holley sniper efi iac problems
You are looking in the right area but I would probably not change the ROC blanking. As you see above, the Sniper is going to dump in a maximum amount of fuel at zero TPS, begins to remove acceleration enrichment at 60 percent TPS, and then removes all acceleration enrichment correction at 100% TPS. One of the signs of a vehicle with a rough idle is a faulty Idle Air Control (IAC) Motor. 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. 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). Good luck! It may take a few tries. The IAC going to 30 is normal. 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. 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. However, whenever you start changing things, you can get into a chain reaction. ?I never had my Carb Cold start RPM any higher then 1600 RPM.THANK YOU. )Then look a the datalog and find out what TPS ROC and MAP ROC is most likely to cause the problem. Don't try to correct for the fuel. Any help would b great. :-)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. These are "transitional" cells, and you really have to make the effort to learn in these areas of the map. It only lowers to 2-6% when I take my foot off the gas. The Super Sniper will allow you to monifor fuel pressure if you add an electronic sender but this is not an option with the standard Sniper. Chris, I recently installed my Sniper and have an intermittent idle problem. That's not the IAC Hold Position, it's a percentage value. Unfortunately I did not buy my sniper efi from you. 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. Lubricate the linkage so there isn't as much native resistance. :-). I know its not flooded because I can pour a little gas in the throttle body and play with the accelerator and it will start and run fine. IAC is good 0-5% most of the time. 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. It is simply for the benefit of the user. Start engine let it warm up to 160, learn mode is learning. It'll start & run till it's warm, then when I try setting the IAC every time, I try getting it between the 2 & 8% it quits. Hi. Any suggestions would be appreciated. There are six different acceleration enrichment tables that you can tweak and that may be the way to go. So as much as I can I have been taking off real slow and let it fall on itself to try to learn and its not learning its way out of it. back upthe RPMs shoot up to anywhere between 1500 and 2000 and they will not get Comp. Hello Chris. They are prone to be inaccurate. Possibly cap, rotor, coil? I'm Having trouble with the Sniper on high Idle. At some point you come upon problems that evade the easy answers and this is a good example. May God's grace bless you in the Lord Jesus Christ. 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.) Have a look--I think this is going to allow you to fix your idle problem. 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. Is that normal? it seems to ramp to 60 psi on the initial prime, but as soon as the motor start the psi spikes.I guess a workaround would be an inline return/filter regulator? You've got it running and warmed up but now you need to set. 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 a bone stock 350 that I installed a Sniper on and had the same whistle noise, presumably from air going past the butterflies. I'm new to EFI and have no idea what to try next. 63 bomb The Sniper EFI system looks at the closed-loop fuel compensation required to reach your target AFR. Hey Chris Turned it off and on again. I will let you know what the results are. Idle : IAC Rampdown : IAC hold positionChange this by maybe 2% in either direction. Idle quality is great, RPM is good, sometimes IAC is now between 2 and 5 exactly where it should be. Don't be surprised if one or the other is slightly open. Simply use your handheld controller and go to the Tuning > Advanced > Advanced Idle > Idle Speed screen and click on the Idle Speed Curve function. This is actually more troubling than the sound you originally described. Thank you. Yes, you are correct. If you find that the IAC is more than 8 percent, repeat this process and instead of shooting for 50 RPM below your target make it only 40 RPM below the target idle speed. 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. If I were there in person I would test the function of the IAC (see this article.) And thanks again for taking your time to answer these questions. I put sniper on in hopes to be able to just turn key and start without fumbling with pedal to keep it going and to correct idle drop when ac kicks on. So I have been driving it for about 400 miles now to numerous car shows and going out for cruises around town, trying to work some of the bugs out from everything we did this winter, but I notice when I take off from a stop sign or I cruise at a very low speed (say30 mph) it seems to be very boggy from no throttle to about 1/8th throttle. These aren't generic newsletters either but instead personalized emails. I had that problem, right out of the box it would not power up, sent it back in, had defective hand held. I am extremely suspect of what you were told about the Sniper ECU monitoring fuel pressure, for several reasons. Going lower with the blanking might pay dividends, but there is so little room below 7/8 that you will quickly be in a range where every tiny variation in the TPS or MAP is throwing extra fuel into the engine. The throttle position should be zero. The solution is to either lower the IAC hold position or increase the RPM above idle to start ramp (default is 1000 RPM). But now that Terminator X is available, I highly recommend going that route. The engine makes very low vacuum at idle. We have never had that problem with any of the units that we have shipped. *Possible delays due to Covid-19 click for more information. When I am coming to a stop, the rpms will hang at 1200-1500 rpms. Bryan McTaggart 02/28/2023 news I have seen this become blocked with debris / dirt in the fuel system and cause a high fuel pressure condition . Took it for a lap around the block and came