The noise is definitely coming OUT of the throttle body. back upthe RPMs shoot up to anywhere between 1500 and 2000 and they will not get Good luck! It is a common one. other things that might cause the idle to faulter, but this is a good start. I called support line he said he would have to look into it and call back. Hi Chris , greetings from Down Under (AUS) Just a note on the hi fuel pressure issue . There's a procedure there I can share with you if you'd like.. Also what would you say a desired idle should be for a 3 speed automatic ford? Chris, I recently installed my Sniper and have an intermittent idle problem. As far as the timing light, I don't know, because I was having problems getting it to work, and that's where I stopped. I have never seen issue when CTS is below 120 degrees. Sniper EFI Idle Tuning. Well you were right air was entering from another source. Note that sometimes you can get into a back-and-forth situation. Wish I knew about it before I made my purchase. Follow this link to download it for free if you have not already done so. That is what I really respect about Holley. to. I think that this time around you will find that it starts and idles really well and only gets better from there. If i set the idle to 750, the only way i can get it there is to turn the idle screw all the way out but then its at 0 iac. Advanced throttle body injection systems capable of transmission control and more. Target AFR at idle is 13.8%. There is no sense proceeding until your TPS is at zero at key-on. any advise would be appreciated. That is the only way to fly. Do you have any clue? Once it decides to come back down, it does so with no issue. P.S. At low levels RF interference will often reset the ECU so quickly that the engine will not stall. Doesn't want to start, runs like crap. Enjoy your Sniper! Possibly cap, rotor, coil? Idle Tuning is a very important part of tuning any EFI system, especially our self-learning units like Sniper or Terminator X EFI. I think that your Sniper system is working fine but would definitely check ouf the fuel pump. Then, the next time I cranked it, the idle went high and won't come down!" Any suggestions? It is probably that your RPM above the maximum point at which ramp-down can occur. The link above includes the option to buy a -6 AN 400 engine, C6 3 speed automatic, with standard canister coil for ignition, and You are aware of the idle-up problem. All times are GMT-6. Not that I noticed. But you've got to find where air is getting into your engine.The reason it's going up as high as 2400 RPM is because once you press the throttle beyond 1% the IAC opens to the park position. I got it home, checked it all over, everything is hooked up correctly. I've read that a spacer with 4 individual holes will solve this, but after I installed the progressive linkage the noise went away!! A problem since day 1 - YouTube Leave a comment if you've had this issue and how you resolved. I'm wonder if the iac can cause this. The fix? Every time though I can turn the car off and restart and it settles at 850 with IAC 2-4.The thing that has me puzzled is how the with the only difference in condition of the car being the restart, the idle is "fixed"Any clues on where to look next please let me know. In most cases the IAC (Idle Air Control) circuit is the source of the whistle. Somehow air is entering the engine that was not entering the engine when you originally set the idle speed screw. you have it set. If your RPM is 2000, your TPS is 0, and your IAC is not closing, then there is some problem. When this occurs, I sometimes can shut it down and it will return to the correct settiings. If I read it correctly, the solution from the other thread seemed to fix a constant 300 or so RPM increase. would correct it (as it has for a multitude of other drive-ability issues) but this one little glitch seems out of it's range. Contact whomever sold you your system or Holley directly. Once you've done this, the next natural step is to transfer the learn table to the base map, then go in and smooth out the sharp edges, which are going to be at these transitional states. Can the return line be an issue?So far this sounds like an ideal setup.>I have had 2 faulty gpa-4 255 walbro pumps go bad. In that case, and if you have an EGR valve, I might be suspicious of something going on there. One way is to very carefully watch the handheld monitor, and that may be adequate. So what--you're never going to drive in minus 40 degrees, right? Capability Range: Advanced I have a set of 8.8 Accel Rfi suppression wires on it. When I start the motor I have to push on the accelerator pedal for the motor to start. 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. Or alternator? 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 set the AFR at 13.5 and all is good now. check out the. Take it a step at a time. Hello Chris. With select intake manifolds, the distributor housing and IAC valve on the back of the Sniper EFI throttle body are fighting for the same . Until the engine starts, the throttle only has one purpose: To detect you pressing it to 60%, at which point it shuts off the fuel injectors. 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. I received from the controller manufacturer greatly understates (at best) the repeated failures of others I know personally who have tried and failed. THANK YOU for the "First--Check Your Idle Speed Curve Setting!" I had a customer recently with a high idle problem that he eventually traced to pad plug on one of the vacuum ports. Not to bandstand here but this is the point when where you bought your system is so important. Don't make any changes more than about 10% and keep the same basic shape as the original (High/flat below 20 degrees, sloped downward up to 180 degress, and then flat again above that.) 