holley sniper efi iac problems

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. 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. Wish I knew about it before I made my purchase. He said they have been having an issue with these lately. After the start process, If the idle speed is higher than the target idle then the IAC should begin closing as long as the TPS is below 2%. When you open your IAC to 30% you are naturally going to have a high idle condition. it will jerk and rpm will go up and down and AFR will be around 20 : 1 or more or less. I would continue checking the electrical connections along the fuel supply. A simple remove & clean will remedy this . Throttle Tip-In tuning can be a bit of a challenge but I'm confident you can get this resolved, Mike.Let me start by saying that unless you've really done a lot of driving on the system in some useful learning situations then I would set this issue aside and not even think about it. Also its extremely rich at idle. installing and cruising down the highway 70 mph I just wonder if all I have to do 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. That is what I really respect about Holley. Thanks for all your help Chris! I, too, wish you'd bought your Sniper from us! I had that problem, right out of the box it would not power up, sent it back in, had defective hand held. If not then I think you are going to find that this will solve much of your problem. IAC Testing Procedure for EFI Systems Advanced throttle body injection systems capable of transmission control and more. It is always best to get the base map as close as possible before adding acceleration enrichment. That changes almost instantly as the engine revs.Since the learning algorithm requires some time exposure to a certain condition to make larger changes, that half-second makes only the smallest impact. With an assistant pressing the accelerator, you need to make sure that when the accelerator is pressed to WOT that the throttle blades are fully opened, and when accelerator is lifted the linkage is fully at rest against the idle speed screw. The IAC going to 30 is normal. Relatively new Sniper EFI install on a '69 Mustang 302. 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! It's called tuning. If I read it correctly, the solution from the other thread seemed to fix a constant 300 or so RPM increase. They also recommended that their ground be spliced into the Sniper ground as close to the Sniper as possible. He is able to get it to start by quickly depressing the accelerator to at least 60% and releasing. Supports up to 650hp with Four 100 Lb/Hr Injectors! 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. 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. That is likely just confusing the issue.Instead, choose whichever setup most resembles your camshaft and stick with that. P.S. Now that you've got your IAC set I'm going to recommend that you run your setup wizard again, which will reset the ECU to the default settings. Thank you so much for your follow-up. *Possible delays due to Covid-19 click for more information. If no air is passing (and the idle doesn't drop) then your IAC is working. However I do have a couple of issues I hope you can help me resolve. Fortunately, I have an article that goes into this in some detail. It didnt do this with the carb on it. 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 your mixture is too rich, it means there's too much fuel and not enough air. Always had to set idle above 950. Thanks for the info Chris. Wish I had bought my sniper from you, but unfortunately didnt. 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 thought 12.0 was leaner at idle, but I figured out I was wrong.lol. But as you see from the recent revision I did above you seem to be having a fixable issue. Can the return line be an issue?So far this sounds like an ideal setup.>I have had 2 faulty gpa-4 255 walbro pumps go bad. If 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 believe because the TPS is not registering. Does this seem reasonable and how hard will it be to get the idle and off-idle performance correct? Start with the most gradual throttle input you need to launch well, then slightly increase until you feel some stumble. 63 bomb The distributor was loose. 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. If you did not rotate the distributor to set the actual timing to 15 that might be the only issue. mail today. 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. This happens no matter how much I adjust the idle screw. I chased that gremlin for about three weeks and was convinced I had a bad throttle cable. Doesn't want to start, runs like crap. Please let us know how this works out for you! Is there any chance that your timing has changed since you installed your Sniper? What should I be looking at to calm this down? The headache is the Acceleration Enrichment. I tried adjusting my IAC up to 10deg in both directions with no change. The idle will not return to the set value.The second issue is the same as the first but the motor will stall out. )Take a look at your AFR during the starting process. I am having an issue with the IAC on the Sniper. Any idea's? Ultimately, it is about making the pedal softer, particularly at initial throttle opening. The fuel pump is mounted under rocker panel as low as possible and far away from any heat. The team at Holley has designed the perfect solution for your problems. Please give this a try and let us know how it works! Well you were right air was entering from another source. What I would recommend is getting somewhere that you can spend a significant amount of time doing starts. Hello, Chris, thanks for the help.I have not installed the software yet, and I'm having trouble with two cars. But after sitting static idling for a little bit, the IAC goes to 100% & stays there. I go into much more detail about that in this article on startup tuning. I got it home, checked it all over, everything is hooked up correctly. My Sniper is 99% great! Your mechanical advance will naturally change the timing a bit but it should be fairly close. Technically it is a warranty-voiding maneuver so proceed at your own risk. knowledge with the sniper efi setup. I have it set at 650 and it idles anywhere from 590 to 700. I went on the good ole interweb and found your website which was VERY helpful! Hello. Have you confirmed your fuel pressure at idle is 60 PSI? And Earl's makes a fantastic little 100 PSI gauge. I will try the other stuff when I get off work. 