Idles ok, runs great cruising, but from a stand still or downshifting and making a turn, when I get back into it, it wants to fall on its face. Cheers Darren. Its just at low speeds, not sure if its loading up or leaning out. What must remain foremost in your mind is that the only thing that can cause the idle to increase is additional air getting into the engine. Should I just disable idle timing control? I'm thinking it could be the fuel pressure--- since I have a new Spectra EFI tank and there's been some reports of the interior coating coming off and gumming up the pump however the sniper display DOES NOT show fuel pressure.the Sniper DOES measure fuel pressure on its own - i've confirmed that with holley techs as they told me to purchase the fuel pressure gauge that can just hook up to the 1 wire gauge harness from the Sniper. So you installed your Holley Sniper. I've been messing around for a bit trying to eliminate any possible vacuum leaks. I also raised idle at Park a bit with the idle screw. Strangely, what I've seen is that it idles too lean as the injectors are effectively shut off.Thanks again for the follow-up and glad to hear that everything is working well now. 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 have driven it a few times maybe 100 miles or so. Just getting it to act right at startup is a struggle. Target AFR at idle is 13.8%. !I called Holley today, and before I could even described the symptoms the Hello Chris. It is always best to get the base map as close as possible before adding acceleration enrichment. It's called tuning. Thank you chris for for getting back to me on this matter.I'm using russell hi pressure gas line to feed the gas up to the sniper and using the stock steel gas line that use to be the feed line for the carb to return the gas to the tank. Capability Range: Advanced I called support line he said he would have to look into it and call back. mail today. 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. Those don't impact the way the engine runs and can cause the whistle sound you describe. 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%. The first 250-300 miles were amazing as the Sniper EFI worked flawlessly. Even at 0% it's sucking a bunch of air through the IAC port. 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. Seems to be working. FYI: Car is a 1970 Mustang 302 Ford Racing roller motor. 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. I installed another return spring for the rear plates problem solved instantly. Well, it sounds to me like your Sniper is doing its best to reduce your idle. However, I did have another fellow who contacted me that claims he went through three units before he could get one that would talk between the ECU and the Monitor. Is that normal? I will try the other stuff when I get off work. I've made all the adjustments, all the settings, and the IAC issue is driving me crazy. 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%. It shuts off when coming to a stop sign, at any cruising speed and romdomly at idle in park but never when excelerating. I'll have to check again tomorrow. Sniper EFI offers superior throttle response and wide-open throttle power. Car was running great initially. Don't make any changes more than about 10% and keep the same basic shape as the original (High/flat below 20 degrees, sloped downward up to 180 degress, and then flat again above that.) to. But nothing beats a good solid gut-check When stopping, the brakes are unable to overcome the engine so I go to neutral just to stop fighting the engine. 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. But after sitting static idling for a little bit, the IAC goes to 100% & stays there. I' m going to put the 3rd new pump this coming friday. At this time, TPS is 0%, IAC is 50 to 60%. Let It started right up and we did your idle control fix and all is good at idle. I think that your timing is too retarded. Please advise. If the issue persists, you may need to replace the IAC. any ideas? :-). If not then you have some other issue that is behind this increased idle. Fuel Flow lb / h = 12.1 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). 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). I'm so glad you found this helpful--that makes my day!Don't get too concerned about the specific learn percentage. 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. Let me start with the engine not starting until you press the throttle. 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. I am new to the EFI scene but want to learn. You will find a startup IAC percentage, an amount of time it holds at that percentage, and an amount of time it takes to idle down to the normal idle speed.By default, that number is 50% at normal operating temperature. Edit I just ordered a Holley return / regulator and cap for the sniper ouletOh, this is not an OEM Master Kit, but the fuel pump should be the same EFI Pro shipped this kit. 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. A simple remove & clean will remedy this . I never had a problem with this. Also what would you say a desired idle should be for a 3 speed automatic ford? What can I do? It is temperature dependent but 30 is commonly where you find it. It may take a few tries. 