Tried that and it didn't work? I'd recommend you contact Holley Tech support to get their input (1-866-464-6553; call early for the shortest wait times.) :-). It is how the engineers allow you to clear a flood condition when you detect it. That way you can get into that part of the table that needs tuning, and you can watch your learn numbers grow. By the way, this is a new installation on a 69 Camaro, stock 350, dual sync, etc. Unfortunately I did not buy my sniper efi from you. It will drop down to 400 RPM then climb 500 and then shoot to 900 and then come back sometimes two or three times then catch it self an idle just fine again. Do please let us know what you find out! Capability Range: Advanced 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. I'm so glad you found this helpful--that makes my day!Don't get too concerned about the specific learn percentage. Resistance results in heat and heat results in more resistance. Seems to behave more better now. Get that thing installed and you're going to know a whole lot more about what's going on. This was an issue in the earliest version of the Sniper firmware. Once we recognize that, the next step is to narrow down all possible sources of additional air until we discover the cause.Start by keeping an eye on your IAC number. So you installed your Holley Sniper. Hello, I am having a tps and idle issue. One of the great features of Holley's Sniper is the ability to set your air/fuel ratio (AFR) where you want it.
Holley - 543-105 EFI Idle Air Control Motor , Black - amazon.com applies here because it is so important to realize that just because the IAC Simply use your handheld controller and go to the Tuning > Advanced > Advanced Idle > Idle Speed screen and click on the Idle Speed Curve function. They also recommended that their ground be spliced into the Sniper ground as close to the Sniper as possible. I pulled over and turned the car off and then back on. I will turn it up some more.Is this something that the ECU will learn? This will tell us if the ECU thinks that it is in control of setting the idle or if it thinks that you are driving the engine speed with the pedal. idle counts from 0. I would start by removing the progressive linkage. If the issue persists, you may need to replace the IAC. I did all of this before seeing the link you sent. I'm going to jump out on a limb here and say you either don't have adequate fuel flow or pressure. Do you have a PCV on the engine? Consider adding fuel in the AE vs TPS and/or AE vs MAP ROC tables in the area where the stumble is occuring.Since this is happening at such low TPS levels it is possible that your engine would prefer a lower (richer) target AFR number at idle. Inj. 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. Often, folks will say, "I did everything you said. Im thinking a faulty TPS. Without it you are working in the dark. If your fuel pressure regulator has failed (and they often fail by blocking return fuel and maxing your fuel pressure) then it could lead to rich idle, particularly until your engine gets up to temp. Enjoy! That is what I really respect about Holley. I installed the Holley Sniper in my Chevelle this winter with a brand new BluePrint 496. The learn percentage should gradually decrease to virtually nothing as the map plus learn table begin to get more and more accurate to your specific setup. This car has never idled under 900 without stalling with 3 carbs and does the same thing with sniper edit. Check fuel pressure too (. Shutoff engine wait 30 seconds, turn key wait for display to come up, start engine. At some point you come upon problems that evade the easy answers and this is a good example. And if you're going to go this route I'd recommend that you switch from "Simple" (3 A/F targets, one each for Idle, Cruise, and WOT) and go to the 2-D Table I've been trying to correct that 1% small issue/annoyance. If it does then you can put on a heavier spring so the advance doesn't come in as fast, or use a lighter weight. Super helpful and knowledgeable. Then you can take a close look at the IAC and see if it is opening. Do I have to hook up sniper ac wire to relay or should iac pick up idle? It started right up and we did your idle control fix and all is good at idle. Reply Quote. He is able to get it to start by quickly depressing the accelerator to at least 60% and releasing. I'll have to check again tomorrow. technical rep said "You ahve high fuel pressure". In fact, it is those users who seem to end up most impressed with the system. Could you provide me with some things to check or some things to adjust? It is always best to get the base map as close as possible before adding acceleration enrichment. Were the additional load a simple step function it would be challenge enough for the ECU to gracefully increase the engine speed without overshooting. Did your process to adjust idle to 860. Car has run perfect every time and has never hesitated or stalled since. Running the vacuum advance and of course I time it disconnected. The manifold pressure increases with the throttle opening but the RPMs are still low. the issue I had a customer recently with a high idle problem that he eventually traced to pad plug on one of the vacuum ports. Pricing was reasonable, shipping was prompt and Chris helped me with a wiring question during my install. The engine has 14: 1 compression ratio, we can not use gasoline. Really appreciate the amount of learning im getting off here. I also noted that after some time, I could change those values as I saw fit. 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. I have a set of 8.8 Accel Rfi suppression wires on it. At low levels RF interference will often reset the ECU so quickly that the engine will not stall. Capability Range: Professional 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. The Sniper EFI remote IAC (Idle Air Control) and plug is designed to gain installation clearance on some Sniper EFI 2x4 installations. Price Point: $$, Robust, feature-rich multi-port EFI systems offer easy plug-and-play late-model V8 engine swaps. first attempt but as it tries to idle down to the target RPMsit can never even All EFI systems need a large fuel filter to trap dirt and yet not reduce volume. If Don't be surprised if one or the other is slightly open. If not then you have some other issue that is behind this increased idle. Hi Chris thanks in advance for any tips. 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. Even then, recognize that over time the IAC will need to be readjusted to compensate for minor changes that will cause it to drift. And your understanding of how the throttle position affects idle is exactly correct. I've been messing around for a bit trying to eliminate any possible vacuum leaks. But nothing beats a good solid gut-check One thing you need to sync the timing and set the inductive delay. >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. Supports up to 650hp with Four 100 Lb/Hr Injectors! However, I have never found that to be the case. 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.