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. 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. The engine has 14: 1 compression ratio, we can not use gasoline. If that tested out okay then I can really guess that there might be some sort of intermittent, temporary RFI. If you do find you have RFI issues then I've written an article on solving RFI problems. About two minutes after I get it set at 850 & 5%, it has progressed to 100%. I have one customer who is having some similar issues and his AFR is down at 9.6:1 when it won't start. All times are GMT-6. Then, when you experience the high idle, note if the IAC number has increased. 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. Seems to behave more better now. It's all part of the adventure! Don't try to correct for the fuel. The "PC Text" indicates what will be shown on the PC/Laptop data monitor or data logger. Does that make sense to you? If I adjust idle screw out to get the tps to zero or even 1% the engine will not idle. 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 Holley Sniper high RPM - IAC problem? Capability Range: Professional Genuine Walbro fuel pumps are virtually bullet-proof. Shut off car/restart and it's back to idle at Properly configured, the Sniper does a fantastic job of responding to the transition from Park to Drive. This page was generated at 12:26 AM. If you patiently adjust this over the course of days you will get it just right.Again, glad this is working for you and look forward to a good report in the future! 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. 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. The AFR was pretty consistent around 13. That way you can get into that part of the table that needs tuning, and you can watch your learn numbers grow. However, it is a good question so I thought I'd throw a few bits of info out there that I think might help.First, I believe that you may have a basic misunderstanding of what is being referred to sort of generically as AFR. If I cruise down the road at lets say 60 mph and lay into it, she will take off and go. Free ground shipping regardless of order size! If you have any questions about the car/setup let me know. The symptoms I had was a low cold start idle and going lean coming to a stop. When I cover it with my hands, it gets quieter. first attempt but as it tries to idle down to the target RPMsit can never even (It should be at or near 60 PSI at idle. I also noted that after some time, I could change those values as I saw fit. The Street/Strip and race cam setups tend to be too rich initially. Though they both are indications of the amount of opening through the throttle body, the TPS is the throttle opening percentage and the IAC number tells us how far the IAC stepper motor is opening the bypass air circuit.If I understand you correctly you are saying that the TPS reads somewhat normally (traveling from 9% to 100% or so) but that when you cycle the key it once again starts at 9%. I called support line he said he would have to look into it and call back. Now I have most of the bugs worked out it runs fine on the highway and around town it's just the idle. I'm Having trouble with the Sniper on high Idle. A problem since day 1 - YouTube Leave a comment if you've had this issue and how you resolved. It does this with the engine off. The Tech Tips and discussions are also great! I have a Holley Sniper for almost 11 month now and it was running fine with no problems until now. View Holley Sniper EFI Self-Tuning Kit - Shiny Finish. 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. Lubricate the linkage so there isn't as much native resistance. Target AFR, A / F = 13.5 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. Even at 0% it's sucking a bunch of air through the IAC port. I installed a Holley Sniper on my Ford Maverick 302 V8. What is it supppse to be at idle and while driving under heavy acceleration? Featured Products EFI - Fuel Injection $2.59 - $6,499.95 2179 Products View Parts Sensors 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. The ticking is inline with the fuel pressure I feel squeezing both the fuel return & delivery lines (like a heartbeat). I never had a problem with this. Get that thing installed and you're going to know a whole lot more about what's going on. :-DStill, I hate to leave someone hanging so I'll try to help. Except at idle. Yes, it will talk to you--but not with words. The answer will divide the possible sources of additional air into two, greatly simplifying the problem.If the IAC number has not increased, then review the article above regarding high idle from a vacuum leak or high idle from sticking linkage. All in all, considering the system has been installed for less than 2 hours drive time we're BLOWN AWAY at how quickly it is "learning" this engine. the issue Even though the Sniper's fuel map is programmed to provide the correct amount of fuel via injectors spraying at 60 PSI, if the pressure is jacked up to 90 PSI the wideband sees that you are rich and faster than you can even detect it audibly lowers the duty cycle to inject the correct amount of fuel. Holley documentation and videos didn't work and the $300 I paid for "expert" tuning didn't work either. Definitely not 90. Watch videos on installation hints and if you haven't yet, download & read every Sniper installation guide you can find online. When you experience this, before you touch anything or shut the engine down, first look at your TPS and your IAC. OK, I did the baseline idle speed screw setting. (Don't drive and watch--get a helper!) 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. The problem was RF interferance . 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 did change the -40 thing also. Changing the rpm curve and target rpm has no effect. 