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. Well, it turns out that with the current firmware this throws the IAC control into a bit of confusion. But I think it is safe to say that you are now at a point were some manual tuning is a good idea. Does that make sense to you? 90% of problems, (INCLUDING MYSELF) could be answered/fixed by just reading the instructions. This is actually more troubling than the sound you originally described. Ive tried setting the prime setting above 150 but it wont take, it always goes back to 150. No power at the programmer and no fuel pump running. check out the. nothing stays steady. TP range is normal goes up to about 90% with throttle pedal to the floor. Plus, you can email that file to me and I can be of more help. Copyright 2017 Cyberspace Automotive Performance, Inc. All Rights Reserved. And your understanding of how the throttle position affects idle is exactly correct. If i adjust the throttle plate screw in to bring IAC in to proper range say around 7 the engine is running around 2000 rpm. Once it decides to come back down, it does so with no issue. This is more of a bit of a reality check. Simply turn the idle speed screw on the linkage in until the throttle plates open enough for the idle to increase. All of the wiring exits below the rear fuel injector cover, for a completely stealth installation. The IAC is hanging open and not really at 0. Now I have most of the bugs worked out it runs fine on the highway and around town it's just the idle. It then started working normally again. Start with the most gradual throttle input you need to launch well, then slightly increase until you feel some stumble. the issue If :-). In some cases, you may only be able to put as little as 10 RPM between the hard idle and the target idle. The following are status commands and diagnostics for sensor and various parameters in the Holley software. I ask because I'm using a PCV valve with my Sniper and have random idle issues as well. 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! 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. Another suggestion is to add an extra turn to the spring built into the linkage to increase the closing force on the throttle shaft. We've already tried adjusting the Acceleration Enrichment chart in all ways, going up and down, RoC Blanking, everything, it has no effect. When I turn the key on I can hear it prime, but I don't think im getting enough fuel. 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. The car cruises fine, and if I was to keep idle at 2000rpm the issue wont happen, its only when the car tries to ramp down to idle position.Thank you for your help, any advice would be appreciated.Thank you,Eric, Whenever we see the AFR go to "Heating" that is an indication that the ECU has been reset. We have never had that problem with any of the units that we have shipped. If I were there in person I would test the function of the IAC (see this article.) 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. 3 different fuel pumps. This is Intermittent meaning, I can run this test 5 times and IAC will function incorrectly 2 out of the 5 times. Thanks for all your help Chris! 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? Then follow all of the instructions above, including confirming the idle speed curve setting at -40 degress as well as following my 10-step process for setting the idle. I have seen this become blocked with debris / dirt in the fuel system and cause a high fuel pressure condition . The IAC should display a 2-8% to bring the idle up to the actual target. This may require shortening or lengthening a rod. And your question is very perceptive: You must first know whether the bog is a lean or a rich condition before you can make the correct adjustments. when things aren't working and this provides just that. But after sitting static idling for a little bit, the IAC goes to 100% & stays there. It's hard to know what the previous owner did right versus wrong. What could be the cause? This happens no matter how much I adjust the idle screw. MSD pro billet and 6AL box Sniper EFI Tuning & Tech. I have installed my Sniper and the car runs great. Please let us know how this works out for you! Holley Sniper EFI Troubleshooting Mudford Garage 8.6K subscribers 38K views 3 years ago My Bronco with Holley Sniper EFI was running poorly. Pricing was reasonable, shipping was prompt and Chris helped me with a wiring question during my install. I did read some comments on regulator issues is there a way to check it for an issue ? Once engine is warmed up been driving for awhile. I think that your Sniper system is working fine but would definitely check ouf the fuel pump. The small rubber plug had a leak. The link above includes the option to buy a -6 AN 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. Now, in my lifetime of experience with Holley ECU's that seems unlikely, but this guy sounded really sharp and had nothing to gain by convincing me of his dilemma. The Sniper EFI system looks at the closed-loop fuel compensation required to reach your target AFR. It will still change a bit with weather changes and when you get into infrequently-used sections of the map, but it's nothing to worry about.Regarding your idle speed immediately after start-up, that is determined by your Idle Parked Position. applies here because it is so important to realize that just because the IAC Your task will be to find that. 