idle at 1100 on the "stock" file it's better with street strip.The IAC counts will be at zero. The biggest issue is these problems are intermittent meaning they do not occur all the time. Those little 1/8 NPT gauges are pretty inexpensive and generally pretty easy to find locally.If you confirm that the pressure is indeed 90 PSI you could pull the fuel pressure regulator apart and check it. Well, it turns out that with the current firmware this throws the IAC control into a bit of confusion. 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. I will turn it up some more.Is this something that the ECU will learn? It didnt do this with the carb on it. The tps will not auto reset to zero. In the wizard I set my Idle to 500RPM but it never got slower than 800RPM, if I run the wizard again and lower to 400 RPM then it never gets lower than 700RPM.After reading about the Idle Speed curver I checked its settings and found that the curve was 300rpm faster at every point over the temp range no matter what temp I had, I adjusted the curve to match what I put in on the wizard and now the RPM is correct, I'd say you have a bug in the wizard.Idle Speed > Idle Speed Curve: Here is where the lack of coolant temperature is going to affect you. Holley Sniper EFI Troubleshooting Mudford Garage 8.6K subscribers 38K views 3 years ago My Bronco with Holley Sniper EFI was running poorly. The TPS will go red with a -15 and the AFR reads heating for a split second, then the idle kicks up to 2000RPM. 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. Using the handheld, navigate to Tuning > Basic > Basic Idle and ensure your target idle speed is set to the RPM you desire. 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). Also when ac kicks on it will idle down and stall. If the IAC number is increased during this high idle, review the points about high idle from tuning issues. Thank you in advance for your help and providing us rookies with your And so glad you guys are enjoying the Sniper EFI system. Once engine is warmed up been driving for awhile. Now it registers zero and I have good idle but it will not register until it hits 60 and up. Resistance results in heat and heat results in more resistance. Therefore The iac will always be at 10% now, correct? I appreciate the help youve given to everyone as it continually helps me! The first 250-300 miles were amazing as the Sniper EFI worked flawlessly. Pricing was reasonable, shipping was prompt and Chris helped me with a wiring question during my install. 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. Reducing that a bit will help. 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. I managed to get the IAC down to around 0% - 8%is this good? My problem with the sniper is the whistling and hard throttle pedal, I have a 700r tranny with a kick down cable. Thanks so much for reading! If there is an issue with using the Sniper EFI TPS signal, is there a remote TPS or an adaptor for the Sniper EFI that allows the TPS signal to be accessed for the transmission. I keep wondering how it was running so good with = 2.34 Then, when you experience the high idle, note if the IAC number has increased. If you get into the practice of hearing all three of these sounds you will know if you have a problem even before you turn the key to crank. I have a Holley Sniper for almost 11 month now and it was running fine with no problems until now. As always, I recommend great restraint in changing any of the parameters until a significant amount of learning has taken place. My car will now start when its cold, but after about 30 seconds the idle drops down and begins to run like crap. % = 49 These problems will go away when you do that. I have a Holley Sniper EFI with HyperSpark ignition. Have a look--I think this is going to allow you to fix your idle problem. Thanks for all your help Chris! I chased that gremlin for about three weeks and was convinced I had a bad throttle cable. 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.) When I see that your TPS is 1%, that tells me that you may have an RFI problem. If you feel you have no other choice but to run a Sniper and stand-alone controller then you can give this a try. Is this normal ? I ask because I'm using a PCV valve with my Sniper and have random idle issues as well. 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. Closed Loop Compensation rises to 100%, Do I just keep pushing it the same way to I cut and heat-shrink wrapped the 5V wire and then ran both the signal and ground wires all the way back to the transmission controller. If you go too low then it may stumble or even stall when coming off of throttle. I pulled over and turned the car off and then back on. (Do this while you are cranking.) At some point you come upon problems that evade the easy answers and this is a good example. 