back. Your task will be to find that. Should it not do the opposite and do this on a cold start not warm. We're never going to fill up your email box with nonsense. I've been having problems with my sniper efi just shutting off. It has gotten a little better after I drove it for three hours today.I want to save the Kik because if I get this working good then I would like to add A C and use the kick for it.Motor is Mopar 360 with mild cam and automatic. Sorta similar to a carb having the idle mixture set incorrectly (rich) or the idle speed too low. Note that sometimes you can get into a back-and-forth situation. This page was generated at 12:25 AM. Since the shield was put on, not a single problem, not one. I had a customer recently with a high idle problem that he eventually traced to pad plug on one of the vacuum ports. ps. Holley will take a look and tell you you have RFI and wish you good luck in finding it. I chased that gremlin for about three weeks and was convinced I had a bad throttle cable. This increased idle speed is triggered by grounding the orange wire in the 10-pin I/O harness. Handheld shows plenty of fuel so I dought it's an issue there. I will turn it up some more.Is this something that the ECU will learn? Hi Chris. the issue If you go too low then it may stumble or even stall when coming off of throttle. Therefore The iac will always be at 10% now, correct? Okay, try my method. If your fuel pressure regulator has failed (and they often fail by blocking return fuel and maxing your fuel pressure) then it could lead to rich idle, particularly until your engine gets up to temp. Hello. I followed the instructions and set the IAC to 2-9% when warm with idle at 850 RPM. 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. I was looking at a data log from my truck earlier this week and noted that at idle my IAC was zero. installing and cruising down the highway 70 mph I just wonder if all I have to do I've changed all the Thanks for all your help Chris! There is a chance that the IAC is open but displaying 0% so start by putting your finger over the IAC opening. TPS 0. The warmer the motor, the higher the idle will be at this point. I ask because I'm using a PCV valve with my Sniper and have random idle issues as well. If the IAC number is increased during this high idle, review the points about high idle from tuning issues. )So before I hook up another gauge to see if the Auto Meter is bad (assuming I can find a 0-100 test gauge in my shop). Idle quality is great, RPM is good, sometimes IAC is jumping around from 35 to 60. The Fuel Base map is perfect, the car works well, runs well, running through the streets, the car is great. 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. The first 250-300 miles were amazing as the Sniper EFI worked flawlessly. That is a good thing.I don't have a specific target RPM but always encourage automatic transmission users to bias the idle just a tiny bit higher than what you might otherwise. 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. 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. Um, no. 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. A simple remove & clean will remedy this . issue. I have driven it a few times maybe 100 miles or so. I watched the butterflies start to open at about 35 on TPS. 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. I think you'll be all set! And the rather cavalier "Absolutely!" It's going to be really difficult to nail down the problem with the several simultaneous changes that you've made. Even 50 RPM can make a difference in how much impact the transition to Drive has on the idling engine's ability to stay at a fixed RPM.I would not recommend it in this situation but anytime a "kick" in idle speed is desired that is easily done by setting the kick value in Tuning > Advanced > Adv. You will need to change the -40 degree idle speed setting again but I recommend not touching anything else. when things aren't working and this provides just that. Fought a high idle issue until I changed your idle speed curve fix along with dropping the IAC hold to 10%. Is there away to lean the idle out? :-) Just don't let the parts go flying. Note that Brazilian gasoline has 27% ethyl alcohol. It meets the target idle perfectly in either but if I lightly stab the throttle it tries to stall after slightly revving. https://www.gmperformancemotor.com/parts/19210007.html, http://forums.holley.com/showthread.3128#post83128, If this is your first visit, be sure to One additional wrap on the secondary coiled shaft spring is all that's necessary. 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. The window you saw in the image above pops up. And so glad you guys are enjoying the Sniper EFI system. 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. It sounds to me like it is way retarded.In the event that the timing is right then take a look at your AFR--the actual AFR, not the target. I'm new to the efi thing and any help would be seriously appreciated. I'd say make sure you buy from someone who can give you good after-purchase help (hint!) Maybe give it a half-turn before you start it and then start and tweak. If this is the case then some adjustment of the linkage or the butterfly plates themselves is necessary. Next, reach down into the secondaries and push the butterflies closed. I have certainly seen this before on other fuel injected vehicles when hot. Chris thank you for the info. Put a strong piece of tape over the IAC breather hole--duct tape or something that couldn't possibly be sucked into the throttle body. Thanks for the info Chris. Honestly, I've never seen this happen but if the butterflies were misaligned on the shafts it could allow too much air to enter. Bolt on 4150 Flange Carburetor Replacement. One way is to very carefully watch the handheld monitor, and that may be adequate. mail today. Shutoff engine wait 30 seconds, turn key wait for display to come up, start engine. There is no sense proceeding until your TPS is at zero at key-on. any ideas? Car has run perfect every time and has never hesitated or stalled since. I'd suggest that you assume everything the previous owner did was wrong until you can prove that it was done correctly. 