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. Don't know if I should put this in a separate post. Also its extremely rich at idle. When you set the Static Timing to 15, what did you read with the timing light? It is easily solved by installing a four-hole gasket or four-hole spacer (depending on your hood clearance issues.) Turning off and then on again, the engine returns to normal. https://www.gmperformancemotor.com/parts/19210007.html, http://forums.holley.com/showthread.3128#post83128, If this is your first visit, be sure to
There are six different acceleration enrichment tables that you can tweak and that may be the way to go. Holley will take a look and tell you you have RFI and wish you good luck in finding it. I installed a sniper efi system on my 1969 Camaro. EFI parts, including the throttle body, and the problem persists.Please give me a hand. A common issue we see is a result of poor fuel pump grounding running a eyelet from the pump ground to a rusty or painted surface. Capability Range: Professional It is reliant on the data acquired by the included wideband oxygen sensor. Glad to hear that things are working well! Target AFR, A / F = 13.5 When I covered the IAC with my finger, the RPM dropped so low it stalled. idle at 1100 on the "stock" file it's better with street strip.The IAC counts will be at zero. An under-sized filter will allow part- throttle operation but fuel pressure will drop at WOT and run very lean - perhaps surge under power. 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. When this occurs, I sometimes can shut it down and it will return to the correct settiings. Eventually the IAC will drop back to zero, I'll readjust it to 850 RPM & 2-9%, and then watch it steadily climb again. Last night I tried setting the IAC and had the same problems after it's warmed up. If your fuel pressure is at or about 60 PSI then visually inspect the barrels of the throttle body while having someone key on the Sniper. 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. Price Point: $$$. I will let you know what the results are. There are two ways to address this--you can let the system learn or you can manually adjust the acceleration enrichment. I think you will find that it will learn its way through this. That's a nice change of pace--a low idle issue! But as you see from the recent revision I did above you seem to be having a fixable issue. If your TPS is at zero and your IAC is at some random number above 8% (but not exactly 30%) then for some reason your engine has not met the conditions to ramp down to target idle. I have a Holley Sniper for almost 11 month now and it was running fine with no problems until now. The fuel pressure regulator in the Sniper is fairly simple and not prone to failure, as far as I know. New install, when in setup wizard TPS says 90 percent and I checked the linkage and butterflies. There are a few tell-tale signs that can help you diagnose the problem. The only way to do this is by installing a mechanical fuel pressure gauge. 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. When you have the issue you should disconnect all hoses and plug the ports on the Sniper. Confirm the placement of all wiring, ensure that the WBO2 sensor is positioned properly, etc. But after sitting static idling for a little bit, the IAC goes to 100% & stays there. Hey Chris What would cause the idle to faulter like that? P.S. 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 idle is 1350-1400 with the idle screw at initial contact. 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 that sometimes you can get into a back-and-forth situation. This curve runs fom -40 degrees to 260 degrees, and gradually reduces the RPM along that range. If you drop it too far the engine will stumble or stall when coming off the throttle with the car out of gear, so you'll know when you've gone too far. These aren't generic newsletters either but instead personalized emails. 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 there are several degrees of play there in which it should still work fine. When I see that your TPS is 1%, that tells me that you may have an RFI problem. Advanced throttle body injection systems capable of transmission control and more. 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. You'll have to go back and forth a couple of times to get it just right. Though it started and ran good, it was dumping fuel and would not lean out to AFR set points. If you do find you have RFI issues then I've written an . If you can send a data log to the vendor from who you bought your Sniper EFI System they should be willing and able to take a look and recognize RFI and then give you some ideas on solving it. Ilike a few othersam having idle issues. 