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). If that happens then follow my 10-step process shown above. Sniper EFI Idle Tuning - Holley Motor Life Also, I was seriously rich at idleso rich it hurt your eyes. The small rubber plug had a leak. You've got it running and warmed up but now you need to set. If more info is needed just ask. It is easily solved by installing a four-hole gasket or four-hole spacer (depending on your hood clearance issues.) Once engine is warmed up been driving for awhile. Hey Tommy, we've got at least one thing in common. IAC Creeps To 100% - Holley Performance Products Forums Hi Chris thanks in advance for any tips. Suddenly, the engine accelerates alone, hears a great deal of air being sucked in, 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. Often, folks will say, "I did everything you said. I'd really appreciate some help. I have adjusted many settings and eventually mess it up and go back to the original map. You just need to go back through the IAC adjustment procedure now that idle timing control is enabled. To figure this out it's going to be important to gather a bit more data. Make sure that your blanking level is _below_ that (being careful not to find yourself in the situation I describe above.) Great work, expert! Also when ac kicks on it will idle down and stall. 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. The throttle blade adjustment is at 2-6% at hot idle, and with warm engine 185F. 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. Remove the tape from the IAC breather hole and restart the engine. I have changed my roc/tps to 7 from 15 but that only took me out of learn mode. Have a look--I think this is going to allow you to fix your idle problem. Can the return line be an issue?I have had 2 faulty gpa-4 255 walbro pumps go bad. The problem I'm having is I cant get the IAC to drop down off 100%. I have quadruple checked my wiring and am certain it's correct. 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. The only way to confirm RFI problems is by doing a data log. That is the first thing you must find. Bolt-on carburetor style EFI for your classic car or truck. and if you do run into any problems then, yes, the plethora of tunability adjustments available through either the handheld or the Sniper Software will certainly be enough to get you right where you need to be! Ive played with the timing on this thing multiple times.Car was fullly restored last year. Note that Brazilian gasoline has 27% ethyl alcohol. Bolt on 4150 Flange Carburetor Replacement. We've already tried adjusting the Acceleration Enrichment chart in all ways, going up and down, RoC Blanking, everything, it has no effect. I have now determined with the TPS the noise correlates with the opening of the secondary butterflies. The 5-6 times it has happened now have been after the car has been running for at least 20 minutes. Um, no. Explained: Holley EFI Sensors and What They Do I would only play with this if you are finding that the other adjustments I suggested aren't working. PDF Sensor Diagnostics and Statuses - Holley Short drives is fine then it'll I recommend you have a look:https://www.efisystempro.com/efi-pro-hangout/holley-sniper-efi-instruction/solving-sniper-rfi-problems, I recently purchased your fixed linkage to open primaries first and the throttle linkage extender to also get a smoother pedal. The solution is to either lower the IAC hold position or increase the RPM above idle to start ramp (default is 1000 RPM). Save Share. That is not something I'd ignore. My issue is that the TP% will not reset with key cycle and its idleing at 9% TP. Is there away to program the ecu to compensate for this at start up. Im thinking a faulty TPS. Resistance results in heat and heat results in more resistance. You can find those settings here: Handheld: Tuning > Advanced > Advanced Idle > Rampdown, Software: Idle > IAC Settings > IAC Ramp Down. check out the. Take a drive and stop somewhere for 30 minutes, CTS is 170 when engine was shutoff. Hope this helps! We will definitely be sticking with Holley from here on out for future retro-fits. Perfectif you have the original synchronous linkage. I followed the instructions and set the IAC to 2-9% when warm with idle at 850 RPM. I did all of this before seeing the link you sent. But before you adjust the ECU to lean the idle out, first confirm that your fuel pressure is right. Jun 12, 2021. )If you rule out a fuel supply issue then we're going to have to gather a few more clues. But get that fuel system fixed before going any further. You have to remove all hoses in order to debug the problem. I'd say make sure you buy from someone who can give you good after-purchase help (hint!) Drives just fine but won't stay running unless I keep my foot on the gas. Part# 538-13. This curve runs fom -40 degrees to 260 degrees, and gradually reduces the RPM along that range. Sorry I didn't buy from you but I didn't know you had sold them. 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. 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. TP range is normal goes up to about 90% with throttle pedal to the floor. Sorry for all the questions, new to the efi world. I've been messing around for a bit trying to eliminate any possible vacuum leaks. is the fuel pressure. Hey Chris Holley will take a look and tell you you have RFI and wish you good luck in finding it. 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. Otherwise, if removing the air cleaner eliminates the whistle then try to use a thicker gasket or try lightly greasing the gasket. Idle : IAC Rampdown : IAC hold positionChange this by maybe 2% in either direction. There's nothing wrong with manual tuning, but at this point that is just compensating for an inadequate fuel map. The fuel pressure regulator in the Sniper is fairly simple and not prone to failure, as far as I know. 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. 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. Unless you have ignition control enabled, that is the only thing it can do to reduce the idle.Realize the only things that can cause the car to idle up as you describe are air and ignition advance. Also if I give it a If I were there in person I would test the function of the IAC (see this article.) Camshaft is M-6250-B303 .480 lift intake & exhaust, duration at .050 is 224 degrees for intake & exhaust. The Sniper EFI remote IAC (Idle Air Control) and plug is designed to gain installation clearance on some Sniper EFI 2x4 installations. Eventually the IAC will drop back to zero, I'll readjust it to 850 RPM & 2-9%, and then watch it steadily climb again. 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. 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.