To be honest, you sound like an ideal candidate for Sniper ECU ignition timing control. I am right back to where I started. I have adjusted many settings and eventually mess it up and go back to the original map. If you datalog the Sniper ECU and see multiple overlapping traces for the same signal, you likely have RF-induced problems. I, too, wish you'd bought your Sniper from us! I.e. The timing can drift 0-30 degrees just due to the width of the rotor tip. I' m going to put the 3 rd new pump this coming friday. When I drive with warm engine the IAC is at 30% when pushing gas, but shouldn't it be at 0%? Enjoy your Sniper! I have never seen issue when CTS is below 120 degrees. https://www.youtube.com/watch?v=2JpHlS1ymBc, If this is your first visit, be sure to I was shocked to see it at 95lbs!! Ultimately, it is about making the pedal softer, particularly at initial throttle opening. Good luck! Then it will ramp down to 1200 but will not return to idle. 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. At that point, with 90 PSI of fuel, the ECU can't turn the duty cycle down low enough to idle properly. My car will now start when its cold, but after about 30 seconds the idle drops down and begins to run like crap. I would suspect something is coming loose causing a stop to the EFI system/Fuel flow. The noise changes sound with the throttle position. So glad this was helpful. 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. This is very disappointing as people love to hear the motor while the hood is open.Thanks Jon. 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. I put it in neutral and the idle RPM had increased to 2100-2200. I installed the Holley Sniper in my Chevelle this winter with a brand new BluePrint 496. This value is itself enough to raise the idle a bit. My problem is low idle. Just thought I'd ask as there isn't a lot of info out there. 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%. Am I missing something. 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.) If I go any more it will ping. You're going to have to clean up the wiring in your engine compartment, In particular, look for spark plug wires that might be running near your throttle position sensor. I would gladly engage with you to solve this but ultimately you are going to need to go through whomever you purchased the system if a warranty return is in order. 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. Lubricate the linkage so there isn't as much native resistance. But after sitting static idling for a little bit, the IAC goes to 100% & stays there. It might be necessary to insulate or re-route your fuel lines if this can't be solved any other way. A good example of why it's so important to run a good pre filter in the fuel line. Supports up to 650hp with Four 100 Lb/Hr Injectors! It is a common one. Note: The IAC breather hole is the roughly 1/4-inch triangular hole that sits above and between the secondaries. Let's start by not assuming anything. Definitely would have went with you guys. It meets the target idle perfectly in either but if I lightly stab the throttle it tries to stall after slightly revving. I keep wondering how it was running so good with 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. Your second problem should be a bit more concerning. I have a Holley Sniper for almost 11 month now and it was running fine with no problems until now. In your case, however, I think you're close to getting it running. The first thing I'd do is check your fuel pressure with a gauge like this. Since a key cycle resets it to 0 and out to 30 or wherever The problem I experience is that after driving for about 10-15 minutes, the car starts idle to high. Always had to set idle above 950. 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. Sniper EFI Tuning & Tech. 30 minutes later CTS reads 161, start engine Idle is jumping from 450 (almost stall) to 1500, IAC is jumping all over 10 90. I had a customer recently with a high idle problem that he eventually traced to pad plug on one of the vacuum ports. Based on your situation above as well as some of other experiences, I recognized that I needed to improve my tuning procedures above to better explain what steps to take if that 10-step process doesn't completely solve the problem. The Sniper EFI system looks at the closed-loop fuel compensation required to reach your target AFR. That is the only way to fly. Do I need to try taping up the IAC port and setting the idle off the idle screw? Engine warms up to 195 degrees and stays. Free ground shipping regardless of order size! If I block off the iac with tape , I can get it to somewhat idle, but its not consistent. 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. First, I'm kind of insistent about not changing any of the default settings unless the vehicle absolutely will not cooperate enough to drive/learn, and only then if you have a specific understanding of the problem and a specific solution. About two minutes after I get it set at 850 & 5%, it has progressed to 100%. 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. 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. And your question is very perceptive: You must first know whether the bog is a lean or a rich condition before you can make the correct adjustments. Using the handheld, navigate to Tuning > Basic > Basic Idle and ensure your target idle speed is set to the RPM you desire. Installed sniper on 65 galaxie. 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. 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. By the way, this is a new installation on a 69 Camaro, stock 350, dual sync, etc. I looking for your expert opinion. You have to remove all hoses in order to debug the problem. However, I did have another fellow who contacted me that claims he went through three units before he could get one that would talk between the ECU and the Monitor. !I called Holley today, and before I could even described the symptoms the 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. This curve turns the idle speed down as the engine warms. Then it started behaving oddly. If you look down and your TPS is 2% then either your throttle is stuck slightly open (which itself will cause the idle-up) or RFI riding on the TPS signal has caused the ECU to see the throttle as open and, as a result, open the IAC to the hold position. If I read it correctly, the solution from the other thread seemed to fix a constant 300 or so RPM increase. 