Of the two options, I generally recommend the self-learn. Hi Chris. Copyright 2022 Holley Performance Products, Inc. All right reserved. With the engine still idling high park, set the brake, open the hood, and remove the air cleaner. The 10 step set up on your page set my idle perfect and iac perfect a very consitant 700. Thank you. Ilike a few othersam having idle issues. 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. Also its extremely rich at idle. If your RPM is 2000, your TPS is 0, and your IAC is not closing, then there is some problem. I am right back to where I started. Thanks for any info./insight you can provide, Mark. holley efi. Cycled the ignition off. Not to bandstand here but this is the point when where you bought your system is so important. It is simply for the benefit of the user. We've already tried adjusting the Acceleration Enrichment chart in all ways, going up and down, RoC Blanking, everything, it has no effect. All EFI systems need a large fuel filter to trap dirt and yet not reduce volume. In that case, and if you have an EGR valve, I might be suspicious of something going on there. me know how it works for you. Simply turn the idle speed screw on the linkage in until the throttle plates open enough for the idle to increase. Setup: 1965 Impala SS; ZZ6 Crate Engine, EFI Distributor. idle counts from 0. I' m going to put the 3rd new pump this coming friday. Ive had an idle at neutral as high as 2400 rpm. I then saw you guys have an awesome little gauge that can hookup inline to the snipers existing fuel feed?? Car was running great initially. 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 We're never going to fill up your email box with nonsense. 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. If you go too high then the motor will not return to your target idle when you come off the throttle. It sounds a little different from mine, since it commands a 1300 or so increase intermittently. 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. I have been able to get it pretty Thanks for sharing that, Jason--great info! I'm Having trouble with the Sniper on high Idle. I am Japanese who attached Sniper EFI. When I put it in park the idle RPM was 2100-2200 each time. It's hard to know what the previous owner did right versus wrong. This curve runs fom -40 degrees to 260 degrees, and gradually reduces the RPM along that range. 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. Supports up to 650hp with Four 100 Lb/Hr Injectors! A couple of possibilities that come to mind in order of likelihood: Im having an issue with what I think is the Iac. Have you ever experienced a high idle once the engine reaches 200 degrees?Ive set my idle the way you said and it works great until the engine reaches 200 degrees. )If you rule out a fuel supply issue then we're going to have to gather a few more clues. But nothing beats a good solid gut-check I've been messing around for a bit trying to eliminate any possible vacuum leaks. 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. The IAC is hanging open and not really at 0. 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. But if the idle is a little bit higher then it doesn't have to jump quite as much in response to the load, and tends to react a little bit more smoothly. I have a Holley Sniper for almost 11 month now and it was running fine with no problems until now. That could be a problem with the TPS or it could be some sort of throttle linkage issue. 30 minutes later CTS reads 161, start engine Idle is jumping from 450 (almost stall) to 1500, IAC is jumping all over 10 90. This page was generated at 12:25 AM. It sounds a little different from mine, since it commands a 1300 or so increase intermittently. It is temperature dependent but 30 is commonly where you find it. The "PC Text" indicates what will be shown on the PC/Laptop data monitor or data logger. If you use your handheld to go here: I was 20 minutes into a drive yesterday when all of the sudden the RPM increased not commanded. I recently bought the car with the EFI system on it. Your issues are likely related to one of these two things. Does this seem reasonable and how hard will it be to get the idle and off-idle performance correct? Holly offers a very nice Analog-Style Fuel Pressure Gauge that is another option. it will jerk and rpm will go up and down and AFR will be around 20 : 1 or more or less. However, I always preach to never touch any of the controls on the handheld until you have a couple hundred miles on the engine in a range of driving situations. 34K views 1 year ago Holley Sniper How to Set The IAC Idle air Control in 5 minutes or less. Inj. 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. Therefore The iac will always be at 10% now, correct? You will need to change the -40 degree idle speed setting again but I recommend not touching anything else. Good luck! 