren't generic newsletters either but instead personalized emails. itself out and hold idleeventually stalling. Target AFR at idle is 13.8%. Is there any chance that your timing has changed since you installed your Sniper? Holley Sniper Iac Delete I recently had IAC issues identical to what you describe. If you look down and your TPS is 2% then either your throttle is stuck slightly open (which itself will cause the idle-up) or RFI riding on the TPS signal has caused the ECU to see the throttle as open and, as a result, open the IAC to the hold position. ChrisI finally got everything resolved. Sniper EFI offers superior throttle response and wide-open throttle power. It is made by one of the biggest names in fuel filters and sold under the Parts Master label so it is quality and great price in one. Do I have to hook up sniper ac wire to relay or should iac pick up idle? I cut and heat-shrink wrapped the 5V wire and then ran both the signal and ground wires all the way back to the transmission controller. The 10 step set up on your page set my idle perfect and iac perfect a very consitant 700. 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. If you find that adding 5-10 degrees of advance helps then it's time to do reconfirm TDC. Note that Brazilian gasoline has 27% ethyl alcohol. So what--you're never going to drive in minus 40 degrees, right? MAP Sensor. 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 didn't find your site until I was having trouble. To figure this out it's going to be important to gather a bit more data. It starts cold fine, its just when its hot. The noise is definitely coming OUT of the throttle body. *Possible delays due to Covid-19 click for more information. 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. Stupid question, but where do I see if it's entering Learn mode? Now it's at 5% on a big cam 440 Mopar. 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. Is there away to program the ecu to compensate for this at start up. You should get a light spray evenly distributed in all four barrels. A few, however, get tangled up getting the idle control working just the way they want. 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. I hope everyone enjoys this v. That way you can get into that part of the table that needs tuning, and you can watch your learn numbers grow. Remove the tape from the IAC breather hole and restart the engine. Ok, so there are a couple peculiar things going on here. I'm happy to walk you through what is required. Fortunately, I have an article that goes into this in some detail. What might cause the TPS to go to 2%? Learning to install these is great--you're about to embark on the next great adventure of advanced troubleshooting. I have not heard of this. Ive played with the timing on this thing multiple times.Car was fullly restored last year. My issue is that the TP% will not reset with key cycle and its idleing at 9% TP. :-)Yes, learn impacts idle too, and remember the even when the basic learning is done there will continue to be some learning for changes in weather, altitude, etc.Go ahead and try a few idle settings and see how they impact the idle-speed searching. You'll be amazed at how much of this just "goes away" when you drive it enough. The solution is to either lower the IAC hold position or increase the RPM above idle to start ramp (default is 1000 RPM). All times are GMT-6. idle counts from 0. Please help. I believe because the TPS is not registering. Will restart but only for a minute or so a couple of times then shuts down fuel delivery and will not restart. I very pleased with the performance, it is a huge improvement from the 800CFM carb I had on this motor. 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. 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. I'll bet you find that you can get it working great without any manual tuning. If you can send a data log to the vendor from who you bought your Sniper EFI System they should be willing and able to take a look and recognize RFI and then give you some ideas on solving it. Follow this link to download it for free if you have not already done so. I.e. Fortunately, these are much easier to solve. 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. When I put it in park the idle RPM was 2100-2200 each time. I would only play with this if you are finding that the other adjustments I suggested aren't working. What could be the cause? You will have to do this until the TPS stays at 0% when the throttle is closed. If One of the signs of a vehicle with a rough idle is a faulty Idle Air Control (IAC) Motor. You're going to have to get this fixed or it's going to cause even more problems than the high idle. When this occurs, I sometimes can shut it down and it will return to the correct settiings. But if you can datalog the bog you can know much more precisely what is happening. 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. That is the only way to fly. That 60% (which is configurable) is known as the Clear Flood TPS. The IAC should display a 2-8% to bring the idle up to the actual target. When I drive with warm engine the IAC is at 30% when pushing gas, but shouldn't it be at 0%? Reply Quote. Thanks. The first thing I'd do is check your fuel pressure with a gauge like this. such high fuel pressure. Closed Loop Compensation rises to 100%, Do I just keep pushing it the same way to I got it home, checked it all over, everything is hooked up correctly. By the way, this is a new installation on a 69 Camaro, stock 350, dual sync, etc. Yes, having an accurate TPS is very important at idle. I'm thinking it could be the fuel pressure--- since I have a new Spectra EFI tank and there's been some reports of the interior coating coming off and gumming up the pump however the sniper display DOES NOT show fuel pressure.the Sniper DOES measure fuel pressure on its own - i've confirmed that with holley techs as they told me to purchase the fuel pressure gauge that can just hook up to the 1 wire gauge harness from the Sniper. i'm having is I can't seem to get the truck to run faster than 45 mph at speeds Capability Range: Moderate 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 changed my roc/tps to 7 from 15 but that only took me out of learn mode. Enjoy! When you experience this, before you touch anything or shut the engine down, first look at your TPS and your IAC. Short drives is fine then it'll EFI parts, including the throttle body, and the problem persists.Please give me a hand. That is not a huge problem but it just means the IAC has no ability to lower the idle beyond what it is running at that point. 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. The idle is 1350-1400 with the idle screw at initial contact. So the issue Im having is low idle. Second, Holley just released over the weekend a video on how to implement a flex fuel sensor on their HP and Dominator ECU's. IAC is good 0-5% most of the time. I am at the point where I almost insist that every Sniper EFI System owner purchase one of these. It is reliant on the data acquired by the included wideband oxygen sensor. That will at least tell you something. The AFR was pretty consistent around 13. Properly configured, the Sniper does a fantastic job of responding to the transition from Park to Drive. You can drop it down and you will find it will behave more like you expect. One of the best Ive seen so far. And your understanding of how the throttle position affects idle is exactly correct. 90% of time with engine hot. 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. I'm wonder if the iac can cause this. 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! I'd really appreciate some help. And, while that is happening, make a note of the temperature before you engage the starter, and then the rpm when it starts.The Idle Parked Position is set on a temperature-based graph like the Idle Speed Curve. Holley Sniper IAC Surging???? This may require shortening or lengthening a rod. Be sure to re-enable it once you get your idle tuned. Throttle Tip-In puts you in a part of the fuel map where you stay for only milliseconds at a time. 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. We offer some tips to help with that. A couple of possibilities that come to mind in order of likelihood: Im having an issue with what I think is the Iac. But another thing to consider is adjusting your target A/F ratio. 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. I set it exactly like the instructions said and my iac is not only all over the place but when I finally did get it to the 2-10 range it's highlighted in red. If you datalog the Sniper ECU and see multiple overlapping traces for the same signal, you likely have RF-induced problems. So, this is what it takes to put a Sniper on a small-block Ford.