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!) I will confirm TDC with balancer but I have had balancer off and timed it before and after with same results. Thanks again Chris, your help has been invaluable.If anyone is considering going EFI, Chris is the man to chat with. Maybe Holley will add Fuel Prime Multiplier to Terminator X later. I think that a great number of the challenges that Sniper EFI System Owners face are brought on themselves by getting into the control settings before the system has really had a chance to learn. you have it set. When I first told him to check for leaks he looked back there and said "all good". Thanks. I'd suggest that you assume everything the previous owner did was wrong until you can prove that it was done correctly. Then you can take a close look at the IAC and see if it is opening. any ideas? When I put it in gear, it drops so low that it will stall if I don't add throttle. That way you can get into that part of the table that needs tuning, and you can watch your learn numbers grow. sniper Installation If you're installing a Sniper EFI system and almost ready to crank it over for the first time, this is the video for you! It shuts off when coming to a stop sign, at any cruising speed and romdomly at idle in park but never when excelerating. I will try the other stuff when I get off work. This is actually more troubling than the sound you originally described. A question I cannot get a 100% answer on is can you piggy back off the Sniper EFI TPS for an electronic transmission? Kind of cuts into forum time. If your mixture is too rich, it means there's too much fuel and not enough air. Thanks for your very detailed question! Usually it wont stay on 0% very long and soon changes to another number like 1 or 2%. I was 20 minutes into a drive yesterday when all of the sudden the RPM increased not commanded. 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. 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. Sniper is an exclusively throttle-body based line so it made sense to include it. And all too often we don't take that extra step of using a piston stop to ensure that the timing pointer is on zero when the engine is truly and exactly at top dead center. Hopefully replacing the pump again will resolve both issuesWhoa. Hello Chris. The fuel pressure regulator in the Sniper is fairly simple and not prone to failure, as far as I know. Also ensure the TPS Position returns to zero at idle, & the IAC Hold Position isn't setup too high. When I covered the IAC with my finger, the RPM dropped so low it stalled. And thanks again for taking your time to answer these questions. I would not expect that an electric fan would create a noticeable load on the engine but if it did then you'd want to set the idle screw when the fan was not running. My guess is a faulty IAC since it is intermittent and I have not done any setup changes. Nothing against Holley's method but I need to keep things simple and I do that by eliminating the effect of the IAC entirely while getting the idle speed adjusted. First--besides the fact that it's not represented on the display, it is not even a parameter that you can datalog. But he kept having problems so eventually he did a complete check and then he found the problem. Yes, it will talk to you--but not with words. 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%. started up the engine. When I finished the install on my C10, I set it as follows: 13.1 at idle, 14.2 at cruise, and 12.9 at WOT. Check fuel pressure too (. But if I take off from a stop and go to 1/4 or 1/2 throttle its fine and takes off like a banshee. carburetor setup, but it does blow when I can't jump on the highway like I use 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. i would have been happy to answer there. Laptop Access All in all, considering the system has been installed for less than 2 hours drive time we're BLOWN AWAY at how quickly it is "learning" this engine. Just getting it to act right at startup is a struggle. Featured Products Sniper EFI $7.07 - $2,457.95 470 Products View Parts author Staff Writer 1711 Posts An Article About Video tech Sniper EFI Videos Sniper EFI Tech Sniper EFI sniper Installation It has a lightweight centrifugal spring kit installed so I reach total timing around 2500 rpm. 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. Its just at low speeds, not sure if its loading up or leaning out. Holley Sniper IAC Surging???? Your mechanical advance will naturally change the timing a bit but it should be fairly close. With the engine still idling high park, set the brake, open the hood, and remove the air cleaner. Only show this user . I have it set at 650 and it idles anywhere from 590 to 700. I used the Casper's Electronics 108103 splitter and carefully soldered my connections. Intake has been on and off 3 times no change. Really appreciate the amount of learning im getting off here. knowledge with the sniper efi setup. I would suggest at that point you need to contact whoever is providing your tech support and find out why the default values are not working for you. Do you have a PCV on the engine? I installed the Sniper on my 1978 Ford F-100 with a small block Or ?I have put a fuel pressure gauge right at the inlet of the sniper and it is reading 60-64 psi. )If you rule out a fuel supply issue then we're going to have to gather a few more clues. Did you find this enlightening? 