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. The engine ran so good, I would have never suspected the Fuel Pressure to be an No timing control, coil negative ignition type. What should I be looking at to calm this down? In the context of the Sniper the AFR that is being displayed is the AFR of ethanol-free gasoline based on the lambda that is being read by the AFR. Hi I wish I had bought from you but I didn't find this site until now. It started right up and we did your idle control fix and all is good at idle. If you remove the air cleaner entirely and the whistle continues then you can rule that out. No air should be able to pass. No power at the programmer and no fuel pump running. I would recommend that you call first thing in the morning, as they tend to get quite busy during the day and wait times can get long. In the Wizard, select the stock cam setting. Remember that as an EFI System Pro customer you have access to me at any time via my cell phone. Otherwise, if removing the air cleaner eliminates the whistle then try to use a thicker gasket or try lightly greasing the gasket. After a complete cool down it will do the same thing. Will restart but only for a minute or so a couple of times then shuts down fuel delivery and will not restart. Your closed loop compensation is adding a full 50% fuel. Usually it wont stay on 0% very long and soon changes to another number like 1 or 2%. Its rare that you find someone that genuinely wants to help and see something work good, the information I have received from this page and Chris himself is top notch.1969 Dart GT 340 with a Holley Sniper, I purchased the Holley sniper from jegs wish I knew you sold them put on my truck got the IAC set haven't checked the -40 idle setting yet my problem is my headers are glowing red called Holley I think I got the worst person seemed to care less Afr is set at 12.8 for idle only thing I have changed I don't smell any fumes at idle someone said I could change the coolant temp enrichment but I don't know if it is rich or lean I figured since no smell it is lean any ideas would be appreciated thanks i have a fuel psi gauge reads 60 psi don't wanna melt my motor did not glow with a carburetor. Also if I give it a Get On The List for Emails Straight From Our Pro? check out the. Is this an issue to worry about? 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. Rpm with 4-8 iac but it still shows red and shuts off randomly at idle and it won't even drive 2 miles without shutting off. Cl. The weather in Ct has finally improved and I have put about 60 miles on the car with the Sniper system. So something is triggering the ECU to be in Open Loop. Tps is saying 26% when it at idle. 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. Idle when warm was 850-ish and IAC 3-4 just as when I readjusted it the night before. I appreciate everything you are saying. What an amazing site you have here. Let me start with the engine not starting until you press the throttle. I have never seen issue when CTS is below 120 degrees. 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. What I can't explain is why your TPS is acting so randomly. Holley Sniper Iac Delete I would continue checking the electrical connections along the fuel supply. If you drop it too far the engine will stumble or stall when coming off the throttle with the car out of gear, so you'll know when you've gone too far. The problem I experience is that after driving for about 10-15 minutes, the car starts idle to high. It won't take much! Have you confirmed your fuel pressure at idle is 60 PSI? I'm new to the efi thing and any help would be seriously appreciated. One additional wrap on the secondary coiled shaft spring is all that's necessary. Initial Baseline Idle Speed Screw Setting, http://forums.holley.com/showthread.neral-IAC-Info, http://documents.holley.com/199r11031r.pdf, https://forums.holley.com/showthread-Idle-Solution, If this is your first visit, be sure to Data logs show no EMI/RFI. have the system learn the higher speeds? 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. If it is not a problem with the Sniper EFI System itself then it could be an issue with some sort of harmonic involving the fuel pump. The Sniper EFI system looks at the closed-loop fuel compensation required to reach your target AFR. IAC looks good once it finally s fires. 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. (If you do this you will need to reset the -40 degree setting mentioned at the top of this article. You will have to do this until the TPS stays at 0% when the throttle is closed. Throttle Tip-In puts you in a part of the fuel map where you stay for only milliseconds at a time. Laptop Access I'm going to jump out on a limb here and say you either don't have adequate fuel flow or pressure. I go into much more detail about that in this article on startup tuning. Thank you. My car will now start when its cold, but after about 30 seconds the idle drops down and begins to run like crap. If you do find you have RFI issues then I've written an . Technically it is a warranty-voiding maneuver so proceed at your own risk. However, I can't think of a single one that was because