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. Several good bits here. Full product line and accessories at excellent pricing. Going in the direction you did (higher) is going to reduce the acceleration fueling that the engine sees. That is what I really respect about Holley. First thing I would check I've helped folks work through a number of challenges with their Sniper EFI System installations. Target AFR at idle is 13.8%. Idle was back to normal but iac was at 0. This is normally used as an A/C idle-up circuit. First, recognize that the IAC and the TPS are not inter-related in any way. 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%. 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? Learning to install these is great--you're about to embark on the next great adventure of advanced troubleshooting. 90% of problems, (INCLUDING MYSELF) could be answered/fixed by just reading the instructions. So if you are trying to achieve a stoichiometric mixture in ethanol (which is achieved at an AFR of 9.0:1) then you should continue to target 14.7:1 since that is what will be displayed. Overview. I also raised idle at Park a bit with the idle screw. I started with right after I first adjusted for 2% IAC and took pics about every 30 seconds over about 2 minutes. The jack-rabbit start can usually be minimized by adjusting the throttle linkage. Two things to keep in mind as you do that. This happens no matter how much I adjust the idle screw. I have probably 200 - 300 miles on this engine and it has always done this. That is not a huge problem but it just means the IAC has no ability to lower the idle beyond what it is running at that point. 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. 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. I readjusted my IAC, now it's perfect. Two months fighting, cursing, not getting any help from Holley OR the forum, and a stupid little tin plate. It could be that you've left a vacuum port unplugged, it could be that the throttle plates are misaligned (unlikely), it could be that your IAC is not closing properly. Don't try to correct for the fuel. The data that you provide shows that you have at least two problems. applies here because it is so important to realize that just because the IAC is jumping all over the place when you experience this condition, it does not One additional wrap on the secondary coiled shaft spring is all that's necessary. Now that you've installed at least four Snipers it is going to be imperative that you learn to create and read datalogs. 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. 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. Duration @.050 is 240 intake 246 exhaust with .574/.578 lift. Also if I give it a During cruising at 30 miles and release the gas pedal the engine revs at aproximaly 1500 RPM and it won't drop. Its just at low speeds, not sure if its loading up or leaning out. If you go too high then the motor will not return to your target idle when you come off the throttle. I drove it a bunch more yesterday afternoon/evening and the same thing happened several times. 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. Hi Chris. We have never had that problem with any of the units that we have shipped. You have to remove all hoses in order to debug the problem. It works instantly for him.If that fixes your problem then you have a starting place. Turning off and then on again, the engine returns to normal. 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. You are looking in the right area but I would probably not change the ROC blanking. I will try the other stuff when I get off work. Without it you are working in the dark. 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 first place my eyes go when there is any issue with the idle is to the TPS value. The hold position is part of the response that keeps the car from dying when you come off the throttle. 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. 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. The Sniper EFI system looks at the closed-loop fuel compensation required to reach your target AFR. I will confirm TDC with balancer but I have had balancer off and timed it before and after with same results. It could be a problem with the power/ground for the Sniper but much more commonly this is a result of too much RFI. I did all of this before seeing the link you sent. To do this, open up the Initial Startup gauge screen that was used in section 17.0. The Sniper resets the TPS to 0% each time that you key the system on. Sorry for all the questions, new to the efi world. The team at EFI pro are some of the best I have ever dealt with when coming to ordering parts or having the knowledge to answer any question you may have. Fortunately, these are much easier to solve. Try it! You could go either way.. The Sniper ECU can use the timing to help maintain the idle speed and that will definitely be useful in that transition from Park/Neutral to Drive.If you don't have ECU-controlled timing, or if you do and it's not fully compensating, it may be necessary to increase your target idle slightly. Your issues are likely related to one of these two things. no timing control. ?I never had my Carb Cold start RPM any higher then 1600 RPM.THANK YOU. All times are GMT-6. Handheld shows