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. Hot start it most of the time wont start unless I give it a little throttle. Your issues are likely related to one of these two things. Relatively new Sniper EFI install on a '69 Mustang 302.
Holley - 543-105 EFI Idle Air Control Motor , Black - amazon.com I certainly appreciate your frustration (as well as your wife's!) Well, it sounds to me like your Sniper is doing its best to reduce your idle.
IAC Calibration / Hanging rpms | Team Chevelle Reducing that a bit will help. 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. 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. To get it to idle the tps is at 2-3-4% even with linkage disconnected and a return spring installed. But they are 100% committed to your satisfaction. Great work, expert! The engine makes very low vacuum at idle. 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%. That is not something I'd ignore. The problem I'm having is I cant get the IAC to drop down off 100%. Price Point: $, Advanced throttle body injection systems capable of transmission control and more. I installed a sniper efi system on my 1969 Camaro. In this short video you learn to replace the IAC. I hope everyone enjoys this v. And Earl's makes a fantastic little 100 PSI gauge. We have shipped quite a few of these to customers in Australia and New Zealand so I know that there is becoming a good following there!We recommend this Inline 10-micron fuel filter to prevent problems like that. :-). I did check for the lightning under the hood but all was well.
Holley Sniper EFI 550-552 Holley Sniper EFI Autolite 1100 - Gold It didnt do this with the carb on it. Doesn't want to start, runs like crap. Also its extremely rich at idle. A couple of possibilities that come to mind in order of likelihood: Im having an issue with what I think is the Iac. If I put the truck in neutral the TPMS will raise all the way up over 2000. When you first posted this I had no idea how to respond. Really appreciate the amount of learning im getting off here. Don't be surprised if one or the other is slightly open. With select intake manifolds, the distributor housing and IAC valve on the back of the Sniper EFI throttle body are fighting for the same . Chris---I am contemplating replacing my Holley 750 on my new low vacuum 600 HP 496 with the Holley Sniper FI system. Add To Cart. When the lambda is 1.0, the displayed AFR is 14.7;1 REGARDLESS OF THE FUEL. After this whole process, the car normally rotates without a very abrupt pedal. When I drive with warm engine the IAC is at 30% when pushing gas, but shouldn't it be at 0%? The small rubber plug had a leak. So the issue Im having is low idle. Across the board, all of our customers say how impressed they were that it started and ran right out of the box just by following the simple installation instructions. 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%. You just need to go back through the IAC adjustment procedure now that idle timing control is enabled. What you are experiencing is rather common. Holley will take a look and tell you you have RFI and wish you good luck in finding it. Your mechanical advance will naturally change the timing a bit but it should be fairly close. Can the return line be an issue?I have had 2 faulty gpa-4 255 walbro pumps go bad. Hello, Chris, thanks for the help.I have not installed the software yet, and I'm having trouble with two cars. 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. By going into the IAC settings and turning off the Idle Spark control and setting Target Idle to 750 RPM my idle issues are gone, and it now returns to desired idle after cruise. If the minus 40 degree setting is lower than the setting to the right, simply move it up so that it looks something like this: The folks who have tried this have found that their idle speed control behaves much more as they expect. What an amazing site you have here. How can I adjust the startup speed down to about 1400 RPM? It sounds like you need a bit more of a fuel squirt on acceleration, Brett. I took some pics of the sensors page this morning after the car warmed up. 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. Any suggestions would be appreciated. Should I just disable idle timing control? A few, however, get tangled up getting the idle control working just the way they want. Setup: 1965 Impala SS; ZZ6 Crate Engine, EFI Distributor. No problems with either cold or hot starts. 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. The IAC is hanging open and not really at 0. 