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. Hi I wish I had bought from you but I didn't find this site until now. I'm new to EFI and have no idea what to try next. I have driven it a few times maybe 100 miles or so. Often, folks will say, "I did everything you said. When you have the issue you should disconnect all hoses and plug the ports on the Sniper. Bolt on 4150 Flange Carburetor Replacement. How can I adjust the startup speed down to about 1400 RPM? (It should be at or near 60 PSI at idle. The progressive link can be a great solution on standard (non-Stealth) throttle bodies but I would install this LAST after everything else is working perfectly. It could be a problem with the power/ground for the Sniper but much more commonly this is a result of too much RFI. In the warm state IAC adjusted to a position of 2 to 10%. There's still a very small amount of airflow that squeezes past a closed IAC valve; it's that venturi like sound you're hearing. ps. Duration @.050 is 240 intake 246 exhaust with .574/.578 lift. If either of these is not the case it must be remedied.After you have done this then you might want to involve Holley Tech Support about the TPS, or it may be easier/faster just to visit the local auto parts store and pick up a new TPS and install it. It turns out that some of the Snipers are shipping with the minus 40-degree setting drastically lower, as shown in the following image. hard start about 1/2 throttle from stop it bogs down after 3 or 4 seconds.What I 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. I'm happy to walk you through what is required. It's pretty hard to get the header tubes glowing at idle with a lean AFR. That changes almost instantly as the engine revs.Since the learning algorithm requires some time exposure to a certain condition to make larger changes, that half-second makes only the smallest impact. After speaking with Holley Tech Support and Tech Support from where I purchased the systemthey decided to replace it. 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. The RPM would increase for no reason. https://www.gmperformancemotor.com/parts/19210007.html, http://forums.holley.com/showthread.3128#post83128, If this is your first visit, be sure to and go to restart warm, it catches starts for a flick of a second, drops to a stall, or sometimes will catch its self and start. Hello Chris. 400 engine, C6 3 speed automatic, with standard canister coil for ignition, and I have a 406SBC that does most everything right with this sniper setup. My Sniper is 99% great! My car will not idle right until it gets to around 130 -140 degrees. When I put it in gear, it drops so low that it will stall if I don't add throttle. Suddenly, the engine accelerates alone, hears a great deal of air being sucked in, I have tried your 10-step idle adjust and ive adjusted the idle curve. I am at the point where I almost insist that every Sniper EFI System owner purchase one of these. 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 followed the instructions and set the IAC to 2-9% when warm with idle at 850 RPM. Not to bandstand here but this is the point when where you bought your system is so important. The engine might run hot but if the timing is right it should keep that heat in the engine--which is where the damage turns up. 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. As you see above, the Sniper is going to dump in a maximum amount of fuel at zero TPS, begins to remove acceleration enrichment at 60 percent TPS, and then removes all acceleration enrichment correction at 100% TPS. It'll start & run till it's warm, then when I try setting the IAC every time, I try getting it between the 2 & 8% it quits. There are six different acceleration enrichment tables that you can tweak and that may be the way to go. :-). But before you adjust the ECU to lean the idle out, first confirm that your fuel pressure is right. All times are GMT-6. I also raised idle at Park a bit with the idle screw. Coming home from work today it was much warmer and took a little longer due to traffic. Edit I just ordered a Holley return / regulator and cap for the sniper ouletOh, this is not an OEM Master Kit, but the fuel pump should be the same EFI Pro shipped this kit. There is no real mystery here. Don't know if I should put this in a separate post. Hello, I am having a tps and idle issue. It starts cold fine, its just when its hot. My Sniper started having a ticking noise-- I have 90 miles on my Sniper, but this started the last 10 miles or so: it still drives fine, but it worries me so i've stopped driving it for now. The on board fuel pressure regulator in the Sniper throttle body has a small filter clipped over one end . have the system learn the higher speeds? But after sitting static idling for a little bit, the IAC goes to 100% & stays there. I do know that the reference angle is 57.5, the inductive delay says 100.0. The broad consensus has been that the Sniper is an amazingly straight-forward install and starts and tunes as expected. The Sniper even has a feature that allows it to use the idle timing to control the idle speed. There are a few tell-tale signs that can help you diagnose the problem. This is more of a bit of a reality check. Running the vacuum advance and of course I time it disconnected. 90% of problems, (INCLUDING MYSELF) could be answered/fixed by just reading the instructions. = 2.34 Bryan McTaggart 02/28/2023 news When I shut it off then start it Commanding the engine to automatically increase speed when switching into drive is a little scary to me though. When the lambda is 1.0, the displayed AFR is 14.7;1 REGARDLESS OF THE FUEL. EFI System Pro had everything I needed for my EFI upgrade. 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. 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. There is a chance that the IAC is open but displaying 0% so start by putting your finger over the IAC opening. Make sure that your blanking level is _below_ that (being careful not to find yourself in the situation I describe above.) I watched the butterflies start to open at about 35 on TPS. I was looking at a data log from my truck earlier this week and noted that at idle my IAC was zero. Confirm the placement of all wiring, ensure that the WBO2 sensor is positioned properly, etc. However, I can't think of a single one that was because of low vacuum. Ive also used another snap on light to confirm. 