First thing I would check I did check for the lightning under the hood but all was well. I have not heard of this. If the vendor from whom you bought the system is coming up blank on ideas then don't hesitate to contact Holley's outstanding tech support department directly at 866-464-6553. Clearly, something is changing. Software: Idle > IAC Settings > Idle Spark, Handheld: Tuning > Advanced > Advanced Idle > Idle Spark, After completing this 10-step process, if the temperature displayed on the handheld is still above 160 degrees the engine should go right to it's target. If you have any questions about the car/setup let me know. After speaking with Holley Tech Support and Tech Support from where I purchased the systemthey decided to replace it. Since that has long been corrected we have moved that information to the bottom of the article.). When I put it in park the idle RPM was 2100-2200 each time. Ive had an idle at neutral as high as 2400 rpm. 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. The last pic is with the car in Drive. Should the iac% fluctuate? Holley documentation and videos didn't work and the $300 I paid for "expert" tuning didn't work either. After 50 on the throttle position I'm not sure if the whistle goes away or you just can't here it anymore. And, hopefully, within those degrees you will find a place where you don't get the whistle. I have a bone stock 350 that I installed a Sniper on and had the same whistle noise, presumably from air going past the butterflies. I am new to the EFI scene but want to learn. 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. If it is already adding fuel, it may be worth expanding this into the area where the tip-in is occuring (and where there is no learning occuring. If I cruise down the road at lets say 60 mph and lay into it, she will take off and go. After a complete cool down it will do the same thing. 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. Once it decides to come back down, it does so with no issue. An under-sized filter will allow part- throttle operation but fuel pressure will drop at WOT and run very lean - perhaps surge under power. Changing the rpm curve and target rpm has no effect. The Sniper EFI remote IAC (Idle Air Control) and plug is designed to gain installation clearance on some Sniper EFI 2x4 installations. EFI System Pro had everything I needed for my EFI upgrade. And thanks again for taking your time to answer these questions. 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. engine works beautiful, the car runs a lot, but suddenly, the engine does that. The resulting resistance can burn up fuel pumps, wiring and relays. In your case, however, I think you're close to getting it running. Pw. When I put it in gear, it drops so low that it will stall if I don't add throttle. 30 minutes later CTS reads 161, start engine Idle is jumping from 450 (almost stall) to 1500, IAC is jumping all over 10 90. If the TPS is 1% or below then the air is coming from somewhere else. Holley Sniper IAC | Chevy Nova Forum Well, it turns out that with the current firmware this throws the IAC control into a bit of confusion. I had that problem, right out of the box it would not power up, sent it back in, had defective hand held. 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. I installed the Holley Sniper in my Chevelle this winter with a brand new BluePrint 496. This is actually more troubling than the sound you originally described. The team at Holley has designed the perfect solution for your problems. 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. And Earl's makes a fantastic little 100 PSI gauge. As I would slow down for a stop sign or stop light, the car would run really rough and the idle did not want to come down. Or is there something else I should 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. I have quadruple checked my wiring and am certain it's correct. If you hit the gas it pops & backfires through the throttle body. When you experience this, before you touch anything or shut the engine down, first look at your TPS and your IAC. Hope this helps! around 45 mph it bogs down, catches itself, bogs, catches, bogs and catches. I don't want to go on too long here but once you know if you're trying to add or remove fuel, there are a couple of ways to go. It only lowers to 2-6% when I take my foot off the gas. Even at 0% it's sucking a bunch of air through the IAC port. Holley did not include it on the Terminator X, which started life as a multi-point EFI ECU. i would have been happy to answer there. Well, it sounds to me like your Sniper is doing its best to reduce your idle. I didn't find your site until I was having trouble. Yes its at 95lbs, needless to say he promised a new regulator would be in the By the way, this is a new installation on a 69 Camaro, stock 350, dual sync, etc. My IAC and TPS show zero when it does this. 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. I'll give the ". such high fuel pressure. Turning it off and back on would reset it, and then it would work as advertised for a while. When the lambda is 1.0, the displayed AFR is 14.7;1 REGARDLESS OF THE FUEL. We've already tried adjusting the Acceleration Enrichment chart in all ways, going up and down, RoC Blanking, everything, it has no effect. That way you can get into that part of the table that needs tuning, and you can watch your learn numbers grow. Holley Sniper How To Set The IAC (Idle Air Control) in 5 - YouTube I am right back to where I started. I'm so glad you found this helpful--that makes my day!Don't get too concerned about the specific learn percentage. Thanks for any info./insight you can provide, Mark. If the TPS reading on your Sniper EFI System does not reset to zero that is a problem that needs to be addressed. You might have a bad IAC, but you can also have a bad vacuum pod on the transmission. After doing TPS reset it starts fine but when you give it some gas it hangs at 1500 and will not return to idle. Any help would b great. Don't try to correct for the fuel. I installed Holley Sniper on three other Mavericks here in Brazil and the problem also exists.I did not make any changes to the