680-700.I can't find any reason other than it looses where it is in the firmware with Throttle Tip-In puts you in a part of the fuel map where you stay for only milliseconds at a time. For the first couple of drives it was running well, Sniper EFI was working exactly as advertised. Ok, so there are a couple peculiar things going on here. I installed my Sniper and the engine fired up great. Incorrect connections will result in excessive resistance. Does this seem reasonable and how hard will it be to get the idle and off-idle performance correct? Always had to set idle above 950. idle at 1100 on the "stock" file it's better with street strip.The IAC counts will be at zero. Cheers Darren. I keep wondering how it was running so good with Of the two options, I generally recommend the self-learn. Then, when you experience the high idle, note if the IAC number has increased. I recently bought the car with the EFI system on it. Definitely not 90. I set the AFR at 13.5 and all is good now. To be honest, you sound like an ideal candidate for Sniper ECU ignition timing control. Give us a hand! Im not sure what its doing, have messed with after start fuel, fuel at cranking. Please check your process again and see if you can see very specifically what is not working correctly. (Grease can sometimes do the same thing as a more permanent gasket sealer without making the removal of the air cleaner such a pain.). Copyright 2022 Holley Performance Products, Inc. All right reserved. If you don't have a working coolant temperature sensor then it will never bring the idle speed down. That 60% (which is configurable) is known as the Clear Flood TPS. is jumping all over the place when you experience this condition, it does not have the system learn the higher speeds? 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. It's pretty hard to get the header tubes glowing at idle with a lean AFR. So as much as I can I have been taking off real slow and let it fall on itself to try to learn and its not learning its way out of it. If I put the truck in park it comes down to idle. 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 didn't find your site until I was having trouble. The biggest issue is these problems are intermittent meaning they do not occur all the time. Ensure there isn't a vacuum leak causing the IAC Position to drop to 0%. I appreciate everything you are saying. The Super Sniper will allow you to monifor fuel pressure if you add an electronic sender but this is not an option with the standard Sniper. The AFR was pretty consistent around 13. Thank you. Second--even in the HP and Dominator systems where a fuel pressure sensor can be dalogged and displayed, the fuel pressure is not fed back into the algorithm. 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. After it starts it idles around my 960rpm setting + or - 100rpm. Note: The IAC breather hole is the roughly 1/4-inch triangular hole that sits above and between the secondaries. shut truck off. Idle was around 1000 mark and iac 0. I go into much more detail about that in this article on startup tuning. Don't try to correct for the fuel. 3 different fuel pumps. Could you provide me with some things to check or some things to adjust? Was perfect idle iac reading 3. The car cruises fine, and if I was to keep idle at 2000rpm the issue wont happen, its only when the car tries to ramp down to idle position.Thank you for your help, any advice would be appreciated.Thank you,Eric, Whenever we see the AFR go to "Heating" that is an indication that the ECU has been reset. I have now determined with the TPS the noise correlates with the opening of the secondary butterflies. Hopefully replacing the pump again will resolve both issuesWhoa. But if you can datalog the bog you can know much more precisely what is happening. Ensure that the secondary linkage is completely closed (both visually and manually.). In the setup, I set the hot idle for 850. Others might require 60 RPM. Take a drive and stop somewhere for 30 minutes, CTS is 170 when engine was shutoff. If the IAC is zero, and if putting your finger over the IAC port doesn't lower it, then it's not the IAC circuit. You want to ensure that nothing is hung up in there.The only thing that I can think of that would cause the fuel pressure to spike when the motor starts is the increased fuel flow at the higher alternator voltage (jumping from 12.0 to 13.5 volts or so.) There is a chance that the IAC is open but displaying 0% so start by putting your finger over the IAC opening. I figured out I was going the wrong direction when I was messing with the AFR programming. That is certainly not normal! I think in some of the Wizards with the handheld it doesn't use 57.5 as the default. The fuel pressure regulator in the Sniper is fairly simple and not prone to failure, as far as I know. carburetor setup, but it does blow when I can't jump on the highway like I use 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. After manually making the sensor go through the full range a few times, I reinstalled it and now my TP will read anywhere from 0% to 4% when I key on. Several good bits here. All times are GMT-6. Hi Chris. Holley Sniper Iac Delete 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.