plenty of fuel so I dought it's an issue there. These aren't generic newsletters either but instead personalized emails. I did notice that when I thought I had it set If I try and get the 2-10% i get all the way up to 1200 rpm. I've changed all the If the IAC is zero, and if putting your finger over the IAC port doesn't lower it, then it's not the IAC circuit. See these. :-). I' m going to put the 3rd new pump this coming friday. Idle : IAC Rampdown : IAC hold positionChange this by maybe 2% in either direction. If I go any more it will ping. I did read some comments on regulator issues is there a way to check it for an issue ? first attempt but as it tries to idle down to the target RPMsit can never even Once it commands that high idle I haven't found anything to return it to normal, other than shutting it down and restarting. shut truck off. I would continue checking the electrical connections along the fuel supply. Hopefully replacing the pump again will resolve both issues. The headache is the Acceleration Enrichment. There are two ways to address this--you can let the system learn or you can manually adjust the acceleration enrichment. Once you confirm the operation of your IAC then it's time to read my article on Solving RFI Problems. I installed my Sniper and the engine fired up great. Doesn't want to start, runs like crap. Replacement Idle Air Control (IAC) Motor for Sniper EFI TBI Systems, Sniper 90/92/102mm Throttle Bodies, Terminator TBI, Avenger 4bbl TBI, HP 4bbl TBI, Commander 950 & Digital Pro-Jection Systems. TPS 0. 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. :-). I got it home, checked it all over, everything is hooked up correctly. Always had to set idle above 950. The "Gauge Text" is what would be shown on a 2-1/16 gauge or the Avenger handheld display. Observing the temperature on the 3.5-inch handheld (only), wait for the temperature to achieve 160 degrees F. Once above 160 degrees, turn the idle speed screw so that the idle is about 50 RPM below your target idle speed set in step 1, above. 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. One thing you need to sync the timing and set the inductive delay. 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. Now, 1% on the TPS isn't a problem, but when it goes to 2% (which is inevitable if you have RFI moving it to 1%) then the IAC is going to go to it's hold position (30% by default) and the engine is going to rev up. So I had my Idle set up perfect, with idle timing control off and engine hot the IAC was right at 2-4%. mail today. I installed a sniper efi system on my 1969 Camaro. First, let me congratulate you on your patience in letting the system learn. Chris---I am contemplating replacing my Holley 750 on my new low vacuum 600 HP 496 with the Holley Sniper FI system. Chris, I recently installed my Sniper and have an intermittent idle problem. I am Japanese who attached Sniper EFI. Your task will be to find that. Otherwise, if removing the air cleaner eliminates the whistle then try to use a thicker gasket or try lightly greasing the gasket. But there are several degrees of play there in which it should still work fine. 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. If you are using your Sniper EFI System to control timing, navigate to Tuning > Advanced > Advanced Idle > Idle Spark and ensure that the Idle Spark Enabled is set to Disabled. Thank you for this guide on setting IAC. 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. 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). 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. Thanks. You can manually set it 57 after you run the Wizard if required. Give that a go and see if you don't make some progress! I' m going to put the 3 rd new pump this coming friday. What might cause the TPS to go to 2%? This will let you know at a glance if something is going awry with the fuel pump. It then idles up from 750 to 1100. would correct it (as it has for a multitude of other drive-ability issues) but this one little glitch seems out of it's range. engine works beautiful, the car runs a lot, but suddenly, the engine does that. :-)Yes, learn impacts idle too, and remember the even when the basic learning is done there will continue to be some learning for changes in weather, altitude, etc.Go ahead and try a few idle settings and see how they impact the idle-speed searching. RPM = 1200My slow gear I leave with 650 RPM, the IAC Position I leave between 5 and 6%, the )Take a look at your AFR during the starting process. I then saw you guys have an awesome little gauge that can hookup inline to the snipers existing fuel feed?? 