Its rare that you find someone that genuinely wants to help and see something work good, the information I have received from this page and Chris himself is top notch.1969 Dart GT 340 with a Holley Sniper, I purchased the Holley sniper from jegs wish I knew you sold them put on my truck got the IAC set haven't checked the -40 idle setting yet my problem is my headers are glowing red called Holley I think I got the worst person seemed to care less Afr is set at 12.8 for idle only thing I have changed I don't smell any fumes at idle someone said I could change the coolant temp enrichment but I don't know if it is rich or lean I figured since no smell it is lean any ideas would be appreciated thanks i have a fuel psi gauge reads 60 psi don't wanna melt my motor did not glow with a carburetor. About two minutes after I get it set at 850 & 5%, it has progressed to 100%. However, I have never found that to be the case. I do know that the reference angle is 57.5, the inductive delay says 100.0. 680-700.I can't find any reason other than it looses where it is in the firmware with Cheers Darren. IAC Creeps To 100% - Holley Performance Products Forums Well you were right air was entering from another source. i would have been happy to answer there. Laptop Access Closed Loop Compensation rises to 100%, Do I just keep pushing it the same way to My problem is low idle. I'm new to EFI and have no idea what to try next. Target AFR, A / F = 13.5 Thank you in advance for your help and providing us rookies with your I have an entire article on choosing between Sniper and Terminator X throttle body solutions and while Sniper is still a sound choice for some applications, Terminator X (with transmission control) is hands-down the way to go for those who need that. An undersized or partially plugged fuel filter is a classic EFI installation mistake. The Sniper will be controlling the timing so it will be based on a multitude of factors. 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. With the vehicle in neutral, adjust the idle screw until the IAC Position reads between 2 and 10%. It is made by one of the biggest names in fuel filters and sold under the Parts Master label so it is quality and great price in one. I have been reading these posts and have learned a lot. Don't know if I should put this in a separate post. How To Adjust Iac On Holley Sniper I am right back to where I started. I am extremely suspect of what you were told about the Sniper ECU monitoring fuel pressure, for several reasons. After much diagnosis, I ended up replacing the intake manifold gaskets. 2. The "Gauge Text" is what would be shown on a 2-1/16 gauge or the Avenger handheld display. Maybe Holley will add Fuel Prime Multiplier to Terminator X later. The RPM would increase for no reason. 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. EFI Systems based on Holley's world-class Dominator and HP ECU's. Ive had an idle at neutral as high as 2400 rpm. However based on your reply I connected the Fuel Pressure gauge and But they are 100% committed to your satisfaction. Capability Range: Moderate Simply use your handheld controller and go to the Tuning > Advanced > Advanced Idle > Idle Speed screen and click on the Idle Speed Curve function. It only comes back to normal if I turn the engine off and on again. But once you come off the throttle there is a minimum RPM that the ECU wants to see before it releases the IAC from the park position and that is normally 1000 RPM over the target idle. One additional wrap on the secondary coiled shaft spring is all that's necessary. 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. Thanks for any help. As I said above, you could have a bad IAC, but then again, the IAC might be fine and there's a deeper problem such as RFI noise causing the issue or a vacuum leak that is confusing things. Holley Sniper review - The good, the bad, and learn from my - StangNet 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. Does that make sense to you? Tps is saying 26% when it at idle. >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. You will need to change the -40 degree idle speed setting again but I recommend not touching anything else. When this occurs, I sometimes can shut it down and it will return to the correct settiings. He is able to get it to start by quickly depressing the accelerator to at least 60% and releasing. Even at 0% it's sucking a bunch of air through the IAC port. Took it for a lap around the block and came back. Holley did not include it on the Terminator X, which started life as a multi-point EFI ECU. https://www.youtube.com/watch?v=2JpHlS1ymBc, If this is your first visit, be sure to )If you rule out a fuel supply issue then we're going to have to gather a few more clues. Generally, one of two things: a stuck throttle or noise on the TPS signal. One way is to very carefully watch the handheld monitor, and that may be adequate. The small rubber plug had a leak. :-) Just don't let the parts go flying. :-). I, too, wish you'd bought your Sniper from us! 