And the rather cavalier "Absolutely!" Drive great and idles perfect at stop signs. I can have it working fine (5% to 10% at target idle at operating temp.) You can disable the idle spark control at the locations below. You have to remove all hoses in order to debug the problem. Check the Distributor Tach Connection to the EFI. IAC Testing Procedure for EFI Systems The broad consensus has been that the Sniper is an amazingly straight-forward install and starts and tunes as expected. Okay, try my method. I have an entirely separate article on Solving RF Intereference Issues. Yes its at 95lbs, needless to say he promised a new regulator would be in the I emphasize "and" because the transmission controller manufacturer I used had the TPS ground terminated within the harness to the unit's main ground, which I find to be an unthinkable choice. To keep it running in gear, I have to bump the neutral idle up just over 1000 RPM. Enjoy! A problem since day 1 - YouTube Leave a comment if you've had this issue and how you resolved. My Sniper is 99% great! Was perfect idle iac reading 3. 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. If I try and get the 2-10% i get all the way up to 1200 rpm. Then you can take a close look at the IAC and see if it is opening. Yes, it will talk to you--but not with words. It will learn the fueling eventually either way, it's just that one might get you there a little faster.If the idle is fine at start-up but then increases after you depress the throttle then you might need to lower your IAC Hold Position a bit. I was looking at a data log from my truck earlier this week and noted that at idle my IAC was zero. It has a lightweight centrifugal spring kit installed so I reach total timing around 2500 rpm. 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. your IAC is at zero. Price Point: $$$. This is very disappointing as people love to hear the motor while the hood is open.Thanks Jon. This is normally used as an A/C idle-up circuit. 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. To finish, I rather tightly twisted the TPS signal and ground wires all the way from the controller to the Sniper TPS and very carefully routed them away from sources of RFI. May God's grace bless you in the Lord Jesus Christ. Simply use your handheld controller and go to the Tuning > Advanced > Advanced Idle > Idle Speed screen and click on the Idle Speed Curve function. Explained: Holley EFI Sensors and What They Do I certainly appreciate your frustration (as well as your wife's!) When I drive with warm engine the IAC is at 30% when pushing gas, but shouldn't it be at 0%? I believe because the TPS is not registering. While you have over 200 miles on the system, you must realize that in the part of the map where the ECU finds itself during lanches you might only have a total of 5-10 seconds in any given cell. I asked him a million questions and waited a long time to save up before purchasing the system and I have asked a lot of questions throughout the installation process. Installed sniper on 65 galaxie. 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 I have driven car about 200 miles. Yes, having an accurate TPS is very important at idle. First, check to make sure that the IAC is properly mounted and connected. i'm having is I can't seem to get the truck to run faster than 45 mph at speeds Hello, Chris, thanks for the help.I have not installed the software yet, and I'm having trouble with two cars. Could be a bad IAC motor, replace it and see if that solves the problem. At some point you come upon problems that evade the easy answers and this is a good example. The small rubber plug had a leak. Holley documentation and videos didn't work and the $300 I paid for "expert" tuning didn't work either. Sorry I didn't buy from you but I didn't know you had sold them. $107.95. Camshaft is M-6250-B303 .480 lift intake & exhaust, duration at .050 is 224 degrees for intake & exhaust. The whole topic of using the Sniper TPS for transmission control is one deserving of it's own article but I'll try to summarize a bit here. The last pic is with the car in Drive. Clearly, something is changing. The distributor was loose. The fix? Incorrect connections will result in excessive resistance. My primary reason for going EFI was drive-ability, (Startup and take off without waiting for the engine to warm up) and not have the occasional hesitation a carburetor has especially just barely opening the secondaries. Every time though I can turn the car off and restart and it settles at 850 with IAC 2-4.The thing that has me puzzled is how the with the only difference in condition of the car being the restart, the idle is "fixed"Any clues on where to look next please let me know. Earl's Mechanical Fuel Pressure GaugeI could use that for a quick troubleshooting for 1/3rd the cost of the Holley one. 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. Only show this user . Am I missing something. 