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. I'd recommend you contact Holley Tech support to get their input (1-866-464-6553; call early for the shortest wait times.) Duration @.050 is 240 intake 246 exhaust with .574/.578 lift. Shutoff engine wait 30 seconds, turn key wait for display to come up, start engine. Also when ac kicks on it will idle down and stall. I pulled over and turned the car off and then back on. Technically it is a warranty-voiding maneuver so proceed at your own risk. 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. Remember that as an EFI System Pro customer you have access to me at any time via my cell phone. Start engine let it warm up to 160, learn mode is learning. The answer will divide the possible sources of additional air into two, greatly simplifying the problem.If the IAC number has not increased, then review the article above regarding high idle from a vacuum leak or high idle from sticking linkage. You might even want to add our 4-foot extension harness that will allow you to connect/disconnect the display or CAN-to-USB adapter from inside the car (rather than trying to do that leaning over the engine and under the breather. It might be necessary to insulate or re-route your fuel lines if this can't be solved any other way. Are these compatible enough? Once you have done this the challenge is to create a datalog that includes the ":snap" you describe. The Tech Tips and discussions are also great! Only show this user . In this short video you learn to replace the IAC. The noise changes sound with the throttle position. I started with right after I first adjusted for 2% IAC and took pics about every 30 seconds over about 2 minutes. To be honest, you sound like an ideal candidate for Sniper ECU ignition timing control. 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 very pleased with the performance, it is a huge improvement from the 800CFM carb I had on this motor. It has gotten a little better after I drove it for three hours today.I want to save the Kik because if I get this working good then I would like to add A C and use the kick for it.Motor is Mopar 360 with mild cam and automatic. It's not necessary to drive it that way. Running new vintage air system so the is only a single power wire to compressor thats why I asked if I needed to run input wire to ac relay or if iac would pick it up fast enough(which its not). 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. Holley documentation and videos didn't work and the $300 I paid for "expert" tuning didn't work either. Please advise. Capability Range: Advanced If you've been running a filter then you have to wonder if you have a legitimate Walbro pump.If you install a new pump and the noise is still coming from the Sniper EFI System then only the dealer who sold you your system can help you. I think you'll be all set! You can drop it down and you will find it will behave more like you expect. I enalble the idle timing control and fired it back up Iac was at 32% but it would come back down after a bit to around 26%. 90% of problems, (INCLUDING MYSELF) could be answered/fixed by just reading the instructions. Thank you. If I'm driving along and pull up to a light and leave it in gear it idles just fine but it seems not to be able to compensate if I put it in neutral and then back and drive. When I first told him to check for leaks he looked back there and said "all good". Then it changes and will not idle down, the handheld will display 0% IAC but you can see and feel that the IAC valve is more like 100%. Shut off car/restart and it's back to idle at During after-start idle, the idle will jump up to about 70% if the engine is cold, stay there about 4 seconds and then ramp down to the target idle speed for the current engine temperature. 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 your TPS has snuck up to 2% then your IAC will be at the hold position, which by default is 30%. Thank you chris for for getting back to me on this matter.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. 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%. 3 different fuel pumps. Has a good size camshaft cant find any vacuum leaks. 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!) Then you can take a close look at the IAC and see if it is opening. However, whenever you start changing things, you can get into a chain reaction. Its on a big block Mopar with stock electronic ignition . At that point, with 90 PSI of fuel, the ECU can't turn the duty cycle down low enough to idle properly. TPS% = 1 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. Note: The IAC breather hole is the roughly 1/4-inch triangular hole that sits above and between the secondaries. If the TPS reading on your Sniper EFI System does not reset to zero that is a problem that needs to be addressed. I had that problem, right out of the box it would not power up, sent it back in, had defective hand held. They are prone to be inaccurate. I've increased the IAC rampdown time to 8 seconds to try to combat this, but wondering if it will correct itself over time or if I need to possibly replace this TP sensor. I'll give the ". All of the wiring exits below the rear fuel injector cover, for a completely stealth installation. Cycled the ignition off. With everything else being right and since you can make it start by adding fuel it seems like you must have some sort of fuel pressure issue. IAC Pos.