Sniper EFI Idle Tuning - Holley Motor Life Thanks so much for reading! At 0% it shouldn't be sucking any air through that port, correct? If you don't have a working coolant temperature sensor then it will never bring the idle speed down. This is very disappointing as people love to hear the motor while the hood is open.Thanks Jon. 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. The last pic is with the car in Drive. Purists will sniff that these are not accurate to the tenth of a PSI. To get it to idle the tps is at 2-3-4% even with linkage disconnected and a return spring installed. This is extremely unreliable afrer warm. Well, it turns out that with the current firmware this throws the IAC control into a bit of confusion. Target AFR at idle is 13.8%. If you have performed the adjustments above and still have RPM issues, it's time to look for clues. I'm new to EFI and have no idea what to try next. Okay, try my method. Advanced throttle body injection systems capable of transmission control and more. idles good, runs amazing. It's the same one that Holley puts in their Sniper Master Kits and I've never heard anyone with anything but good things to say about it. That could be a problem with the TPS or it could be some sort of throttle linkage issue. What would cause the idle to faulter like that? Comp. If you are idling at 2100 RPM (based on a default IAC Hold position of 30%) and your target idle speed is 900, then the ECU is not going to try to idle down. Next, clean the IAC and all related parts with brake cleaner. Learning to install these is great--you're about to embark on the next great adventure of advanced troubleshooting. When you experience this, before you touch anything or shut the engine down, first look at your TPS and your IAC. 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.) Cracked casing from a side cover screw being installed crossed threaded. On a cold start it will idle at 750 everytime, But if its hot start it will jump upto 1600rpm for 2 seconds then come back to 750. Your second problem should be a bit more concerning. If you complete the process and find that the IAC is less than 2% at idle, repeat the process and use the set screw to make the RPM about 60 RPM below the target. Remove the tape from the IAC breather hole and restart the engine. Though it started and ran good, it was dumping fuel and would not lean out to AFR set points. 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. Repeat until that stumble goes away, and then try a bit more throttle. )Then look a the datalog and find out what TPS ROC and MAP ROC is most likely to cause the problem. We'll also be contacting you for future purchases now that I've discovered you! I do know that the reference angle is 57.5, the inductive delay says 100.0. Well you were right air was entering from another source. I have it set at 650 and it idles anywhere from 590 to 700. Your comment doesn't imply any sort of problem that would make me give up on idle timing control. 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. Holly offers a very nice Analog-Style Fuel Pressure Gauge that is another option. About two minutes after I get it set at 850 & 5%, it has progressed to 100%. Commanding the engine to automatically increase speed when switching into drive is a little scary to me though. 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. 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. Does that make sense to you? 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. :-). 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. Does this seem reasonable and how hard will it be to get the idle and off-idle performance correct? Has a good size camshaft cant find any vacuum leaks. I think you will find that it will learn its way through this. We're having trouble with a Ford Maverick 302 V8, using ethanol. Thanks. That 60% (which is configurable) is known as the Clear Flood TPS. After speaking with Holley Tech Support and Tech Support from where I purchased the systemthey decided to replace it. This happens no matter how much I adjust the idle screw. If the screen shows iac at 0 and you block the hole to find it open what does that mean? I also raised idle at Park a bit with the idle screw. it will jerk and rpm will go up and down and AFR will be around 20 : 1 or more or less. The throttle plates are misaligned. 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%. If that happens then follow my 10-step process shown above. 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! The symptoms I had was a low cold start idle and going lean coming to a stop. check, I guess after reading everyone saying how great the system is after I would suggest you take a look at that if you haven't already.