Sniper EFI Problems - Holley Performance Products Forums I am having an issue with the IAC on the Sniper. 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. If your TPS is at zero and your IAC is at some random number above 8% (but not exactly 30%) then for some reason your engine has not met the conditions to ramp down to target idle. Going back to what you said. I also tried changing roc/map to 8 from 15 again no change at all.My ve table is smooth and tuned I even changed my AFR to 13.5 from 14.2 and no change at all. holley efi. Start engine let it warm up to 160, learn mode is learning. Glad to hear that you have timing control enabled, Gary. Sniper EFI offers superior throttle response and wide-open throttle power. He is able to get it to start by quickly depressing the accelerator to at least 60% and releasing. Thanks for the great question! Capability Range: Professional Supports up to 650hp with Four 100 Lb/Hr Injectors! Now that you've installed at least four Snipers it is going to be imperative that you learn to create and read datalogs. May God's grace bless you in the Lord Jesus Christ. 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. The problem I believe this is creating is after I start vehicle (and its still in park), the IAC drops down to my hold percentage of 10% (since throttle % is not 0) before engine is warm and therefore causing the engine to stall out. Engine has never stalled with Sniper system, once placed in Drive it just goes!!! Is this an issue to worry about? Second, Holley just released over the weekend a video on how to implement a flex fuel sensor on their HP and Dominator ECU's. It's going to be really difficult to nail down the problem with the several simultaneous changes that you've made. Should it not do the opposite and do this on a cold start not warm. 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. back upthe RPMs shoot up to anywhere between 1500 and 2000 and they will not get If it creates an issue (not normally the case) then you'll know. You should get a light spray evenly distributed in all four barrels. Hello Chris. !I called Holley today, and before I could even described the symptoms the I have an entirely separate article on Solving RF Intereference Issues. check out the. The broad consensus has been that the Sniper is an amazingly straight-forward install and starts and tunes as expected. Let Idle Tuning is a very important part of tuning any EFI system, especially our self-learning units like Sniper or Terminator X EFI. You might have a bad O2 sensor, really bad exhaust leak or a problem with the ECU. Super helpful and knowledgeable. Lubricate the linkage so there isn't as much native resistance. I have a set of 8.8 Accel Rfi suppression wires on it. )If you rule out a fuel supply issue then we're going to have to gather a few more clues. Holley Sniper EFI Troubleshooting Mudford Garage 8.6K subscribers 38K views 3 years ago My Bronco with Holley Sniper EFI was running poorly. The tps has slotted holes, can you adjust it to get to zero? It shuts off when coming to a stop sign, at any cruising speed and romdomly at idle in park but never when excelerating. It will still change a bit with weather changes and when you get into infrequently-used sections of the map, but it's nothing to worry about.Regarding your idle speed immediately after start-up, that is determined by your Idle Parked Position. They are prone to be inaccurate. By the way, this is a new installation on a 69 Camaro, stock 350, dual sync, etc. When stopping, the brakes are unable to overcome the engine so I go to neutral just to stop fighting the engine. Took it for a lap around the block and came back. If you haven't confirmed that they it is worth checking. But I am having troubles.When stepping on the accelerator slightly with idling, it will be 2000 RPM all the time. Both answers you've received greatly oversimplify the truth in favor of the answerer. This will go a long way to improving your fuel map without manually adjusting the acceleration enrichment. 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. After talking to Holley tech, I replaced the factory regulator and problem solved.The regulator had what appeared to be a film or something almost clear embedded in some of the screen, maybe from factory or from install, but that was my issue.PS : this page and other forums have helped me a lot. The first 250-300 miles were amazing as the Sniper EFI worked flawlessly. If the TPS reading on your Sniper EFI System does not reset to zero that is a problem that needs to be addressed. The warmer the motor, the higher the idle will be at this point. Ive tried setting the prime setting above 150 but it wont take, it always goes back to 150. It could be, but that seems unlikely.Instead, you need to look at the basics. OK, I did the baseline idle speed screw setting. When I turn the key on I can hear it prime, but I don't think im getting enough fuel. This value is itself enough to raise the idle a bit. Please advise. The latest was changing the power brake booster.Today I drove it to work and no issues at all. That initial rev is going to be determined by your IAC Park Position. I looking for your expert opinion. :-)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. 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. Cycle the ignition as instructed by the handheld and then navigate to the distributor setup screen. If I try and get the 2-10% i get all the way up to 1200 rpm. Try it! 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. My issue is that the TP% will not reset with key cycle and its idleing at 9% TP. At 0% it shouldn't be sucking any air through that port, correct? I think that your Sniper system is working fine but would definitely check ouf the fuel pump. If you remove the air cleaner entirely and the whistle continues then you can rule that out. check out the. is the fuel pressure. But get that fuel system fixed before going any further. Is that normal? NOTE: Do not attempt to set the target idle speed and IAC position until the engine is above 160F! First thing I would check If idle drops below 800 it wont come back itll chug around 300 rpm for a few seconds then die.