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. Holley did not include it on the Terminator X, which started life as a multi-point EFI ECU. You'll have to go back and forth a couple of times to get it just right. Incorrect connections will result in excessive resistance. The Sniper resets the TPS to 0% each time that you key the system on. I'm compltely stumped and my wife is certainly upset I'm spending so much time between the garage and the computer for something that should basically run out of the box. Hey Chris! Seems to be working. (If you do this you will need to reset the -40 degree setting mentioned at the top of this article. Does this seem reasonable and how hard will it be to get the idle and off-idle performance correct? We have shipped quite a few of these to customers in Australia and New Zealand so I know that there is becoming a good following there!We recommend this Inline 10-micron fuel filter to prevent problems like that. If I'm driving along and pull up to a light and leave it in gear it idles just fine but it seems not to be able to compensate if I put it in neutral and then back and drive. This curve turns the idle speed down as the engine warms. If you haven't installed a )Take a look at your AFR during the starting process. The link above includes the option to buy a -6 AN Nice to meet you. They also worked with me on a sale I missed and price matched those parts. 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. That is the default "Clear Flood" TPS setting and turns all fuel off until the engine cranks. % = 49 When the system is up and running the fuel pressure regulator inside the Sniper is making a rattling sound like a shaking a paint can. It could be that the air flow across the secondaries as they are opening is creating that whistle but that isn't commonly the case.Did you check for leaks around the gasket of the air cleaner? I am at the point where I almost insist that every Sniper EFI System owner purchase one of these. All EFI systems need a large fuel filter to trap dirt and yet not reduce volume. It could be a problem with the power/ground for the Sniper but much more commonly this is a result of too much RFI. Another suggestion is to add an extra turn to the spring built into the linkage to increase the closing force on the throttle shaft. you have it set. Do I need to try taping up the IAC port and setting the idle off the idle screw? Adding a wrap to the return spring on the shaft is one alternative to solving this. No timing control, coil negative ignition type. 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. All times are GMT-6. 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. If there's any run time on your current setup the Sniper may have some bad learn data due to what appears to be timing issues. Second, Holley just released over the weekend a video on how to implement a flex fuel sensor on their HP and Dominator ECU's. If no air is passing (and the idle doesn't drop) then your IAC is working. Sniper EFI Idle Tuning. MSD pro billet and 6AL box Simply go to those cells, tweak them up or down as required, and the ECU should now be able to learn its way around the bog. It started right up and we did your idle control fix and all is good at idle. Realize that when you drop the throttle, the engine enters a condition it will only see for a fraction of a second at a time. Sniper EFI offers superior throttle response and wide-open throttle power. is train the system or there is actually something wrong.I do love the system at The last pic is with the car in Drive. After only running for about 15 minutes or so the system starts to fail stalling the motor. I put it in neutral and the idle RPM had increased to 2100-2200. No air should be able to pass. If you haven't confirmed that they it is worth checking. So this is my issue ( I did just email Holly). Idle Tuning is a very important part of tuning any EFI system, especially our self-learning units like Sniper or Terminator X EFI. Rpm with 4-8 iac but it still shows red and shuts off randomly at idle and it won't even drive 2 miles without shutting off. Also what would you say a desired idle should be for a 3 speed automatic ford? idle at 1100 on the "stock" file it's better with street strip.The IAC counts will be at zero. Some have suggested the gasket might cause it but I've never heard of anyone fixing the whistle by adjusting the gasket (and many have tried. After a complete cool down it will do the same thing. Just getting it to act right at startup is a struggle. 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. Yes, having an accurate TPS is very important at idle. This is extremely unreliable afrer warm. If you have a bellcrank in your throttle linkage, ensure that the linkage is not engaging the bellcrank at an angle greater than 45 degrees at either end of the throw. Since a key cycle resets it to 0 and out to 30 or wherever Since the load is more of a wave that increases the most initially and then decreases again, the ECU is doing really well to get the idle under control in only two or three over/under shots as you describe.You don't mention if you have your Sniper ECU controlling timing. The latest was changing the power brake booster.Today I drove it to work and no issues at all. Just wondered if you've ever run across a system not powering up? (Grease can sometimes do the same thing as a more permanent gasket sealer without making the removal of the air cleaner such a pain.). This will let you know at a glance if something is going awry with the fuel pump. Your comment doesn't imply any sort of problem that would make me give up on idle timing control. check, I guess after reading everyone saying how great the system is after Watch videos on installation hints and if you haven't yet, download & read every Sniper installation guide you can find online. I also raised idle at Park a bit with the idle screw. I set it exactly like the instructions said and my iac is not only all over the place but when