parameters, only on Target AFR and the correction on the Idle Speed Curve chart. The last 2 times have been shorter and one time the high idle was around 1400, this time around 1100. I can tell you that when things aren't working the way you wanted them to work that nothing beats knowing for-sure that you don't have a fuel supply problem. Hi Chris I didn't get any traction on Holley.com idles good, runs amazing. Interesting question. When I first told him to check for leaks he looked back there and said "all good". I think that your Sniper system is working fine but would definitely check ouf the fuel pump. Holley Sniper Iac Delete If the ECU has not spent some significant time learning yet, I'd recommend going back through the setup wizard and getting everything back to default. Bolt-on carburetor style EFI for your classic car or truck. By the way your site and your accessory products are nice. Does this seem reasonable and how hard will it be to get the idle and off-idle performance correct? Honestly, I've never seen this happen but if the butterflies were misaligned on the shafts it could allow too much air to enter. Okay, try my method. This curve turns the idle speed down as the engine warms. it will jerk and rpm will go up and down and AFR will be around 20 : 1 or more or less. 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. Anyway I have a 327 sbc in a 1987 Monte SS with a T5 5 speed and 3:73 posi rear. Holley EFI 543-105 Idle Air Control Motor 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. 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. 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. But they are 100% committed to your satisfaction. I go into much more detail about that in this article on startup tuning. Simply turn the idle speed screw on the linkage in until the throttle plates open enough for the idle to increase. Im in Australia, so stuck the sniper on a 355 Holden engine with CD box. Tps is saying 26% when it at idle. I haven't driven it for the 30-40 minutes like the several times it idled at 2200. Therefore The iac will always be at 10% now, correct? It is a common one. Did you find this enlightening? Idle when warm was 850-ish and IAC 3-4 just as when I readjusted it the night before. Let 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. You could go either way.. No problems with either cold or hot starts. Then Friday night as I was driving home, the car started acting up. If no air is passing (and the idle doesn't drop) then your IAC is working. Just getting it to act right at startup is a struggle. This is normally used as an A/C idle-up circuit. you have it set. Interesting situation you have. Holley EFI Electronic Fuel Pressure Gauge, article on choosing between Sniper and Terminator X throttle body solutions. If your RPM is 2000, your TPS is 0, and your IAC is not closing, then there is some problem. So this is my issue ( I did just email Holly). IAC Calibration / Hanging rpms | Team Chevelle And if you're going to go this route I'd recommend that you switch from "Simple" (3 A/F targets, one each for Idle, Cruise, and WOT) and go to the 2-D Table Of the two options, I generally recommend the self-learn. Tuning Your Sniper EFI System for Progressive Secondary Link Use Thanks so much for reading! shut truck off. But, if the idle is so high that it is making you crazy then you might try dropping that number just a bit. Hello Chris. Fortunately, Holley has another product that can solve that: Hydramat.. Hydramat is not inexpensive but you won't believe what it can do. That disappears as soon as the throttle is pressed and then you immediately revert to your timing table.You can certainly use the compressor to initate the IAC Kick, but remember that this is just a temporary idle boost to ensure that the engine doesn't die when the AC is first turned on. One of the most common symptoms of a Holley Sniper EFI problem is an air/fuel mixture that's too rich or too lean. Relatively new Sniper EFI install on a '69 Mustang 302. The weather in Ct has finally improved and I have put about 60 miles on the car with the Sniper system. Did your process to adjust idle to 860. Get On The List for Emails Straight From Our Pro? I will a, Scott has been very helpful and informative on guiding me through the purchasing and installation of my terminator X max system. The first thing I'd do is check your fuel pressure with a gauge like this. I recently had IAC issues identical to what you describe. It may take a few tries. 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? Across the board, all of our customers say how impressed they were that it started and ran right out of the box just by following the simple installation instructions. However, I have what I will call a whistle at a throttle position on 35 - 50. 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. 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! I followed the instructions and set the IAC to 2-9% when warm with idle at 850 RPM. If it creates an issue (not normally the case) then you'll know. It's pretty hard to get the header tubes glowing at idle with a lean AFR. The Sniper EFI system looks at the closed-loop fuel compensation required to reach your target AFR. On EFI systems such as Holley's Sniper, all of the EFI sensors (except for the O2 and coolant temperature sender) are mounted snuggly in the throttle body. Cycling the power to the Sniper EFI would cure the problem, but not prevent it from coming back. The data that you provide shows that you have at least two problems. About two minutes after I get it set at 850 & 5%, it has progressed to 100%. All times are GMT-6. Can the return line be an issue?I have had 2 faulty gpa-4 255 walbro pumps go bad. If you have somehow overlooked this, start here: Holley Idle Speed Adjustment Instructions: Once the engine is up to operating temperature, the idle speed can be set to what was configured in the Wizard. The Fuel Base map is perfect, the car works well, runs well, running through the streets, the car is great. Remember that as an EFI System Pro customer you have access to me at any time via my cell phone. Hi Chris, I have a lean stumble on throttle tip in 2-3% tps taking off from a stop light the afr will go to 19afr and the engine will stumble for a split second. Your closed loop compensation is adding a full 50% fuel. I have now determined with the TPS the noise correlates with the opening of the secondary butterflies. I do know that the reference angle is 57.5, the inductive delay says 100.0. The Tech Tips and discussions are also great! Give us a hand! Then it will ramp down to 1200 but will not return to idle. 