of low vacuum. You'll be amazed at how much of this just "goes away" when you drive it enough. Repeat until that stumble goes away, and then try a bit more throttle. Comp. Ok, so I'm stumped! This page was generated at 12:25 AM. The timing can drift 0-30 degrees just due to the width of the rotor tip. Though they both are indications of the amount of opening through the throttle body, the TPS is the throttle opening percentage and the IAC number tells us how far the IAC stepper motor is opening the bypass air circuit.If I understand you correctly you are saying that the TPS reads somewhat normally (traveling from 9% to 100% or so) but that when you cycle the key it once again starts at 9%. May God's grace bless you in the Lord Jesus Christ. We are using Target AFR of 9.0: 1, Fuel Base approximately 40% higher. Ive played with the timing on this thing multiple times.Car was fullly restored last year. (Do this while you are cranking.) Once you know that then you can work on those problems. 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! Hey Chris I have one customer who is having some similar issues and his AFR is down at 9.6:1 when it won't start. Get that thing installed and you're going to know a whole lot more about what's going on. This will let you know at a glance if something is going awry with the fuel pump. You can find those settings here: Handheld: Tuning > Advanced > Advanced Idle > Rampdown, Software: Idle > IAC Settings > IAC Ramp Down. The last 2 times have been shorter and one time the high idle was around 1400, this time around 1100. 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. I very pleased with the performance, it is a huge improvement from the 800CFM carb I had on this motor. Wish I knew about it before I made my purchase. You're going to have to get this fixed or it's going to cause even more problems than the high idle. My car will not idle right until it gets to around 130 -140 degrees. One way is to very carefully watch the handheld monitor, and that may be adequate. Cheers Darren. Follow this link to download it for free if you have not already done so. Fortunately, I have an article that goes into this in some detail. It might be necessary to insulate or re-route your fuel lines if this can't be solved any other way. I'll bet you find that you can get it working great without any manual tuning. around 45 mph it bogs down, catches itself, bogs, catches, bogs and catches. That's a nice change of pace--a low idle issue! Hello Chris. !I called Holley today, and before I could even described the symptoms the I am having an idle issue (other than that is absolutely perfect). Remove the tape from the IAC breather hole and restart the engine. Clearly, something is changing. Your AFR is pegged lean. mail today. The idle will not return to the set value.The second issue is the same as the first but the motor will stall out. The only other thing I changed was accel enrich but whatever way I go doesn't seem to change anything unless I change it drastically. Commanding the engine to automatically increase speed when switching into drive is a little scary to me though. Start engine let it warm up to 160, learn mode is learning. Fought a high idle issue until I changed your idle speed curve fix along with dropping the IAC hold to 10%. In the time it takes to add your email address you can be at the top of the heap for getting the latest information from our authority. The link above includes the option to buy a -6 AN The fact that it ran so (at times) with 90+ PSI fuel pressure is a testimony to the Holley's closed-loop technology. If you go too low then it may stumble or even stall when coming off of throttle. When I turn the key on I can hear it prime, but I don't think im getting enough fuel. And your understanding of how the throttle position affects idle is exactly correct. If I cruise down the road at lets say 60 mph and lay into it, she will take off and go. But as you see from the recent revision I did above you seem to be having a fixable issue. Somehow air is entering the engine that was not entering the engine when you originally set the idle speed screw. Can the return line be an issue?I have had 2 faulty gpa-4 255 walbro pumps go bad. After the start process, If the idle speed is higher than the target idle then the IAC should begin closing as long as the TPS is below 2%. Glad to hear that things are working well! Let 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. This may require shortening or lengthening a rod. 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. Yes, it will talk to you--but not with words. When I drive with warm engine the IAC is at 30% when pushing gas, but shouldn't it be at 0%? I took some pics of the sensors page this morning after the car warmed up. I think that the more important point is that Holley kept sending him units until everything was working. 