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. This curve runs fom -40 degrees to 260 degrees, and gradually reduces the RPM along that range. Purists will sniff that these are not accurate to the tenth of a PSI. 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. Top 10 Sniper EFI Installation Tips from Holley's Tom Kise Properly configured, the Sniper does a fantastic job of responding to the transition from Park to Drive. So this is my issue ( I did just email Holly). Once you know that then you can work on those problems. May God's grace bless you in the Lord Jesus Christ. Note too that the larger the throttle stab, the more brief the time in that cell and the more gradual the change.Here's what I recommend: Get somewhere where you can repeatedly stop and go. Sniper EFI Problems - Holley Performance Products Forums Seems like its too slow to grab idle when ac kicks on. 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. The first place my eyes go when there is any issue with the idle is to the TPS value. 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. Do you have any clue? I think that the more important point is that Holley kept sending him units until everything was working. idle at 1100 on the "stock" file it's better with street strip.The IAC counts will be at zero. Also what would you say a desired idle should be for a 3 speed automatic ford? % = 49 technical rep said "You ahve high fuel pressure". Don't be surprised if one or the other is slightly open. Thanks! Also ensure the TPS Position returns to zero at idle, & the IAC Hold Position isn't setup too high. While it is not mandatory, I recommend the Sniper EFI CAN-to-USB Adapter to move the data between your Sniper EFI and your PC rather than trying to do this via the SD card. The last 2 times have been shorter and one time the high idle was around 1400, this time around 1100. Commanding the engine to automatically increase speed when switching into drive is a little scary to me though. It could be a couple of things. Ok, so I'm stumped! 63 bomb Pricing was reasonable, shipping was prompt and Chris helped me with a wiring question during my install. The distributor was loose. 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. A problem since day 1 - YouTube Leave a comment if you've had this issue and how you resolved. :-). Once engine is warmed up been driving for awhile. I am at the point where I almost insist that every Sniper EFI System owner purchase one of these. They are prone to be inaccurate. I appreciate everything you are saying. :-). That will happen occasionally, but less as time goes and on and the engine tune stabilizes. Again, I would lean on that solution to let the vehicle drive/learn before you try to "fix" anything. me know how it works for you. Holley Sniper EFI Troubleshooting Mudford Garage 8.6K subscribers 38K views 3 years ago My Bronco with Holley Sniper EFI was running poorly. Covered the IAC port and set idle for 850 ish. It has a lightweight centrifugal spring kit installed so I reach total timing around 2500 rpm. knowledge with the sniper efi setup. Idle when warm was 850-ish and IAC 3-4 just as when I readjusted it the night before. They also worked with me on a sale I missed and price matched those parts. Or is there something else I should You are aware of the idle-up problem. The very first thing I would do is get ground truth on your timing. I'm so glad you found this helpful--that makes my day!Don't get too concerned about the specific learn percentage. A couple of those and you should feel it getting better. Sorta similar to a carb having the idle mixture set incorrectly (rich) or the idle speed too low. I would continue checking the electrical connections along the fuel supply. :-). If not then you have some other issue that is behind this increased idle. We are using Target AFR of 9.0: 1, Fuel Base approximately 40% higher. If your RPM is 2000, your TPS is 0, and your IAC is not closing, then there is some problem. 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. If the connection is loose it will cause the system to shut fuel off because the signal telling the EFI the motor is turning stops (to prevent excess fuel from being dumped in the motor). i'm having is I can't seem to get the truck to run faster than 45 mph at speeds If you drop it too far the engine will stumble or stall when coming off the throttle with the car out of gear, so you'll know when you've gone too far. And yes, monitoring the fuel pressure is the right answer. To figure this out it's going to be important to gather a bit more data. I installed a Holley Sniper on my Ford Maverick 302 V8. 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. 