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. Reducing that a bit will help. In this short video you learn to replace the IAC. I started with right after I first adjusted for 2% IAC and took pics about every 30 seconds over about 2 minutes. A simple remove & clean will remedy this . Cheers Darren. mail today. I think I figured some of my problems outI'll try to explain. :-). School's out for spring break this week though so I'm covering for employees on vacation. I would only play with this if you are finding that the other adjustments I suggested aren't working. I'd say make sure you buy from someone who can give you good after-purchase help (hint!) Have you ever experienced a high idle once the engine reaches 200 degrees?Ive set my idle the way you said and it works great until the engine reaches 200 degrees. And so glad you guys are enjoying the Sniper EFI system. This page was generated at 12:25 AM. % = 49 That will happen occasionally, but less as time goes and on and the engine tune stabilizes. 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. When I covered the IAC with my finger, the RPM dropped so low it stalled. However, whenever you start changing things, you can get into a chain reaction. Holley Idle Air Control Motor Idle Air Control Motor Fits the Following Applications: Sniper EFI 90 mm, 92 mm, 102 mm Throttle Bodies Digital Pro-Jection Systems Avenger 4-bbl TBI Commander 950 Terminator TBI If you go the other way then you might find that the IAC zero's out when the fans are off. Hopefully replacing the pump again will resolve both issues. Hot start it most of the time wont start unless I give it a little throttle. If you go too high then the motor will not return to your target idle when you come off the throttle. I hold my foot steady in place it does this in 5 second cycles and if i let go of 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. You will have to do this until the TPS stays at 0% when the throttle is closed. I had this same exact issue. 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. 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. I guess we can't have everything. I figured out I was going the wrong direction when I was messing with the AFR programming. If you set the RPM above idle to start ramp too high, then it may not ever get down to the RPM above idle to re-enable. applies here because it is so important to realize that just because the IAC Also its extremely rich at idle. Capability Range: Advanced Well, it sounds to me like your Sniper is doing its best to reduce your idle. He said they have been having an issue with these lately. If not then you have some other issue that is behind this increased idle. I installed a sniper efi system on my 1969 Camaro. 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 Tech Tips and discussions are also great! to. 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 hard to know what the previous owner did right versus wrong. I followed the instructions and set the IAC to 2-9% when warm with idle at 850 RPM. If I were there in person I would test the function of the IAC (see this article.) If you did not rotate the distributor to set the actual timing to 15 that might be the only issue. 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. I have probably 200 - 300 miles on this engine and it has always done this. I straightened that out, got it running and that's where it goes downhill. Holly offers a very nice Analog-Style Fuel Pressure Gauge that is another option. This will let you know at a glance if something is going awry with the fuel pump. Hope this helps! Everything was working perfectly and I shut off the engine. And Earl's makes a fantastic little 100 PSI gauge. 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. I've not heard of any others with this exact issue so I don't think it is a common problem. The distributor was loose. You could go either way.. Several good bits here. Some advanced conceptsIf you have the Sniper Can-Bus to USB Adapter, you can connect your laptop, open the software to the learn table, and get a visual for where in the table you are experiencing the lean bog. That initial rev is going to be determined by your IAC Park Position. Ilike a few othersam having idle issues. Thanks for any help. If I cruise down the road at lets say 60 mph and lay into it, she will take off and go. It wont fire up. Turning it off and back on would reset it, and then it would work as advertised for a while. While this video is not meant for the Sniper EFI user it does provide a great overview of how your ethanol tuning adjustments must be made not only to the base fuel map but to the other configuration settings. The last pic is with the car in Drive. So you installed your Holley Sniper. The ticking is inline with the fuel pressure I feel squeezing both the fuel return & delivery lines (like a heartbeat). When stopping, the brakes are unable to overcome the engine so I go to neutral just to stop fighting the engine. The 10 step set up on your page set my idle perfect and iac perfect a very consitant 700. Earl's Mechanical Fuel Pressure GaugeI could use that for a quick troubleshooting for 1/3rd the cost of the Holley one. The solution is to either lower the IAC hold position or increase the RPM above idle to start ramp (default is 1000 RPM). To get it to idle the tps is at 2-3-4% even with linkage disconnected and a return spring installed. To keep it running in gear, I have to bump the neutral idle up just over 1000 RPM. 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. We are using Target AFR of 9.0: 1, Fuel Base approximately 40% higher. Keep in mind that at 60 miles the Sometimes an engine can produce enough vacuum to pull the secondaries open slightly. I'm also having a high idle problem but its different. *Possible delays due to Covid-19 click for more information. The Sniper resets the TPS to 0% each time that you key the system on. Thanks in advance for any advice. The IAC reads 36 when at idle fully warmed up.
— Actualités —