It is working fine when you restart the car, controlling idle perfectly at 8 steps open so it is unlikely to fail when the car warms up--or correct itself instantly when you restart it..So, if you don't have any vacuum leak, and the throttle plates are fully closed, the only thing I can guess is something is causing your ignition timing to change. Hello Reducing that a bit will help. I will a, Scott has been very helpful and informative on guiding me through the purchasing and installation of my terminator X max system. Technically it is a warranty-voiding maneuver so proceed at your own risk. But there are several degrees of play there in which it should still work fine. Hi Chris I didn't get any traction on Holley.com I chased that gremlin for about three weeks and was convinced I had a bad throttle cable. If that tested out okay then I can really guess that there might be some sort of intermittent, temporary RFI. That is the default "Clear Flood" TPS setting and turns all fuel off until the engine cranks. If you use your handheld to go here: Or alternator? Note that sometimes you can get into a back-and-forth situation. When you set the Static Timing to 15, what did you read with the timing light? Hey Chris If I read it correctly, the solution from the other thread seemed to fix a constant 300 or so RPM increase. Hi I wish I had bought from you but I didn't find this site until now. Maybe here will work better ?Sniper High Fuel PSIMy fuel psi is over 90 according to a brand new Auto Meter pro mechanical gauge tied in at the inlet to the Sniper using an AN adapter.I did the search function on here and found a similar high PSI issue that was fixed by clearing the return line.I have checked the return line hose for kinks and have removed it and blew thru it without any back pressure. Definitely not 90. I have a 406SBC that does most everything right with this sniper setup. About two minutes after I get it set at 850 & 5%, it has progressed to 100%. Without it you are working in the dark. The weather in Ct has finally improved and I have put about 60 miles on the car with the Sniper system. You can re-enable this after you have completed this idle speed adjustment process. 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 Only in the unlikely event that your engine simply won't run well enough to drive and self-learn should you consider tweaking anything inside of the first several hundred miles. When I put it in park the idle RPM was 2100-2200 each time. It could be a couple of things. But after sitting static idling for a little bit, the IAC goes to 100% & stays there. The engine has 14: 1 compression ratio, we can not use gasoline. Holley EFI Electronic Fuel Pressure Gauge, article on choosing between Sniper and Terminator X throttle body solutions. Possibly cap, rotor, coil? 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. With an assistant pressing the accelerator, you need to make sure that when the accelerator is pressed to WOT that the throttle blades are fully opened, and when accelerator is lifted the linkage is fully at rest against the idle speed screw. Yes, having an accurate TPS is very important at idle. It reads 0 at idle and when I accelerate it goes up to 30 and makes a loud sucking sound that seems to be holding the car back. Of the two options, I generally recommend the self-learn. Is there away to program the ecu to compensate for this at start up. That, I am afraid, is going to involve a little bit of luck if you don't want to create a 250 MB data log. (If you do this you will need to reset the -40 degree setting mentioned at the top of this article. 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. We have never had that problem with any of the units that we have shipped. 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. But, if the idle is so high that it is making you crazy then you might try dropping that number just a bit. So I have been doing the slow take offs and thinking that it would learn its way out. Hi Chris thanks in advance for any tips. I have it set at 650 and it idles anywhere from 590 to 700. It shuts off when coming to a stop sign, at any cruising speed and romdomly at idle in park but never when excelerating. Now that you've installed at least four Snipers it is going to be imperative that you learn to create and read datalogs. OK, I did the baseline idle speed screw setting. Drop the IAC parked position a bit at each temperature point and sort of back into the solution. Tried that and it didn't work? Turned it off and on again. When I first told him to check for leaks he looked back there and said "all good". And the only way to be positive about that is with a gauge.Unfortunately, the Sniper does not provide an input for an electronic sender so the next best thing is an analog gauge. Even at 0% it's sucking a bunch of air through the IAC port. https://www.gmperformancemotor.com/parts/19210007.html, http://forums.holley.com/showthread.3128#post83128, If this is your first visit, be sure to If you did not rotate the distributor to set the actual timing to 15 that might be the only issue. Take it a step at a time. 