% = 0 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. That's not the IAC Hold Position, it's a percentage value. So you installed your Holley Sniper. ps. Your closed loop compensation is adding a full 50% fuel. If the engine will after the 4 seconds that the IAC kick drops off then it's not really going to help.At any rate, it costs you nothing to advance the ignition and see if that doesn't improve the idle, right? close to idle with the IAC between 2% & 12%. If more info is needed just ask. (Grease can sometimes do the same thing as a more permanent gasket sealer without making the removal of the air cleaner such a pain.). If the TPS is 1% or below then the air is coming from somewhere else. Did your process to adjust idle to 860. You might have a bad IAC, but you can also have a bad vacuum pod on the transmission. Also its extremely rich at idle. Thanks for the info Chris. Holley Sniper IAC Surging???? A couple of those and you should feel it getting better. There is a chance that the IAC is open but displaying 0% so start by putting your finger over the IAC opening. ?I never had my Carb Cold start RPM any higher then 1600 RPM.THANK YOU. The headache is the Acceleration Enrichment. Genuine Walbro fuel pumps are virtually bullet-proof. Im thinking a faulty TPS. A good example of why it's so important to run a good pre filter in the fuel line. 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. I have tried your 10-step idle adjust and ive adjusted the idle curve. If so remove it. No timing control, coil negative ignition type. Seems to behave more better now. Its just at low speeds, not sure if its loading up or leaning out. I notice at 2-3% tps the iac is 18-25% and it stumbles, when the iac gets to my hold position of 30 it stops. This can cause the engine to run rough and may even lead to engine damage. An undersized or partially plugged fuel filter is a classic EFI installation mistake. Two things to keep in mind as you do 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. Using a Snap-on variable timing light so this is why I say timing is perfect. 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. It is reliant on the data acquired by the included wideband oxygen sensor. Let me be perfectly clear: If your engine will not drop below 1350 RPM with the idle speed screw turned all the way out then you have an air leak. Is there away to program the ecu to compensate for this at start up. Keep in mind that at 60 miles the A few, however, get tangled up getting the idle control working just the way they want. I think I figured some of my problems outI'll try to explain. But he kept having problems so eventually he did a complete check and then he found the problem. That is the IAC hold position. But they are 100% committed to your satisfaction. :-DStill, I hate to leave someone hanging so I'll try to help. You can disable the idle spark control at the locations below. So check that timing and I think that you're going to find you need a good bit of advance. So something is triggering the ECU to be in Open Loop. Note that Brazilian gasoline has 27% ethyl alcohol. I tried adjusting my IAC up to 10deg in both directions with no change. You just need to go back through the IAC adjustment procedure now that idle timing control is enabled. This is Intermittent meaning, I can run this test 5 times and IAC will function incorrectly 2 out of the 5 times. The Sniper will be controlling the timing so it will be based on a multitude of factors. The team at EFI pro are some of the best I have ever dealt with when coming to ordering parts or having the knowledge to answer any question you may have. back to trying to zero down an idle. 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. However, I have never found that to be the case. During cruising at 30 miles and release the gas pedal the engine revs at aproximaly 1500 RPM and it won't drop. It appears that I could now use the dongle and a laptop to custom tune for idle issues if needed. If that tested out okay then I can really guess that there might be some sort of intermittent, temporary RFI. Sorry for all the questions, new to the efi world. Incorrect connections will result in excessive resistance. 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 I block off the iac with tape , I can get it to somewhat idle, but its not consistent. Well, it sounds to me like your Sniper is doing its best to reduce your idle. What I would recommend is getting somewhere that you can spend a significant amount of time doing starts. Your AFR is pegged lean. The jack-rabbit start can usually be minimized by adjusting the throttle linkage. Fortunately, these are much easier to solve. So I have been doing the slow take offs and thinking that it would learn its way out. I have quadruple checked my wiring and am certain it's correct. 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. 34K views 1 year ago Holley Sniper How to Set The IAC Idle air Control in 5 minutes or less. Then it will ramp down to 1200 but will not return to idle. Your suggestion to remove the PCV valve is just for diagnosis purposes, right? Since the shield was put on, not a single problem, not one. Note too that the larger the throttle stab, the more brief the time in that cell and the more gradual the change.Here's what I recommend: Get somewhere where you can repeatedly stop and go. Could you provide me with some things to check or some things to adjust? Chris, Also, I was seriously rich at idleso rich it hurt your eyes. 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. But after sitting static idling for a little bit, the IAC goes to 100% & stays there. It is temperature dependent but 30 is commonly where you find it. When you set the Static Timing to 15, what did you read with the timing light? 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. Once you confirm the operation of your IAC then it's time to read my article on Solving RFI Problems. The problem I experience is that after driving for about 10-15 minutes, the car starts idle to high. 