I finally did get it to the 2-10 range it's highlighted in red. It sounds a little different from mine, since it commands a 1300 or so increase intermittently. It appears that I could now use the dongle and a laptop to custom tune for idle issues if needed. Sorry for all the questions, new to the efi world. However, I have never found that to be the case. If you find that adding 5-10 degrees of advance helps then it's time to do reconfirm TDC. :-). If I rev the engine a couple times in neutral it will finally return to idle & usually will not do it again for the rest of my trip. It only comes back to normal if I turn the engine off and on again. If the engine idles at 750 RPM with the throttle plates all the way closed and the IAC at zero then there is some sort of an issue. Inj. Chris, Please let us know how this works out for you! Coming home from work today it was much warmer and took a little longer due to traffic. Cheers Darren. One of them might be faulty. Earl's Mechanical Fuel Pressure GaugeI could use that for a quick troubleshooting for 1/3rd the cost of the Holley one. The throttle plates are misaligned. If you datalog the Sniper ECU and see multiple overlapping traces for the same signal, you likely have RF-induced problems. If you can track specific engine coolant temperatures where the engine stumbles and dies that would be a good place to start. If the solutions suggested above are not working then you need to review my article on IAC Testing Procedures. 90% of time with engine hot. Or, at least, it should. Sniper setting is Stock camshaft. The hold position is part of the response that keeps the car from dying when you come off the throttle. I can adjust at 160deg, but my fans turn on at 180deg. Is this an issue to worry about? This will tell us if the ECU thinks that it is in control of setting the idle or if it thinks that you are driving the engine speed with the pedal. Price Point: $, Advanced throttle body injection systems capable of transmission control and more. By the way your site and your accessory products are nice. 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. Try it! I thought 12.0 was leaner at idle, but I figured out I was wrong.lol. That way you can get into that part of the table that needs tuning, and you can watch your learn numbers grow. Am I missing something. 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. 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. Setup: 1965 Impala SS; ZZ6 Crate Engine, EFI Distributor. Both Sniper and trans controller grounds were direct to the battery ground, as they should be. Be aware that there is a spring behind there and a diaphragm that you don't want to tear. Is there any chance that your timing has changed since you installed your Sniper? The jack-rabbit start can usually be minimized by adjusting the throttle linkage. Do I have to hook up sniper ac wire to relay or should iac pick up idle? Solution #1 Put car in gear take off and the engine runs GREAT, no issues drive for 10minutes take car out of gear and engine idles correctly IAC between 2 and 5 Solution #2 Shutoff engine wait 30 seconds, turn key wait for display to come up, start engine. That is likely just confusing the issue.Instead, choose whichever setup most resembles your camshaft and stick with that. Drop the IAC parked position a bit at each temperature point and sort of back into the solution. I think in some of the Wizards with the handheld it doesn't use 57.5 as the default. 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. What I would recommend is getting somewhere that you can spend a significant amount of time doing starts. Tried that and it didn't work? This minimizes installation time and packages really well on a diverse group of engine applications. Was perfect idle iac reading 3. If the screen shows iac at 0 and you block the hole to find it open what does that mean? But if you can datalog the bog you can know much more precisely what is happening. It does this with the engine off. I recently bought the car with the EFI system on it. If I put the truck in neutral the TPMS will raise all the way up over 2000. :-). Seems like its too slow to grab idle when ac kicks on. 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. Give that a go and see if you don't make some progress! 3 different fuel pumps. :-). Ok, so there are a couple peculiar things going on here. He has walked me through every question Iv. I have replaced the IAC motor and the problem remains. I'm going to jump out on a limb here and say you either don't have adequate fuel flow or pressure. What I can't explain is why your TPS is acting so randomly. Do please let us know what you find out! The engine ran so good, I would have never suspected the Fuel Pressure to be an The Sniper Quick-Start Manual provides the following instructions for setting the idle. But get that fuel system fixed before going any further. Hello, I am having a tps and idle issue. When I turn it off and try to restart it just cranks. The Street/Strip and race cam setups tend to be too rich initially. Good afternoon Chris, thanks for taking the time to help all of these folks that didn't purchase from you- myself included!The issue I seem to be having is at idle in both park/neutral and drive. 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. mean that the IAC is causing it. Once we recognize that, the next step is to narrow down all possible sources of additional air until we discover the cause.Start by keeping an eye on your IAC number. For the first couple of drives it was running well, Sniper EFI was working exactly as advertised. Well, it sounds to me like your Sniper is doing its best to reduce your idle. The headache is the Acceleration Enrichment. nothing stays steady. EFI Systems based on Holley's world-class Dominator and HP ECU's. Glad to hear that things are working well! I'll give the ". )Since this isn't a consistent issue with all Snipers that tells me that different IAC settings tend to make the whistle. What should I be looking at to calm this down? Tps is saying 26% when it at idle. Installed sniper on 65 galaxie.