Sniper EFI Problems - Holley Performance Products Forums 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. If this is the case then some adjustment of the linkage or the butterfly plates themselves is necessary. The next time it happens is the perfect opportunity to find the problem. Its timed to 36 degrees. I was 20 minutes into a drive yesterday when all of the sudden the RPM increased not commanded. Data logs show no EMI/RFI. There is no sense proceeding until your TPS is at zero at key-on. The very first thing I would do is get ground truth on your timing. 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. It sounds to me like it is way retarded.In the event that the timing is right then take a look at your AFR--the actual AFR, not the target. Thanks. It's not necessary to drive it that way. You're going to have to get this fixed or it's going to cause even more problems than the high idle. 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. I installed the Holley Sniper in my Chevelle this winter with a brand new BluePrint 496. I'd suggest that you assume everything the previous owner did was wrong until you can prove that it was done correctly. Running a bbc with coil - my timing is perfect. Thank you. Does anyone have photos of this additional return spring they installed? If I read it correctly, the solution from the other thread seemed to fix a constant 300 or so RPM increase. Your closed loop compensation is adding a full 50% fuel. All of the wiring exits below the rear fuel injector cover, for a completely stealth installation. I have not heard of this. Interesting question. 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. We'll also be contacting you for future purchases now that I've discovered you! TP range is normal goes up to about 90% with throttle pedal to the floor. I have driven car about 200 miles. If the ECU has not spent some significant time learning yet, I'd recommend going back through the setup wizard and getting everything back to default. When I see that your TPS is 1%, that tells me that you may have an RFI problem. This item: Holley - 543-105 EFI Idle Air Control Motor , Black $71.72 Holley Sniper EFI 870001 Throttle Position Sensor $34.60 Holley 860004-1 92MM Sniper Throttle BDY $223.93 Customers who viewed this item also viewed Page 1 of 1 Start over Holley EFI Idle Air Control (Iac) Valve Motor 30 13 offers from $79.56 when things aren't working and this provides just that. I know this is old, but I bought and installed a Sniper kit in 9/18. Price Point: $$$. 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. The Street/Strip and race cam setups tend to be too rich initially. Good luck! Hello Chris. School's out for spring break this week though so I'm covering for employees on vacation. Do I need to try taping up the IAC port and setting the idle off the idle screw? Since it is unlikely that anything else changed it is most likely the IAC is problematic or the butterflies are not shut all the way.
