holley sniper efi iac problems holley sniper efi iac problems

I have checked the pink wire and it is at .001 volts when key is off. I've not heard of any others with this exact issue so I don't think it is a common problem. I installed a Holley Sniper on my Ford Maverick 302 V8. Copyright 2022 Holley Performance Products, Inc. All right reserved. 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. (Do this while you are cranking.) Fought a high idle issue until I changed your idle speed curve fix along with dropping the IAC hold to 10%. Give them a call and if they are unable to provide customer support the contact the Holley tech support line at 1-866-464-6553. Good I went on the good ole interweb and found your website which was VERY helpful! 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. % = 49 Hi Chris I didn't get any traction on Holley.com Sniper setting is Stock camshaft. When I turn the key on I can hear it prime, but I don't think im getting enough fuel. Always had to set idle above 950. 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. But nothing beats a good solid gut-check In this short video you learn to replace the IAC. Super helpful and knowledgeable. 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. Not good.There isn't set solution here that works for all engines. I've been messing around for a bit trying to eliminate any possible vacuum leaks. A good example of why it's so important to run a good pre filter in the fuel line. Make sure that your blanking level is _below_ that (being careful not to find yourself in the situation I describe above.) I have replaced the IAC motor and the problem remains. Sorry for all the questions, new to the efi world. Supports up to 650hp with Four 100 Lb/Hr Injectors! Also ensure the TPS Position returns to zero at idle, & the IAC Hold Position isn't setup too high. Shutoff engine wait 30 seconds, turn key wait for display to come up, start engine. Be aware that there is a spring behind there and a diaphragm that you don't want to tear. 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. to. If you find that the IAC is more than 8 percent, repeat this process and instead of shooting for 50 RPM below your target make it only 40 RPM below the target idle speed. check out the. When I covered the IAC with my finger, the RPM dropped so low it stalled. lower until I turn down the set screw. I would suspect something is coming loose causing a stop to the EFI system/Fuel flow. Check fuel pressure too (. I would continue checking the electrical connections along the fuel supply. Even then, recognize that over time the IAC will need to be readjusted to compensate for minor changes that will cause it to drift. You can find those settings here: Handheld: Tuning > Advanced > Advanced Idle > Rampdown, Software: Idle > IAC Settings > IAC Ramp Down. The throttle blade adjustment is at 2-6% at hot idle, and with warm engine 185F. I have been able to get it pretty Some have suggested mis-setting sets the idle speed at 850 RPM but I suspect it is not a fixed number but rather a delta of about 300 RPM above the target. The problem I experience is that after driving for about 10-15 minutes, the car starts idle to high. 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. 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. 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. How can I adjust the startup speed down to about 1400 RPM? Yes, you are correct. Your task will be to find that. If there's any run time on your current setup the Sniper may have some bad learn data due to what appears to be timing issues. These are "transitional" cells, and you really have to make the effort to learn in these areas of the map. In that case, and if you have an EGR valve, I might be suspicious of something going on there. We can not hit it at all, we hit the pedal abruptly, the engine gives a lot of excess fuel, the AFR gets super poor at first, the car stops, then the AFR gets super rich and the car runs until it cleans up. The engine makes very low vacuum at 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. It could be that you've left a vacuum port unplugged, it could be that the throttle plates are misaligned (unlikely), it could be that your IAC is not closing properly. I'd recommend you contact Holley Tech support to get their input (1-866-464-6553; call early for the shortest wait times.) Anyway I have a 327 sbc in a 1987 Monte SS with a T5 5 speed and 3:73 posi rear. I ask because I'm using a PCV valve with my Sniper and have random idle issues as well. Interesting situation you have. 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. Yes, having an accurate TPS is very important at idle. installing and cruising down the highway 70 mph I just wonder if all I have to do Perfectif you have the original synchronous linkage. The data that you provide shows that you have at least two problems. My car will not idle right until it gets to around 130 -140 degrees. 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 please let us know what you find out! TP range is normal goes up to about 90% with throttle pedal to the floor. It then idles up from 750 to 1100. other things that might cause the idle to faulter, but this is a good start. Engine warms up to 195 degrees and stays. My IAC and TPS show zero when it does this. Holley Sniper Iac Delete Your issues are likely related to one of these two things. 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. Learning to install these is great--you're about to embark on the next great adventure of advanced troubleshooting. issue. As I said I didn't buy from you so you don't owe me anything. Should the iac% fluctuate? Try it! Overview. 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 problem was RF interferance . At this time, TPS is 0%, IAC is 50 to 60%. Given the circumstances I would say that it is either the IAC motor itself or RFI but you seem to have ruled both of those out. 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. I have certainly seen this before on other fuel injected vehicles when hot. The resulting resistance can burn up fuel pumps, wiring and relays. the issue knowledge with the sniper efi setup. Ok, so there are a couple peculiar things going on here. In the datalog the engine is running at 1400 RPM, TPS is zero, IAC is zero, CTS is 185F but it's in Open Loop. Thank you for your input. Intermittent stalling usually points to radio frequency or electro-magnetic intereference (RFI/EMI). All times are GMT-6. Sniper EFI Tuning & Tech. 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. I have an adapter on the manifold for squarebore to spreadbore and then a phenolic spacer. I was 20 minutes into a drive yesterday when all of the sudden the RPM increased not commanded. Thanks for the great question! Without it you are working in the dark. The warmer the motor, the higher the idle will be at this point. If I read it correctly, the solution from the other thread seemed to fix a constant 300 or so RPM increase. Not that I noticed. If the TPS reading on your Sniper EFI System does not reset to zero that is a problem that needs to be addressed. I think that your Sniper system is working fine but would definitely check ouf the fuel pump. Inj. When you set the Static Timing to 15, what did you read with the timing light? 