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. Everything was working perfectly and I shut off the engine. But I am having troubles.When stepping on the accelerator slightly with idling, it will be 2000 RPM all the time. Do please let us know what you find out! So, clearly, the "No" answer is wrong. Purists will sniff that these are not accurate to the tenth of a PSI. If I adjust idle screw out to get the tps to zero or even 1% the engine will not idle. I've not heard of any others with this exact issue so I don't think it is a common problem. I recently install a sniper efi. It is a common one. Also its extremely rich at idle. Give it a watch: https://youtu.be/7SO7-tZn6iw. Capability Range: Advanced As you have noted, each time the idle goes up. Just getting it to act right at startup is a struggle. Wish I knew about it before I made my purchase. However, I can't think of a single one that was because of low vacuum. I can get it to fire up on the The throttle blade adjustment is at 2-6% at hot idle, and with warm engine 185F. If they are closed, check the primaries. FYI: Car is a 1970 Mustang 302 Ford Racing roller motor. I have an adapter on the manifold for squarebore to spreadbore and then a phenolic spacer. Its on a big block Mopar with stock electronic ignition . Just thought I'd ask as there isn't a lot of info out there. 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! Turned it off and on again. This increased idle speed is triggered by grounding the orange wire in the 10-pin I/O harness. 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. 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. The team at Holley has designed the perfect solution for your problems. Fortunately, I have an article that goes into this in some detail. Inj. it will jerk and rpm will go up and down and AFR will be around 20 : 1 or more or less. But after sitting static idling for a little bit, the IAC goes to 100% & stays there. The broad consensus has been that the Sniper is an amazingly straight-forward install and starts and tunes as expected. The idle will not return to the set value.The second issue is the same as the first but the motor will stall out. I would disregard any correlation between idle control between the Stock and Street/Strip setups. back upthe RPMs shoot up to anywhere between 1500 and 2000 and they will not get NOTE: Do not attempt to set the target idle speed and IAC position until the engine is above 160F! The 5-6 times it has happened now have been after the car has been running for at least 20 minutes. 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. Please let us know how this works out for you! How can I adjust the startup speed down to about 1400 RPM? other things that might cause the idle to faulter, but this is a good start. If the solutions suggested above are not working then you need to review my article on IAC Testing Procedures. It really takes a lot of throttle tip-ins before you get anywhere near "learned" in this part of the fuel map.Based on your description, it sounds like you have a lean stumble. I used the Casper's Electronics 108103 splitter and carefully soldered my connections. Now I have most of the bugs worked out it runs fine on the highway and around town it's just the idle. I have checked the pink wire and it is at .001 volts when key is off. If i set the idle to 750, the only way i can get it there is to turn the idle screw all the way out but then its at 0 iac. I called support line he said he would have to look into it and call back. Yes, it will talk to you--but not with words. 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. Unfortunately I did not buy my sniper efi from you. The Street/Strip and race cam setups tend to be too rich initially. Another suggestion is to add an extra turn to the spring built into the linkage to increase the closing force on the throttle shaft. To be honest, you sound like an ideal candidate for Sniper ECU ignition timing control. Initial Baseline Idle Speed Screw Setting, http://forums.holley.com/showthread.neral-IAC-Info, http://documents.holley.com/199r11031r.pdf, https://forums.holley.com/showthread-Idle-Solution, If this is your first visit, be sure to This is very disappointing as people love to hear the motor while the hood is open.Thanks Jon. That's not the IAC Hold Position, it's a percentage value. But before you adjust the ECU to lean the idle out, first confirm that your fuel pressure is right. 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. Do you have any clue? 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. Repeat until that stumble goes away, and then try a bit more throttle. Holley Sniper IAC Surging???? I have been reading these posts and have learned a lot. I'd recommend you contact Holley Tech support to get their input (1-866-464-6553; call early for the shortest wait times.) If you hit the gas it pops & backfires through the throttle body. 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! Or is there something else I should MAP Sensor. :-DStill, I hate to leave someone hanging so I'll try to help. Hang in there--you can do it. Bryan McTaggart 02/28/2023 news The very first thing I would do is get ground truth on your timing. any advise would be appreciated. idle counts from 0. But another thing to consider is adjusting your target A/F ratio. Have you confirmed your fuel pressure at idle is 60 PSI? My car will not idle right until it gets to around 130 -140 degrees. 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.