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. Bolt-on carburetor style EFI for your classic car or truck. If you haven't confirmed that they it is worth checking. Solving RF Interference Issues in Sniper Installations - EFISystemPro.com One additional wrap on the secondary coiled shaft spring is all that's necessary. Im not sure what its doing, have messed with after start fuel, fuel at cranking. That will at least tell you something. Except at idle. Turned it off and on again. Holley Motor Life RPM = 1200My slow gear I leave with 650 RPM, the IAC Position I leave between 5 and 6%, the All times are GMT-6. 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. No power at the programmer and no fuel pump running. Please give this a try and let us know how it works! Now it's at 5% on a big cam 440 Mopar. So glad this was helpful. 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. My issue is that when Im in stop and go traffic, I can let off the clutch and the engine revs and doesnt quite want to come back to idle. Going in the direction you did (higher) is going to reduce the acceleration fueling that the engine sees. )If you rule out a fuel supply issue then we're going to have to gather a few more clues. I appreciate everything you are saying. Also its extremely rich at idle. 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. 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 Then a little faster--until bogs at that level work themselves out. no timing control. I recently detached the TP sensor from the side of the sniper to physically move it and it still would struggle to get to 0%. In the warm state IAC adjusted to a position of 2 to 10%. The noise is definitely coming OUT of the throttle body. We offer some tips to help with that. I think you'll be all set! This is a mighty big subject for a blog post reply, I should probably start doing some videos on this. Sniper EFI Idle Tuning - Holley Motor Life There is no sense proceeding until your TPS is at zero at key-on. My car will now start when its cold, but after about 30 seconds the idle drops down and begins to run like crap. 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. I' m going to put the 3rd new pump this coming friday. When you open your IAC to 30% you are naturally going to have a high idle condition. Until the engine starts, the throttle only has one purpose: To detect you pressing it to 60%, at which point it shuts off the fuel injectors. https://www.gmperformancemotor.com/parts/19210007.html, http://forums.holley.com/showthread.3128#post83128, If this is your first visit, be sure to
Holley Sniper EFI Engine Startup Tuning for Sniper and Terminator X Stealth Owners me know how it works for you. In the context of the Sniper the AFR that is being displayed is the AFR of ethanol-free gasoline based on the lambda that is being read by the AFR. Um, no. Once you so this, and after you have your CAN-to-USB harness attached to your laptop with the Sniper software, you can see precisely the cells where the system is operating when the bog occurs. New install, when in setup wizard TPS says 90 percent and I checked the linkage and butterflies. I recommend confirming there is no throttle linkage issue first. THANK YOU for the "First--Check Your Idle Speed Curve Setting!" If you feel you have no other choice but to run a Sniper and stand-alone controller then you can give this a try. When stopping, the brakes are unable to overcome the engine so I go to neutral just to stop fighting the engine. Car has run perfect every time and has never hesitated or stalled since. Since the shield was put on, not a single problem, not one. When I covered the IAC with my finger, the RPM dropped so low it stalled. But if you can datalog the bog you can know much more precisely what is happening. I have installed my Sniper and the car runs great. When I turn it off and try to restart it just cranks. 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 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). Both Sniper and trans controller grounds were direct to the battery ground, as they should be. I have been reading these posts and have learned a lot. What might cause the TPS to go to 2%? 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. You can adjust this number up or down but there is really no need to change it unless the car is stalling.The sucking sound is just what happens when the Sniper EFI System is paired with certain intake manifolds. Sometimes it sounds like it wants to crank at the start but runs out of gas. Often, folks will say, "I did everything you said. I'll have to check again tomorrow. The biggest issue is these problems are intermittent meaning they do not occur all the time. Note that Brazilian gasoline has 27% ethyl alcohol. Definitely not 90. After only running for about 15 minutes or so the system starts to fail stalling the motor. 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. Not that I noticed. I notice at 2-3% tps the iac is 18-25% and it stumbles, when the iac gets to my hold position of 30 it stops. That is the IAC hold position. I also raised idle at Park a bit with the idle screw. I, too, wish you'd bought your Sniper from us! Again, I would lean on that solution to let the vehicle drive/learn before you try to "fix" anything. Sniper EFI Initial Startup and Troubleshooting Staff Writer 01/20/2020 You can disable the idle spark control at the locations below. It appears that I could now use the dongle and a laptop to custom tune for idle issues if needed. 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. 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. 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.