Holley sniper, bogging/ losing power "NOW FIXED" You advise would be greatly appreciated. Target AFR, A / F = 13.5
Holley Sniper EFI Problems: Best Fixes According to Manufacturer If the screen shows iac at 0 and you block the hole to find it open what does that mean? The "Gauge Text" is what would be shown on a 2-1/16 gauge or the Avenger handheld display. We are using Target AFR of 9.0: 1, Fuel Base approximately 40% higher. Both Sniper and trans controller grounds were direct to the battery ground, as they should be. 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. I'm new to the efi thing and any help would be seriously appreciated. I think you will find that it will learn its way through this. Holley EFI Electronic Fuel Pressure GaugeI think its a little ridiculous that I cant see fuel pressure on the display even though its measuring it but whatever. That's a nice change of pace--a low idle issue! I guess we can't have everything. 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. Thanks in advance for any advice. In addition to avoiding this particular problem, the total solution is much better. Ok, we have enough Sniper systems out there that I thought it would be a good idea to create a posting on challenges that might arise during installation. What I would recommend is getting somewhere that you can spend a significant amount of time doing starts. Chris, I recently installed my Sniper and have an intermittent idle problem. Idle : IAC Rampdown : IAC hold positionChange this by maybe 2% in either direction. One of them might be faulty. Has a good size camshaft cant find any vacuum leaks. I would continue checking the electrical connections along the fuel supply. (Don't drive and watch--get a helper!) I watched the butterflies start to open at about 35 on TPS. I put it in neutral and the idle RPM had increased to 2100-2200. But I wanted to go ahead and answer this so that it would make sense to someone who might not go that route.I think the first thing I'd do is try another pressure gauge. The solution is to either lower the IAC hold position or increase the RPM above idle to start ramp (default is 1000 RPM). Yes, it will talk to you--but not with words. You've got it running and warmed up but now you need to set. Hey Chris If not then I think you are going to find that this will solve much of your problem. This is a mighty big subject for a blog post reply, I should probably start doing some videos on this. Hang in there--you can do it. If you do find you have RFI issues then I've written an
article on solving RFI problems. You may have to register before you can post: click the register link above to proceed. You are looking in the right area but I would probably not change the ROC blanking. Hope this helps! Since the load is more of a wave that increases the most initially and then decreases again, the ECU is doing really well to get the idle under control in only two or three over/under shots as you describe.You don't mention if you have your Sniper ECU controlling timing. When the secondary throttle blades are centered in their bores and pivot freely, an additional return spring is not necessary. Bolt-on carburetor style EFI for your classic car or truck. But, whether your vendor provides you with tech support or sends you to Holley, I'd start by getting them a data log and asking for some insight. If your mixture is too rich, it means there's too much fuel and not enough air. Intermittent stalling usually points to radio frequency or electro-magnetic intereference (RFI/EMI). Thank you very much. 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. Take it a step at a time. 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. If you use your handheld to go here: I've been trying to correct that 1% small issue/annoyance. Strangely, what I've seen is that it idles too lean as the injectors are effectively shut off.Thanks again for the follow-up and glad to hear that everything is working well now. Follow this link to download it for free if you have not already done so. Suddenly, the engine accelerates alone, hears a great deal of air being sucked in, And, hopefully, within those degrees you will find a place where you don't get the whistle. I have a feeling it's something simple but I thought I'd ask you first before I inadvertently change something that affects other areas. Physially manipulating the linkage by hand will generally reveal if you have a sticking linkage that is preventing the TPS from returning from zero. I have adjusted many settings and eventually mess it up and go back to the original map. The second thing to realize is that even after you get it just right, you need to keep an eye on the IAC number and reset the idle if it gets outside the 2-8% range when idling when warm. The Sniper EFI remote IAC (Idle Air Control) and plug is designed to gain installation clearance on some Sniper EFI 2x4 installations. All times are GMT-6. This page was generated at 12:25 AM. Wish I knew about it before I made my purchase. Turning it off and back on would reset it, and then it would work as advertised for a while. There are a few tell-tale signs that can help you diagnose the problem. TPS 0. And since they really had an insanely-tight monetary and real estate budget in the Sniper EFI System, it is unlikely that the added something that wasn't absolutely necessary--and then forgot to use it..And you are spot on about the little Earl's gauge with optional -6 AN port. When I cover it with my hands, it gets quieter. 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. These problems will go away when you do that. 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. Last night I tried setting the IAC and had the same problems after it's warmed up. After speaking with Holley Tech Support and Tech Support from where I purchased the systemthey decided to replace it. 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.