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. I have certainly seen this before on other fuel injected vehicles when hot. Given the circumstances I would say that it is either the IAC motor itself or RFI but you seem to have ruled both of those out. Then do it just a bit faster--just enough for it to bog a bit. I would suggest you take a look at that if you haven't already. Genuine Walbro fuel pumps are virtually bullet-proof. If idle drops below 800 it wont come back itll chug around 300 rpm for a few seconds then die. The AFR was pretty consistent around 13. Can the return line be an issue?So far this sounds like an ideal setup.>I have had 2 faulty gpa-4 255 walbro pumps go bad. 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. The resulting resistance can burn up fuel pumps, wiring and relays. and when I close the IAC's hole with his finger, the engine is normal.The data on the touch screen I see are:AFR, A / F = 35.6 Start by doing the fastest start you can that doesn't bog. While adjusting the screw if the TPS position reads begins to read higher than 0% cycling the ignition switch will recalibrate the TPS back to zero. Setup: 1965 Impala SS; ZZ6 Crate Engine, EFI Distributor. 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!) Your issues are likely related to one of these two things. If you hit the gas it pops & backfires through the throttle body. You advise would be greatly appreciated. Even then, recognize that over time the IAC will need to be readjusted to compensate for minor changes that will cause it to drift. I have a Holley Sniper EFI with HyperSpark ignition. What should I be looking at to calm this down? However I do have a couple of issues I hope you can help me resolve. Then it started behaving oddly. 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. Your second problem should be a bit more concerning. I recently had IAC issues identical to what you describe. is jumping all over the place when you experience this condition, it does not In some cases, you may only be able to put as little as 10 RPM between the hard idle and the target idle. Definitely not 90. Either the Walbro pumps you are getting are not genuine (lots of forgeries being sold) or else you have something that is killing them. Is this normal ? Idle quality is great, RPM is good, sometimes IAC is jumping around from 35 to 60. I will a, Scott has been very helpful and informative on guiding me through the purchasing and installation of my terminator X max system. 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. Find a lower price anywhere and we'll beat it by 5%! Turning it off and back on would reset it, and then it would work as advertised for a while. 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. The throttle plates are misaligned. Thank you. As far as the timing light, I don't know, because I was having problems getting it to work, and that's where I stopped. I have a set of 8.8 Accel Rfi suppression wires on it. 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. Maybe give it a half-turn before you start it and then start and tweak. Wish I knew about it before I made my purchase. To get it to idle the tps is at 2-3-4% even with linkage disconnected and a return spring installed. Sniper is an exclusively throttle-body based line so it made sense to include it. 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. This minimizes installation time and packages really well on a diverse group of engine applications. Doesn't want to start, runs like crap. Thanks again for your insights! Add To Cart. Unfortunately I did not buy my sniper efi from you. Wish I had bought my sniper from you, but unfortunately didnt. 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. Free ground shipping regardless of order size! I was looking at a data log from my truck earlier this week and noted that at idle my IAC was zero. 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 advise would be appreciated. I had HIGH Idle issue and fixing this curve FIXED the ISSUE --- THANK YOUCan you explain what "Current Learn % means, after finally fixing the idle problem this % jump from -1 to -30% in about 5 minutes at idle with CTS @ about 170.Also when starting the car at hot the engine goes to about 2300+ RPM for a few seconds then crashes down to my Hot idle speed of 950 -- bounces a little and then smooths out. I'll bet you find that you can get it working great without any manual tuning. All times are GMT-6. Yes, it will talk to you--but not with words. I' m going to put the 3rd new pump this coming friday. Im in Australia, so stuck the sniper on a 355 Holden engine with CD box. Sniper is still learning so it will continue to improve.Second, you may have heard the phrase, "correlation is not causation." Throttle Tip-In puts you in a part of the fuel map where you stay for only milliseconds at a time. Please let us know how this works out for you! Hey Chris Even though you think your timing is perfect I'd suggest you try cranking about 5-10 degrees of advance into the distributor and just see if that doesn't work better for you.Remember this: adjustable timing pointers go out of adjustment and harmonic balancers slip. Due to when the pump i'm using now makes a loud howling noise when it gets ran for awhile and it gets at a 1/4 tank of fuel or less. 