IAC Testing Procedure for EFI Systems But, if the idle is so high that it is making you crazy then you might try dropping that number just a bit. Hot start it most of the time wont start unless I give it a little throttle. Holley have given a new unit. Incorrect connections will result in excessive resistance. If I read it correctly, the solution from the other thread seemed to fix a constant 300 or so RPM increase. After 50 on the throttle position I'm not sure if the whistle goes away or you just can't here it anymore. Copyright 2022 Holley Performance Products, Inc. All right reserved. 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. 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. 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. )Since this isn't a consistent issue with all Snipers that tells me that different IAC settings tend to make the whistle. The fuel pressure regulator in the Sniper is fairly simple and not prone to failure, as far as I know. 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. Simply go to those cells, tweak them up or down as required, and the ECU should now be able to learn its way around the bog. If you go the other way then you might find that the IAC zero's out when the fans are off. Once it decides to come back down, it does so with no issue. Setup: 1965 Impala SS; ZZ6 Crate Engine, EFI Distributor. I am Japanese who attached Sniper EFI. Either the Walbro pumps you are getting are not genuine (lots of forgeries being sold) or else you have something that is killing them. This increased idle speed is triggered by grounding the orange wire in the 10-pin I/O harness. Your suggestion to remove the PCV valve is just for diagnosis purposes, right? Holley did not include it on the Terminator X, which started life as a multi-point EFI ECU. hard start about 1/2 throttle from stop it bogs down after 3 or 4 seconds.What I Hello Chris. One of them might be faulty. OK, I did the baseline idle speed screw setting.
Idle IAC problems? - Holley Performance Products Forums My car will now start when its cold, but after about 30 seconds the idle drops down and begins to run like crap. :-) Just don't let the parts go flying. Physially manipulating the linkage by hand will generally reveal if you have a sticking linkage that is preventing the TPS from returning from zero. Your closed loop compensation is adding a full 50% fuel. Yes its at 95lbs, needless to say he promised a new regulator would be in the Try it! It then idles up from 750 to 1100. 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. And so glad you guys are enjoying the Sniper EFI system. Some suggestions: i did have the same problem.try lengthening the lever of the throttle.meaning the length from the center of the throttle to the point where you attach your cable or your rod from the peddle. If your RPM is 2000, your TPS is 0, and your IAC is not closing, then there is some problem. When I am coming to a stop, the rpms will hang at 1200-1500 rpms. I straightened that out, got it running and that's where it goes downhill. I recommend you have a look:https://www.efisystempro.com/efi-pro-hangout/holley-sniper-efi-instruction/solving-sniper-rfi-problems, I recently purchased your fixed linkage to open primaries first and the throttle linkage extender to also get a smoother pedal. I have driven car about 200 miles. I keep wondering how it was running so good with I went on the good ole interweb and found your website which was VERY helpful!
Holley EFI 543-105 Idle Air Control Motor Let me start with the engine not starting until you press the throttle. This software is going to allow you to open both the configuration file and the datalogs that you create, overlay them and you can get a much better idea of what is happening. The problem I experience is that after driving for about 10-15 minutes, the car starts idle to high. In that case, and if you have an EGR valve, I might be suspicious of something going on there. This may require shortening or lengthening a rod. I recommend confirming there is no throttle linkage issue first.
Holley Sniper IAC Surging???? A problem since day 1 - YouTube :-). I figured out I was going the wrong direction when I was messing with the AFR programming. I was looking at a data log from my truck earlier this week and noted that at idle my IAC was zero. 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. Please advise. Common killers: No filter in front of the pump, reverse wiring, driving with PWM voltage, running at dead-head pressure.Since it sounds like your pressure is right, and since the Holley system doesn't provide a PWM voltage, that pretty much rules out everything but the lack of a filter. Contact whomever sold you your system or Holley directly. Stupid question, but where do I see if it's entering Learn mode? The biggest issue is these problems are intermittent meaning they do not occur all the time. Do you have any clue? It might be necessary to insulate or re-route your fuel lines if this can't be solved any other way. Ensure that the secondary linkage is completely closed (both visually and manually.). Thank you for this guide on setting IAC. The engine ran so good, I would have never suspected the Fuel Pressure to be an When you first posted this I had no idea how to respond. Take it a step at a time. Price Point: $, Advanced throttle body injection systems capable of transmission control and more. Using the handheld, navigate to Tuning > Basic > Basic Idle and ensure your target idle speed is set to the RPM you desire. But I am having troubles.When stepping on the accelerator slightly with idling, it will be 2000 RPM all the time. I would start by datalogging the situation and seeing exactly what your learn table looks like in the area immediately around the tip-in. i'm having is I can't seem to get the truck to run faster than 45 mph at speeds My issue is that when Im in stop and go traffic, I can let off the clutch and the engine revs and doesnt quite want to come back to idle. My IAC and TPS show zero when it does this. 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. I have driven it a few times maybe 100 miles or so. !I called Holley today, and before I could even described the symptoms the The jack-rabbit start can usually be minimized by adjusting the throttle linkage. This will go a long way to improving your fuel map without manually adjusting the acceleration enrichment. Note: The IAC breather hole is the roughly 1/4-inch triangular hole that sits above and between the secondaries. I can get it to fire up on the It shuts off when coming to a stop sign, at any cruising speed and romdomly at idle in park but never when excelerating. Fortunately, Holley has another product that can solve that: Hydramat.. Hydramat is not inexpensive but you won't believe what it can do.