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 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. mail today. Chris---I am contemplating replacing my Holley 750 on my new low vacuum 600 HP 496 with the Holley Sniper FI system. I have probably 200 - 300 miles on this engine and it has always done this. But as you see from the recent revision I did above you seem to be having a fixable issue. In the wizard I set my Idle to 500RPM but it never got slower than 800RPM, if I run the wizard again and lower to 400 RPM then it never gets lower than 700RPM.After reading about the Idle Speed curver I checked its settings and found that the curve was 300rpm faster at every point over the temp range no matter what temp I had, I adjusted the curve to match what I put in on the wizard and now the RPM is correct, I'd say you have a bug in the wizard.Idle Speed > Idle Speed Curve: Here is where the lack of coolant temperature is going to affect you. Purists will sniff that these are not accurate to the tenth of a PSI. I will be at a red light trying to brake against the engine. Throttle body mounted ECU - no extra boxes to mount. One of the most common symptoms of a Holley Sniper EFI problem is an air/fuel mixture that's too rich or too lean. Switch power to the Sniper on and crank the engine. It turns out that some of the Snipers are shipping with the minus 40-degree setting drastically lower, as shown in the following image. So the issue Im having is low idle. (Don't drive and watch--get a helper!) That is the default "Clear Flood" TPS setting and turns all fuel off until the engine cranks. I appreciate the help youve given to everyone as it continually helps me! This may require shortening or lengthening a rod. Fortunately, Holley has another product that can solve that: Hydramat.. Hydramat is not inexpensive but you won't believe what it can do. If the TPS is even just 2%, the IAC will go to the hold position (normally 30%) and will not change until the TPS goes back below 2%.If you create a datalog you will be better able to confirm if something is not working correctly. the gas it catches itself and runs fine at slower speeds. If i adjust the throttle plate screw in to bring IAC in to proper range say around 7 the engine is running around 2000 rpm. This page was generated at 12:25 AM. If you remove the air cleaner entirely and the whistle continues then you can rule that out. 30 minutes later CTS reads 161, start engine Idle is jumping from 450 (almost stall) to 1500, IAC is jumping all over 10 90. The Sniper EFI remote IAC (Idle Air Control) and plug is designed to gain installation clearance on some Sniper EFI 2x4 installations. I managed to get the IAC down to around 0% - 8%is this good? Target AFR, A / F = 13.5 You may have to register before you can post: click the register link above to proceed. When I put it in gear, it drops so low that it will stall if I don't add throttle. Yes, it will talk to you--but not with words. But another thing to consider is adjusting your target A/F ratio. Cheers Darren. RPM = 1200My slow gear I leave with 650 RPM, the IAC Position I leave between 5 and 6%, the The very first thing I would do is get ground truth on your timing. If I adjust idle screw out to get the tps to zero or even 1% the engine will not idle. Were the additional load a simple step function it would be challenge enough for the ECU to gracefully increase the engine speed without overshooting. 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. Check fuel pressure too (. )Since this isn't a consistent issue with all Snipers that tells me that different IAC settings tend to make the whistle. I would suggest you take a look at that if you haven't already. May God's grace bless you in the Lord Jesus Christ. Confirm the placement of all wiring, ensure that the WBO2 sensor is positioned properly, etc. We are running a Sniper on my mates 355ci small block V8 & so far he is very impressed ! I followed the instructions and set the IAC to 2-9% when warm with idle at 850 RPM. If idle drops below 800 it wont come back itll chug around 300 rpm for a few seconds then die. 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. Both answers you've received greatly oversimplify the truth in favor of the answerer. If you go the other way then you might find that the IAC zero's out when the fans are off. 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. Good Bolt-on carburetor style EFI for your classic car or truck. I recently bought the car with the EFI system on it. I'm Having trouble with the Sniper on high Idle. The warmer the motor, the higher the idle will be at this point. idle counts from 0. 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. issue. That is not the way to go. That disappears as soon as the throttle is pressed and then you immediately revert to your timing table.You can certainly use the compressor to initate the IAC Kick, but remember that this is just a temporary idle boost to ensure that the engine doesn't die when the AC is first turned on. Price Point: $, Advanced throttle body injection systems capable of transmission control and more. :-). The small rubber plug had a leak. For someone in your position, it will become an indispensable tool in your tool box. Turning it off and back on would reset it, and then it would work as advertised for a while. If you datalog the Sniper ECU and see multiple overlapping traces for the same signal, you likely have RF-induced problems. Ran 2 Holley carbs and an Edelbrock. 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. I don't want to go on too long here but once you know if you're trying to add or remove fuel, there are a couple of ways to go. You should get a light spray evenly distributed in all four barrels. I then saw you guys have an awesome little gauge that can hookup inline to the snipers existing fuel feed?? Seems like its too slow to grab idle when ac kicks on. Idle quality is great, RPM is good, sometimes IAC is jumping around from 35 to 60. Idle : IAC Rampdown : IAC hold positionChange this by maybe 2% in either direction. On startup- cold or hot, I get a 2 second high idle of about 1500 RPM before normal set idle of 750 RPM happens. The fuel pressure regulator in the Sniper is fairly simple and not prone to failure, as far as I know. That's what you're seeing. After 50 on the throttle position I'm not sure if the whistle goes away or you just can't here it anymore.