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. The 5-6 times it has happened now have been after the car has been running for at least 20 minutes. Nice to meet you. And your understanding of how the throttle position affects idle is exactly correct. The car would idle, I could hit the gas rev the car up and it ran great I also noticed two nice black spots on my garage floor from the exhaust. The engine has 14: 1 compression ratio, we can not use gasoline. 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. Also, I was seriously rich at idleso rich it hurt your eyes. Jump on board now! 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. Fuel Prime Multiplier is primarily a benefit to throttle-body based EFI systems. Tuning Your Sniper EFI System for Progressive Secondary Link Use I can drive it a bit but pops through the throttle body when pulling out from a stop (4 speed) and sometimes in the exhaust out on the road. At that point the tps is pretty high, then shut the ignition off, pull the tape restart the engine and idle goes into hold mode and idle is through the roof. I took some pics of the sensors page this morning after the car warmed up. So, this is what it takes to put a Sniper on a small-block Ford. One of the signs of a vehicle with a rough idle is a faulty Idle Air Control (IAC) Motor. The timing can drift 0-30 degrees just due to the width of the rotor tip. I've read that a spacer with 4 individual holes will solve this, but after I installed the progressive linkage the noise went away!! Should i adjust idle screw with the fans already on? It appears that I could now use the dongle and a laptop to custom tune for idle issues if needed. At any rate, once the setting was moved up, the RPM jumped right to the target RPM and was solved. port that goes right on the inlet of your Sniper and makes installation a breeze.If your fuel pressure is solid at about 60 PSI then you should start looking at 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. He said they have been having an issue with these lately. Make sure that your blanking level is _below_ that (being careful not to find yourself in the situation I describe above.) Earl's Mechanical Fuel Pressure GaugeI could use that for a quick troubleshooting for 1/3rd the cost of the Holley one. You'll have to go back and forth a couple of times to get it just right. IAC percentage is 5 to 10% when idling with fans on, What you're experiencing is the delay time between the ECU sensing the additional load and the IAC actually increasing the RPM. Hi Chris I didn't get any traction on Holley.com I keep doing that with the same result. I have changed my roc/tps to 7 from 15 but that only took me out of learn mode. I have now determined with the TPS the noise correlates with the opening of the secondary butterflies. If not then I think you are going to find that this will solve much of your problem. So, if pressing the throttle is making it start, it's because you're flooded.Which is consistent with your rich idle condition comment, right? After 50 on the throttle position I'm not sure if the whistle goes away or you just can't here it anymore. The only way to do this is by installing a mechanical fuel pressure gauge. Is there away to lean the idle out? It's a Chevy 350 bored .030" over it has a cam in it what I was told is the cam has the firing order swapped. These are "transitional" cells, and you really have to make the effort to learn in these areas of the map. What would cause the idle to faulter like that? 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. You're going to have to get this fixed or it's going to cause even more problems than the high idle. After only running for about 15 minutes or so the system starts to fail stalling the motor. It sounds like you need a bit more of a fuel squirt on acceleration, Brett. Holley Sniper IAC Problem 04-26-2018, 11:30 AM Hello. This page was generated at 12:25 AM. 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. Perfectif you have the original synchronous linkage. That is the first thing you must find. I installed the Holley gauge you suggested in another thread at the fuel input to the TBI, and the fuel pressure is constant around 64 according to the gauge. Please help. Im thinking a faulty TPS. Hello. The first 250-300 miles were amazing as the Sniper EFI worked flawlessly. Fought a high idle issue until I changed your idle speed curve fix along with dropping the IAC hold to 10%. At some point you come upon problems that evade the easy answers and this is a good example. 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