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. Shut off the engine, ensure power to the Sniper is switched off. Sometimes an engine can produce enough vacuum to pull the secondaries open slightly. I have driven car about 200 miles. These problems will go away when you do that. Okay, try my method. When you have the issue you should disconnect all hoses and plug the ports on the Sniper. Give us a hand! It felt like it was flooding out at low speed, low. Yes its at 95lbs, needless to say he promised a new regulator would be in the He has walked me through every question Iv. Will restart but only for a minute or so a couple of times then shuts down fuel delivery and will not restart. Somehow air is entering the engine that was not entering the engine when you originally set the idle speed screw. hard start about 1/2 throttle from stop it bogs down after 3 or 4 seconds.What I Did you find this enlightening? If you go too high then the motor will not return to your target idle when you come off the throttle. Idle IAC problems? - Holley Performance Products Forums have noticed on the hand held is that Air/fuel Ratio rises to 20 +/- A/F and the My car will now start when its cold, but after about 30 seconds the idle drops down and begins to run like crap. I have never seen issue when CTS is below 120 degrees. He thought that something was wrong because when he set the idle 50 RPM below his target the resulting IAC postion was far too big. Hope this helps! 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. 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. It sounds a little different from mine, since it commands a 1300 or so increase intermittently. It's not that they (or any other manufacturer) is 100% perfect. The engine makes very low vacuum at idle. Holley Sniper IAC Surging???? A problem since day 1 - YouTube What might cause the TPS to go to 2%? Resistance results in heat and heat results in more resistance. My dad wanted to recheck the timing so I set the Static Timing at 15 and it runs perfect. Properly configured, the Sniper does a fantastic job of responding to the transition from Park to Drive. Price Point: $, Advanced throttle body injection systems capable of transmission control and more. First, let me congratulate you on your patience in letting the system learn. Don't know if I should put this in a separate post. About two minutes after I get it set at 850 & 5%, it has progressed to 100%. I figured out I was going the wrong direction when I was messing with the AFR programming. That 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. Do I have to hook up sniper ac wire to relay or should iac pick up idle? New install, when in setup wizard TPS says 90 percent and I checked the linkage and butterflies. 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. The solution is to either lower the IAC hold position or increase the RPM above idle to start ramp (default is 1000 RPM). Sniper EFI - Holley carburetor setup, but it does blow when I can't jump on the highway like I use 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. Does that make sense to you? Good luck! Should it not do the opposite and do this on a cold start not warm. 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. Top 10 Sniper EFI Installation Tips from Holley's Tom Kise Try it! Save Share. If I put the truck in park it comes down to idle. I think that your Sniper system is working fine but would definitely check ouf the fuel pump. This was an issue in the earliest version of the Sniper firmware. When you key on, you will hear three distinct sounds: The ECU initializing the IAC, the fuel pump priming, and the injectors firing their prime shot. EFI Troubleshooting EFIand and EFI Tuning Tips - In The Garage Media The following are status commands and diagnostics for sensor and various parameters in the Holley software. Ive also used another snap on light to confirm. I tried adjusting my IAC up to 10deg in both directions with no change. Running the vacuum advance and of course I time it disconnected. Fortunately, these are much easier to solve. Duration @.050 is 240 intake 246 exhaust with .574/.578 lift. Chris thank you for the info. When I cover it with my hands, it gets quieter. Holley sniper, bogging/ losing power "NOW FIXED" It is reliant on the data acquired by the included wideband oxygen sensor. )Then look a the datalog and find out what TPS ROC and MAP ROC is most likely to cause the problem. However, I always preach to never touch any of the controls on the handheld until you have a couple hundred miles on the engine in a range of driving situations. 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). Commanding the engine to automatically increase speed when switching into drive is a little scary to me though. Tps is saying 26% when it at idle. So, clearly, the "No" answer is wrong. 