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. I will try the other stuff when I get off work. Using a Snap-on variable timing light so this is why I say timing is perfect. 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%. If I were there in person I would test the function of the IAC (see this article.) that my Air/Fuel ration was 15:1 and I believe the target is 13.5:1. Camshaft is M-6250-B303 .480 lift intake & exhaust, duration at .050 is 224 degrees for intake & exhaust. Except at idle. Have a look--I think this is going to allow you to fix your idle problem. RPM = 1200My slow gear I leave with 650 RPM, the IAC Position I leave between 5 and 6%, the Then your low idle problem will go away. But after sitting static idling for a little bit, the IAC goes to 100% & stays there. A few, however, get tangled up getting the idle control working just the way they want. Technically it is a warranty-voiding maneuver so proceed at your own risk. The Sniper EFI remote IAC (Idle Air Control) and plug is designed to gain installation clearance on some Sniper EFI 2x4 installations. 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. Cl. I am having an issue with the IAC on the Sniper. 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. Fortunately, these are much easier to solve. 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. Let's start by not assuming anything. Plus, you can email that file to me and I can be of more help. Yes, let me know how that setup process works. Going lower with the blanking might pay dividends, but there is so little room below 7/8 that you will quickly be in a range where every tiny variation in the TPS or MAP is throwing extra fuel into the engine. Sniper EFI offers superior throttle response and wide-open throttle power. Thanks for sharing that, Jason--great info! A common issue we see is a result of poor fuel pump grounding running a eyelet from the pump ground to a rusty or painted surface. If you haven't installed a = 2.34 It sounds a little different from mine, since it commands a 1300 or so increase intermittently. Your mechanical advance will naturally change the timing a bit but it should be fairly close. No air should be able to pass. Use the idle speed screw to set the idle at a comfortable warm-up speed. Holley have given a new unit. To do this, open up the Initial Startup gauge screen that was used in section 17.0. The manifold pressure increases with the throttle opening but the RPMs are still low. In most cases the IAC (Idle Air Control) circuit is the source of the whistle. I keep doing that with the same result. But after sitting static idling for a little bit, the IAC goes to 100% & stays there. If you have a bellcrank in your throttle linkage, ensure that the linkage is not engaging the bellcrank at an angle greater than 45 degrees at either end of the throw. Possibly cap, rotor, coil? If you find that adding 5-10 degrees of advance helps then it's time to do reconfirm TDC. 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. That is a good thing.I don't have a specific target RPM but always encourage automatic transmission users to bias the idle just a tiny bit higher than what you might otherwise. Fuel Flow lb / h = 12.1 Sometimes it sounds like it wants to crank at the start but runs out of gas. IAC looks good once it finally s fires. ps. If your TPS has snuck up to 2% then your IAC will be at the hold position, which by default is 30%. So try changing your IAC hold value slightly:Tuning : Advanced : Adv. EFI System Pro had everything I needed for my EFI upgrade. 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. They tell you to ask call Holley. Well, it sounds to me like your Sniper is doing its best to reduce your idle. 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. I figured out I was going the wrong direction when I was messing with the AFR programming. Wish I knew about it before I made my purchase. Note: The IAC breather hole is the roughly 1/4-inch triangular hole that sits above and between the secondaries. If you go the other way then you might find that the IAC zero's out when the fans are off. Though it started and ran good, it was dumping fuel and would not lean out to AFR set points. Holley EFI Electronic Fuel Pressure Gauge, article on choosing between Sniper and Terminator X throttle body solutions. 3 different fuel pumps. At some point you come upon problems that evade the easy answers and this is a good example. For someone in your position, it will become an indispensable tool in your tool box. After doing TPS reset it starts fine but when you give it some gas it hangs at 1500 and will not return to idle. 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. Maybe Holley will add Fuel Prime Multiplier to Terminator X later. If I read it correctly, the solution from the other thread seemed to fix a constant 300 or so RPM increase. I started with right after I first adjusted for 2% IAC and took pics about every 30 seconds over about 2 minutes. It is probably that your RPM above the maximum point at which ramp-down can occur. Contact whomever sold you your system or Holley directly. It then started working normally again. While it is not mandatory, I recommend the Sniper EFI CAN-to-USB Adapter to move the data between your Sniper EFI and your PC rather than trying to do this via the SD card. The AFR was pretty consistent around 13. When I removed the tape and started it again, it was idling at 1400-1500 RPM and sucking a bunch of air through the IAC, even though it showed 0% on the sensors screen (pic attached). Idle > IAC Kick. Your AFR is pegged lean. 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. Be sure to re-enable it once you get your idle tuned. But now that Terminator X is available, I highly recommend going that route. )If you rule out a fuel supply issue then we're going to have to gather a few more clues. This is extremely unreliable afrer warm. Then a little faster--until bogs at that level work themselves out. You will need to change the -40 degree idle speed setting again but I recommend not touching anything else. Both answers you've received greatly oversimplify the truth in favor of the answerer. And the rather cavalier "Absolutely!" When you open your IAC to 30% you are naturally going to have a high idle condition. However, whenever you start changing things, you can get into a chain reaction. 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%. The symptoms I had was a low cold start idle and going lean coming to a stop. Going back to what you said. idles good, runs amazing. The Sniper Quick-Start Manual provides the following instructions for setting the idle. Sniper EFI Idle Tuning. One additional wrap on the secondary coiled shaft spring is all that's necessary. 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.