holley sniper efi iac problems

(Plus they it just looks way cool in your engine compartment!) 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. Once engine is warmed up been driving for awhile. 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. It's the same one that Holley puts in their Sniper Master Kits and I've never heard anyone with anything but good things to say about it. The only way to confirm RFI problems is by doing a data log. Use the idle speed screw to set the idle at a comfortable warm-up speed. Try it! You'll have to go back and forth a couple of times to get it just right. 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. Tps is saying 26% when it at idle. Turned it off and on again. no timing control. Intake has been on and off 3 times no change. Hello, I am having a tps and idle issue. Don't be surprised if one or the other is slightly open. When I drive with warm engine the IAC is at 30% when pushing gas, but shouldn't it be at 0%? The Street/Strip and race cam setups tend to be too rich initially. When I see that your TPS is 1%, that tells me that you may have an RFI problem. :-). But, whether your vendor provides you with tech support or sends you to Holley, I'd start by getting them a data log and asking for some insight. This may require shortening or lengthening a rod. Hi Chris I didn't get any traction on Holley.com Key, I believe, in this success is solid connections, resistance-free signal and ground paths, and solid RFI rejection. Holley Sniper IAC Problem 04-26-2018, 11:30 AM Hello. Intermittent stalling usually points to radio frequency or electro-magnetic intereference (RFI/EMI). 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. Fortunately, I have an article that goes into this in some detail. The engine ran so good, I would have never suspected the Fuel Pressure to be an Duty Cycle% = 3 Yes, it will talk to you--but not with words. This curve runs fom -40 degrees to 260 degrees, and gradually reduces the RPM along that range. If it does then you can put on a heavier spring so the advance doesn't come in as fast, or use a lighter weight. This will go a long way to improving your fuel map without manually adjusting the acceleration enrichment. I would only play with this if you are finding that the other adjustments I suggested aren't working. Resistance results in heat and heat results in more resistance. Fortunately, Holley has another product that can solve that: Hydramat.. Hydramat is not inexpensive but you won't believe what it can do. Copyright 2022 Holley Performance Products, Inc. All right reserved. Your AFR is pegged lean. If you hit the gas it pops & backfires through the throttle body. This curve turns the idle speed down as the engine warms. If you find that adding 5-10 degrees of advance helps then it's time to do reconfirm TDC. 63 bomb You advise would be greatly appreciated. Also ensure the TPS Position returns to zero at idle, & the IAC Hold Position isn't setup too high. Installed sniper on 65 galaxie. If I put the truck in park it comes down to idle. Camshaft is M-6250-B303 .480 lift intake & exhaust, duration at .050 is 224 degrees for intake & exhaust. Price Point: $$$. I took some pics of the sensors page this morning after the car warmed up. The noise is definitely coming OUT of the throttle body. Since that has long been corrected we have moved that information to the bottom of the article.). He is able to get it to start by quickly depressing the accelerator to at least 60% and releasing. TPS% = 1 Any idea's? The Sniper even has a feature that allows it to use the idle timing to control the idle speed. Copyright 2022 Holley Performance Products, Inc. All right reserved. IAC Testing Procedure for EFI Systems Next, clean the IAC and all related parts with brake cleaner. 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%. Copyright 2022 Holley Performance Products, Inc. All right reserved. I would recommend that you call first thing in the morning, as they tend to get quite busy during the day and wait times can get long. technical rep said "You ahve high fuel pressure". On startup- cold or hot, I get a 2 second high idle of about 1500 RPM before normal set idle of 750 RPM happens. 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. 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. It is a common one. Nice to meet you. This is more of a bit of a reality check. is jumping all over the place when you experience this condition, it does not So try changing your IAC hold value slightly:Tuning : Advanced : Adv. Took it for a lap around the block and came back. He thought that something was wrong because when he set the idle 50 RPM below his target the resulting IAC postion was far too big. Cracked casing from a side cover screw being installed crossed threaded. I can adjust at 160deg, but my fans turn on at 180deg. So you installed your Holley Sniper. Laptop Access Definitely would have went with you guys. )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). Doesn't want to start, runs like crap. I installed a Holley Sniper on my Ford Maverick 302 V8. 