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. Honestly, I've never seen this happen but if the butterflies were misaligned on the shafts it could allow too much air to enter. The motor has 376hp at flywheel and the car is a stick shift. If I read it correctly, the solution from the other thread seemed to fix a constant 300 or so RPM increase. I would disregard any correlation between idle control between the Stock and Street/Strip setups. Lubricate the linkage so there isn't as much native resistance. He said they have been having an issue with these lately. It's not necessary to drive it that way. The "Gauge Text" is what would be shown on a 2-1/16 gauge or the Avenger handheld display. 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. About two minutes after I get it set at 850 & 5%, it has progressed to 100%. Kind of cuts into forum time. 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. I know its not flooded because I can pour a little gas in the throttle body and play with the accelerator and it will start and run fine. Really appreciate the amount of learning im getting off here. NOTE: Do not attempt to set the target idle speed and IAC position until the engine is above 160F! first attempt but as it tries to idle down to the target RPMsit can never even It works instantly for him.If that fixes your problem then you have a starting place. Could the IAC be broken/malfunctioning? We do that but most places don't. Sniper EFI Idle Tuning. The IAC reads 36 when at idle fully warmed up. Your mechanical advance will naturally change the timing a bit but it should be fairly close. Good afternoon Chris, thanks for taking the time to help all of these folks that didn't purchase from you- myself included!The issue I seem to be having is at idle in both park/neutral and drive. When you open your IAC to 30% you are naturally going to have a high idle condition. This page was generated at 12:26 AM. (Plus they it just looks way cool in your engine compartment!) Ensure there isn't a vacuum leak causing the IAC Position to drop to 0%. Take a drive and stop somewhere for 30 minutes, CTS is 170 when engine was shutoff. Is there away to program the ecu to compensate for this at start up. you have it set. Eventually the IAC will drop back to zero, I'll readjust it to 850 RPM & 2-9%, and then watch it steadily climb again. Pw. 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%. 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. Do you have any clue? Copyright 2017 Cyberspace Automotive Performance, Inc. All Rights Reserved. The idle is 1350-1400 with the idle screw at initial contact. Is there away to lean the idle out? 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. 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? 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. And, hopefully, within those degrees you will find a place where you don't get the whistle. If that happens then follow my 10-step process shown above. >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. )Since this isn't a consistent issue with all Snipers that tells me that different IAC settings tend to make the whistle. 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. If this is the case then some adjustment of the linkage or the butterfly plates themselves is necessary. Again, I would lean on that solution to let the vehicle drive/learn before you try to "fix" anything. Thanks for any help. It could be a problem with the power/ground for the Sniper but much more commonly this is a result of too much RFI. Definitely would have went with you guys. If your TPS has snuck up to 2% then your IAC will be at the hold position, which by default is 30%. I managed to get the IAC down to around 0% - 8%is this good? For someone in your position, it will become an indispensable tool in your tool box. 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. Hi. But, if the idle is so high that it is making you crazy then you might try dropping that number just a bit. If you set the RPM above idle to start ramp too high, then it may not ever get down to the RPM above idle to re-enable. The next time it happens is the perfect opportunity to find the problem. ?I never had my Carb Cold start RPM any higher then 1600 RPM.THANK YOU. Any idea's? I believe that for the HyperSpark the Reference Angle should be 57.5. Holley Sniper IAC Surging???? Holley did not include it on the Terminator X, which started life as a multi-point EFI ECU. Bolt on 4150 Flange Carburetor Replacement. Worst case you'll have a spare on hand, and if the TPS is faulty you will have solved the mystery. Fuel Flow lb / h = 12.1 But there are several degrees of play there in which it should still work fine. I had this same exact issue. As soon as I got the new one installed and wiredit fired right up and did everything it was suppose to do with no issues. Yes, it will talk to you--but not with words. I will try the other stuff when I get off work. Start with the most gradual throttle input you need to launch well, then slightly increase until you feel some stumble. Anyway I have a 327 sbc in a 1987 Monte SS with a T5 5 speed and 3:73 posi rear.
holley sniper efi iac problems