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. Is that normal? It then started working normally again. I go into much more detail about that in this article on startup tuning. Worst case you'll have a spare on hand, and if the TPS is faulty you will have solved the mystery. Were the additional load a simple step function it would be challenge enough for the ECU to gracefully increase the engine speed without overshooting. The next time it happens is the perfect opportunity to find the problem. datsun sniper efi Holley RetroBright This 1974 Datsun 620 Bulletside Cruises With The Help Of Sniper EFI Bradley Iger 01/13/2023 features Latest News sweepstakes 2023 Hemi Engine Sweepstakes Gen III Hemi Enter To Win Holley's 2023 Hemi Engine Sweepstakes For Your Chance To Win A 600+ Horsepower 392 Stroker! other things that might cause the idle to faulter, but this is a good start. Learning to install these is great--you're about to embark on the next great adventure of advanced troubleshooting. around 45 mph it bogs down, catches itself, bogs, catches, bogs and catches. Is this normal ? If you have performed the adjustments above and still have RPM issues, it's time to look for clues. Don't make any changes more than about 10% and keep the same basic shape as the original (High/flat below 20 degrees, sloped downward up to 180 degress, and then flat again above that.) I think that your timing is too retarded. Chris thank you for the info. Engine warms up to 195 degrees and stays. If you have an installation or start-up issue that is nagging you then please use the comments section to reply and we will gladly provide more information that we hope will be useful to you. The timing can drift 0-30 degrees just due to the width of the rotor tip. The problem I'm having is I cant get the IAC to drop down off 100%. 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. Repeat until that stumble goes away, and then try a bit more throttle. It will need to see it again and again. You've got it running and warmed up but now you need to set. Thanks for any info./insight you can provide, Mark. Cycling the power to the Sniper EFI would cure the problem, but not prevent it from coming back. 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. One of the best Ive seen so far. Or alternator? Please advise. Since the shield was put on, not a single problem, not one. I installed another return spring for the rear plates problem solved instantly. If they are closed, check the primaries. If you don't have a working coolant temperature sensor then it will never bring the idle speed down. 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. 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. This will let you know at a glance if something is going awry with the fuel pump. Thanks. :-). Supports up to 650hp with Four 100 Lb/Hr Injectors! You can manually set it 57 after you run the Wizard if required. 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. You are aware of the idle-up problem. 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. After pumping the pedal a few times at different times it dropped to zero and started to work. 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 I'd recommend you contact Holley Tech support to get their input (1-866-464-6553; call early for the shortest wait times.) % = 49 If you haven't installed a Consider adding fuel in the AE vs TPS and/or AE vs MAP ROC tables in the area where the stumble is occuring.Since this is happening at such low TPS levels it is possible that your engine would prefer a lower (richer) target AFR number at idle. Engine Startup Tuning for Sniper and Terminator X Stealth Owners engine works beautiful, the car runs a lot, but suddenly, the engine does that. I started with right after I first adjusted for 2% IAC and took pics about every 30 seconds over about 2 minutes. Two things to keep in mind as you do that. I'm new to the efi thing and any help would be seriously appreciated. shut truck off. I keep wondering how it was running so good with The learn function will offset the base fuel table until the closed-loop compensation only requires minimal changes. If not then I think you are going to find that this will solve much of your problem. I have driven it a few times maybe 100 miles or so. (Note: in the original version of this post we had a section about checking the idle speed curve setting. The Fuel Base map is perfect, the car works well, runs well, running through the streets, the car is great. (I'm running from a fuel cell on the garage floor 10 feet away with lines in plain sight and do see fuel coming from the return at a decent flow. idles good, runs amazing. Capability Range: Advanced 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. Or ?I have put a fuel pressure gauge right at the inlet of the sniper and it is reading 60-64 psi. If I read it correctly, the solution from the other thread seemed to fix a constant 300 or so RPM increase. 