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. About two minutes after I get it set at 850 & 5%, it has progressed to 100%. You can disable the idle spark control at the locations below. The broad consensus has been that the Sniper is an amazingly straight-forward install and starts and tunes as expected. Sniper EFI Problems - Holley Performance Products Forums The Sniper EFI remote IAC (Idle Air Control) and plug is designed to gain installation clearance on some Sniper EFI 2x4 installations. To figure this out it's going to be important to gather a bit more data. The last pic is with the car in Drive. These are "transitional" cells, and you really have to make the effort to learn in these areas of the map. Idle was around 1000 mark and iac 0. It is temperature dependent but 30 is commonly where you find it. Hello Chris. What should I be looking at to calm this down? We can not hit it at all, we hit the pedal abruptly, the engine gives a lot of excess fuel, the AFR gets super poor at first, the car stops, then the AFR gets super rich and the car runs until it cleans up. I've helped folks work through a number of challenges with their Sniper EFI System installations. Turning off and then on again, the engine returns to normal. Just add 5 or 10 degrees of advance and see if it doesn't idle better. Sorta similar to a carb having the idle mixture set incorrectly (rich) or the idle speed too low. Unfortunately I did not buy my sniper efi from you. I thought 12.0 was leaner at idle, but I figured out I was wrong.lol. I have probably 200 - 300 miles on this engine and it has always done this. If so remove it. I keep doing that with the same result. So check that timing and I think that you're going to find you need a good bit of advance. First, recognize that the IAC and the TPS are not inter-related in any way. To start viewing messages, select the forum that you want to visit from the selection below. I've not heard of any others with this exact issue so I don't think it is a common problem. 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. Does anyone have photos of this additional return spring they installed? For the first couple of drives it was running well, Sniper EFI was working exactly as advertised. I have a Holley Sniper for almost 11 month now and it was running fine with no problems until now. I would suggest you take a look at that if you haven't already. Reducing that a bit will help. The data that you provide shows that you have at least two problems. Closed Loop Compensation rises to 100%, Do I just keep pushing it the same way to I've increased the IAC rampdown time to 8 seconds to try to combat this, but wondering if it will correct itself over time or if I need to possibly replace this TP sensor. It only comes back to normal if I turn the engine off and on again. Could the IAC be broken/malfunctioning? Start by doing the fastest start you can that doesn't bog. 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. If that happens then follow my 10-step process shown above. :-). If you complete the process and find that the IAC is less than 2% at idle, repeat the process and use the set screw to make the RPM about 60 RPM below the target. To do this, open up the Initial Startup gauge screen that was used in section 17.0. Coming home from work today it was much warmer and took a little longer due to traffic. 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. We will definitely be sticking with Holley from here on out for future retro-fits. 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. Any suggestions? After only running for about 15 minutes or so the system starts to fail stalling the motor. 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. After a stall the car will restart but will be in a high idle. I have driven a stand-alone transmission controller for the 4L60E in my (then) Sniper-equipped '95 GMC pickup using the Sniper TPS with complete success. )Take a look at your AFR during the starting process. There's nothing wrong with manual tuning, but at this point that is just compensating for an inadequate fuel map. I have turned ignition off turned screw in 2 turns and turned ignition back on and tps is at 1-2% not sure whats going on. At this time, TPS is 0%, IAC is 50 to 60%. 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. I did buy the Sniper from you guys and the service was fantastic. Somehow air is entering the engine that was not entering the engine when you originally set the idle speed screw. If you did not rotate the distributor to set the actual timing to 15 that might be the only issue. Ran 2 Holley carbs and an Edelbrock. Capability Range: Advanced I hope everyone enjoys this v. EFI Troubleshooting EFIand and EFI Tuning Tips - In The Garage Media I managed to get the IAC down to around 0% - 8%is this good? 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. 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. And the only way to be positive about that is with a gauge.Unfortunately, the Sniper does not provide an input for an electronic sender so the next best thing is an analog gauge. But, if the idle is so high that it is making you crazy then you might try dropping that number just a bit. But once you come off the throttle there is a minimum RPM that the ECU wants to see before it releases the IAC from the park position and that is normally 1000 RPM over the target idle. That is what I really respect about Holley. 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. However, I have what I will call a whistle at a throttle position on 35 - 50. As soon as I got the new one installed and wiredit fired right up and did everything it was suppose to do with no issues. In addition to avoiding this particular problem, the total solution is much better. You have to remove all hoses in order to debug the problem. Some suggestions: i did have the same problem.try lengthening the lever of the throttle.meaning the length from the center of the throttle to the point where you attach your cable or your rod from the peddle. This is actually more troubling than the sound you originally described. Thanks in advance for any advice. Find a lower price anywhere and we'll beat it by 5%! % = 49 At 0% it shouldn't be sucking any air through that port, correct? Am I missing something. 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. But after sitting static idling for a little bit, the IAC goes to 100% & stays there. Duration @.050 is 240 intake 246 exhaust with .574/.578 lift. If the IAC number is increased during this high idle, review the points about high idle from tuning issues. You mentioned going from 13.5 to 14.2 but you'd want to go in the other direction--maybe to 13.2.