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. You're going to have to get this fixed or it's going to cause even more problems than the high idle. Camshaft is M-6250-B303 .480 lift intake & exhaust, duration at .050 is 224 degrees for intake & exhaust. To do this, open up the Initial Startup gauge screen that was used in section 17.0. So check that timing and I think that you're going to find you need a good bit of advance. The window you saw in the image above pops up. I can adjust at 160deg, but my fans turn on at 180deg. I drove it a bunch more yesterday afternoon/evening and the same thing happened several times. Your mechanical advance will naturally change the timing a bit but it should be fairly close. Well you were right air was entering from another source. All times are GMT-6. :-). 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! 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. check out the. It is a common one. I can have it working fine (5% to 10% at target idle at operating temp.) The noise is definitely coming OUT of the throttle body. Your comment doesn't imply any sort of problem that would make me give up on idle timing control. They also worked with me on a sale I missed and price matched those parts. 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. Since the shield was put on, not a single problem, not one. Hot start it most of the time wont start unless I give it a little throttle. Having a TPS that won't go lower than 9% will affect the acceleration enrichment correction, and could create a stumble at the first moment of throttle opening.Yes, the IAC can and will fluctuate depending on changing conditions. I have been able to get it pretty This is normally used as an A/C idle-up circuit. 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. If you remove the air cleaner entirely and the whistle continues then you can rule that out. When you experience this, before you touch anything or shut the engine down, first look at your TPS and your IAC. IAC Testing Procedure for EFI Systems It could be a problem with the power/ground for the Sniper but much more commonly this is a result of too much RFI. Perfectif you have the original synchronous linkage. The TPS will go red with a -15 and the AFR reads heating for a split second, then the idle kicks up to 2000RPM. Good luck! Once you have done this the challenge is to create a datalog that includes the ":snap" you describe. Adding a wrap to the return spring on the shaft is one alternative to solving this. I have an entirely separate article on Solving RF Intereference Issues. In the Wizard, select the stock cam setting. Jump on board now! Yes, it will talk to you--but not with words. Throttle Tip-In tuning can be a bit of a challenge but I'm confident you can get this resolved, Mike.Let me start by saying that unless you've really done a lot of driving on the system in some useful learning situations then I would set this issue aside and not even think about it. Sniper EFI offers superior throttle response and wide-open throttle power. Take a drive and stop somewhere for 30 minutes, CTS is 170 when engine was shutoff. idles good, runs amazing. Unfortunately I did not buy my sniper efi from you. I straightened that out, got it running and that's where it goes downhill. IAC Pos.% = 0 This can cause the engine to run rough and may even lead to engine damage. If more info is needed just ask. Ilike a few othersam having idle issues. Cl. The timing can drift 0-30 degrees just due to the width of the rotor tip. Car was running great initially. As inconvenient as it might seem, I'd recommend keeping a timing light handy and checking your timing during the high idle condition and then again after restarting. The on board fuel pressure regulator in the Sniper throttle body has a small filter clipped over one end . The learn function will offset the base fuel table until the closed-loop compensation only requires minimal changes. I followed the instructions and set the IAC to 2-9% when warm with idle at 850 RPM. AGAIN This is Intermittent meaning on a recent trip I stopped 3 times and issued occurred once. Find a lower price anywhere and we'll beat it by 5%! The problem was RF interferance . 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. Sniper EFI Initial Startup and Troubleshooting - Holley My Sniper is 99% great! If the TPS is 1% or below then the ECU is in control--2% or greater and the ECU thinks you've got it under control. If your mixture is too rich, it means there's too much fuel and not enough air. Holley Motor Life There's nothing wrong with manual tuning, but at this point that is just compensating for an inadequate fuel map. I have a Holley Sniper for almost 11 month now and it was running fine with no problems until now. A simple remove & clean will remedy this . These aren't generic newsletters either but instead personalized emails. The broad consensus has been that the Sniper is an amazingly straight-forward install and starts and tunes as expected. Idle > IAC Kick. It didnt do this with the carb on it. 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.