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 have been able to get it pretty If it is not a problem with the Sniper EFI System itself then it could be an issue with some sort of harmonic involving the fuel pump. Even at 0% it's sucking a bunch of air through the IAC port. installing and cruising down the highway 70 mph I just wonder if all I have to do I appreciate everything you are saying. I'll give the ". We're having trouble with a Ford Maverick 302 V8, using ethanol. Hello Chris. Bolt-on carburetor style EFI for your classic car or truck. 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. Wish I had bought my sniper from you, but unfortunately didnt. 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. Use the idle speed screw to set the idle at a comfortable warm-up speed. that my Air/Fuel ration was 15:1 and I believe the target is 13.5:1. This is actually more troubling than the sound you originally described. 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. Going back to what you said. After much diagnosis, I ended up replacing the intake manifold gaskets. Yes, it will talk to you--but not with words. The Sniper EFI remote IAC (Idle Air Control) and plug is designed to gain installation clearance on some Sniper EFI 2x4 installations. 90% of problems, (INCLUDING MYSELF) could be answered/fixed by just reading the instructions. 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. When you first posted this I had no idea how to respond. Sniper EFI Problems - Holley Performance Products Forums I have replaced the IAC motor and the problem remains. I did read some comments on regulator issues is there a way to check it for an issue ? :-). A couple of possibilities that come to mind in order of likelihood: Im having an issue with what I think is the Iac. If your mixture is too rich, it means there's too much fuel and not enough air. Why is this? The team at Holley has designed the perfect solution for your problems. Once you've done this, the next natural step is to transfer the learn table to the base map, then go in and smooth out the sharp edges, which are going to be at these transitional states. Holley have given a new unit. In your case, however, I think you're close to getting it running. They are prone to be inaccurate. EFI Systems based on Holley's world-class Dominator and HP ECU's. Price Point: $$, EFI Systems based on Holley's world-class Dominator and HP ECU's. 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 latest was changing the power brake booster.Today I drove it to work and no issues at all. Throttle body mounted ECU - no extra boxes to mount. But, if the idle is so high that it is making you crazy then you might try dropping that number just a bit. Good luck! My car will now start when its cold, but after about 30 seconds the idle drops down and begins to run like crap. Sniper EFI offers superior throttle response and wide-open throttle power. = 2.34 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. Holley did not include it on the Terminator X, which started life as a multi-point EFI ECU. 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. 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'd suggest that you assume everything the previous owner did was wrong until you can prove that it was done correctly. Idle when warm was 850-ish and IAC 3-4 just as when I readjusted it the night before. This happens no matter how much I adjust the idle screw. If you complete the process and find that the IAC is less than 2% at idle, repeat the process and use the set screw to make the RPM about 60 RPM below the target. But if you will just advance the timing at idle and see if it makes a difference then that will tell you what you need to know. Holley Sniper IAC Surging???? A problem since day 1 - YouTube The IAC going to 30 is normal. I did change the -40 thing also. It only lowers to 2-6% when I take my foot off the gas. The ticking is inline with the fuel pressure I feel squeezing both the fuel return & delivery lines (like a heartbeat). Key, I believe, in this success is solid connections, resistance-free signal and ground paths, and solid RFI rejection. 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. Hang in there--you can do it. Chris's Idle Speed Adjustment Instructions*: *Note: If you are using your Sniper to control ignition timing then I recommend that before you start this process you disable idle spark control If you are trying to do this while the ECU is simultaneously trying to bring your idle under control by adjusting the advance it is going to be counter-productive. Good ps. I, too, wish you'd bought your Sniper from us! Genuine Walbro fuel pumps are virtually bullet-proof. I then saw you guys have an awesome little gauge that can hookup inline to the snipers existing fuel feed?? I received from the controller manufacturer greatly understates (at best) the repeated failures of others I know personally who have tried and failed. Is there any chance that your timing has changed since you installed your Sniper? And Earl's makes a fantastic little 100 PSI gauge. i would have been happy to answer there. If you do find you have RFI issues then I've written an article on solving RFI problems. I have turned ignition off turned screw in 2 turns and turned ignition back on and tps is at 1-2% not sure whats going on. Comp. I also raised idle at Park a bit with the idle screw. So glad this was helpful. The Sniper resets the TPS to 0% each time that you key the system on. I have a set of 8.8 Accel Rfi suppression wires on it. Very annoying ended up being simple my rear plates would stay open constantly it was driving me nuts I'd let off the pedal idle at 1300 blip the throttle a few times finally come back to 850. At 0% it shouldn't be sucking any air through that port, correct? A simple remove & clean will remedy this . Even at 0% it's sucking a bunch of air through the IAC port. If you've been running a filter then you have to wonder if you have a legitimate Walbro pump.If you install a new pump and the noise is still coming from the Sniper EFI System then only the dealer who sold you your system can help you. You will have to do this until the TPS stays at 0% when the throttle is closed. (It should be at or near 60 PSI at idle. 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. Try it! Jump on board now! I have a Holley Sniper for almost 11 month now and it was running fine with no problems until now. Your suggestion to remove the PCV valve is just for diagnosis purposes, right? Hello Chris. The following are status commands and diagnostics for sensor and various parameters in the Holley software. I have a Holley Sniper for almost 11 month now and it was running fine with no problems until now. Thanks so much for reading! WIthout knowing quite a bit more it will be more than challenging for you to identify the problem and solve it.Fortunately, Holley provides their amazing Sniper Software. I figured out I was going the wrong direction when I was messing with the AFR programming. After a complete cool down it will do the same thing. The idle will not return to the set value.The second issue is the same as the first but the motor will stall out. Holley Sniper EFI Problems: Best Fixes According to Manufacturer By the way your site and your accessory products are nice. That's what you're seeing. I have a Holley Sniper EFI with HyperSpark ignition. I called support line he said he would have to look into it and call back. Common killers: No filter in front of the pump, reverse wiring, driving with PWM voltage, running at dead-head pressure.Since it sounds like your pressure is right, and since the Holley system doesn't provide a PWM voltage, that pretty much rules out everything but the lack of a filter. )If you rule out a fuel supply issue then we're going to have to gather a few more clues. 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. The engine ran so good, I would have never suspected the Fuel Pressure to be an Pricing was reasonable, shipping was prompt and Chris helped me with a wiring question during my install. I did buy the Sniper from you guys and the service was fantastic. If the engine will after the 4 seconds that the IAC kick drops off then it's not really going to help.At any rate, it costs you nothing to advance the ignition and see if that doesn't improve the idle, right? If it is then something is commanding the ECU to open the IAC. I've tried repeatedly re-creating the scenario in hopes that the E.C.M. In this short video you learn to replace the IAC. Your AFR is pegged lean. Yes, the sound coming out of your Sniper throttle body is a pulsation from the fuel pump that is pulsing the mechanical fuel pressure regulator. ChrisI finally got everything resolved. the gas it catches itself and runs fine at slower speeds. You will need to change the -40 degree idle speed setting again but I recommend not touching anything else. Data logs show no EMI/RFI. (Grease can sometimes do the same thing as a more permanent gasket sealer without making the removal of the air cleaner such a pain.). It runs perfectly fine other wise. If you go the other way then you might find that the IAC zero's out when the fans are off. So what--you're never going to drive in minus 40 degrees, right? The Street/Strip and race cam setups tend to be too rich initially. Be sure to re-enable it once you get your idle tuned. TPS 0. Then do it just a bit faster--just enough for it to bog a bit. !I called Holley today, and before I could even described the symptoms the Inj. Once it commands that high idle I haven't found anything to return it to normal, other than shutting it down and restarting. Definitely not 90. idle counts from 0. Holley sniper, bogging/ losing power "NOW FIXED" Add To Cart. Mechanical Fuel Pressure Gauge on the inlet of your Sniper, now is the time. My IAC and TPS show zero when it does this. So something is triggering the ECU to be in Open Loop. One thing you need to sync the timing and set the inductive delay. I straightened that out, got it running and that's where it goes downhill. The data that you provide shows that you have at least two problems. 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. Holley Sniper EFI Interesting situation you have. About two minutes after I get it set at 850 & 5%, it has progressed to 100%. Holley EFI 543-105 Idle Air Control Motor