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. :-). It then idles up from 750 to 1100. Duty Cycle% = 3 My IAC was constantly at 100% at idle. Idle was around 1000 mark and iac 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. Hi Chris thanks in advance for any tips. As I said above, you could have a bad IAC, but then again, the IAC might be fine and there's a deeper problem such as RFI noise causing the issue or a vacuum leak that is confusing things. I've been having problems with my sniper efi just shutting off. I am having an idle issue (other than that is absolutely perfect). When you first posted this I had no idea how to respond. Im in Australia, so stuck the sniper on a 355 Holden engine with CD box. Holley documentation and videos didn't work and the $300 I paid for "expert" tuning didn't work either. Thank you in advance for your help and providing us rookies with your 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. In this short video you learn to replace the IAC. That initial rev is going to be determined by your IAC Park Position. My problem with the sniper is the whistling and hard throttle pedal, I have a 700r tranny with a kick down cable. 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. 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
Then do it just a bit faster--just enough for it to bog a bit. Okay, try my method. I went on the good ole interweb and found your website which was VERY helpful! But another thing to consider is adjusting your target A/F ratio. 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. TPS 0. Ok, so I'm stumped! The 5-6 times it has happened now have been after the car has been running for at least 20 minutes. Now that you've installed at least four Snipers it is going to be imperative that you learn to create and read datalogs. Thank you. I certainly appreciate your frustration (as well as your wife's!) Drives just fine but won't stay running unless I keep my foot on the gas. To keep it running in gear, I have to bump the neutral idle up just over 1000 RPM. The hold position is part of the response that keeps the car from dying when you come off the throttle. Do you have a PCV on the engine? If the solutions suggested above are not working then you need to review my article on IAC Testing Procedures. I have driven car about 200 miles. To be honest, you sound like an ideal candidate for Sniper ECU ignition timing control. If no air is passing (and the idle doesn't drop) then your IAC is working. Make sure that your blanking level is _below_ that (being careful not to find yourself in the situation I describe above.) Just wondered if you've ever run across a system not powering up? There's a procedure there I can share with you if you'd like.. When you open your IAC to 30% you are naturally going to have a high idle condition. Idle quality is great, RPM is good, sometimes IAC is now between 2 and 5 exactly where it should be. 63 bomb I got it home, checked it all over, everything is hooked up correctly. In most cases the IAC (Idle Air Control) circuit is the source of the whistle. 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. :-) Just don't let the parts go flying. I also noted that after some time, I could change those values as I saw fit. Camshaft is M-6250-B303 .480 lift intake & exhaust, duration at .050 is 224 degrees for intake & exhaust. It turns out that some of the Snipers are shipping with the minus 40-degree setting drastically lower, as shown in the following image. These problems will go away when you do that. 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. Also if I give it a There is a chance that the IAC is open but displaying 0% so start by putting your finger over the IAC opening. Ok, so there are a couple peculiar things going on here. Enjoy! Or is there something else I should holley efi. If I keep the rpm's up it does fine but my clutch can't keep up with this for long.Also when I cover the IAC port the engine dies. I guess we can't have everything. Two things to keep in mind as you do that. But you've got to find where air is getting into your engine.The reason it's going up as high as 2400 RPM is because once you press the throttle beyond 1% the IAC opens to the park position. I appreciate everything you are saying. Is this an issue to worry about? Sometimes an engine can produce enough vacuum to pull the secondaries open slightly. I set the AFR at 13.5 and all is good now. Next, clean the IAC and all related parts with brake cleaner. It only lowers to 2-6% when I take my foot off the gas. I readjusted my IAC, now it's perfect. So, if pressing the throttle is making it start, it's because you're flooded.Which is consistent with your rich idle condition comment, right? This increased idle speed is triggered by grounding the orange wire in the 10-pin I/O harness. I have probably 200 - 300 miles on this engine and it has always done this. Capability Range: Moderate Note: The IAC breather hole is the roughly 1/4-inch triangular hole that sits above and between the secondaries. ps. Otherwise, if removing the air cleaner eliminates the whistle then try to use a thicker gasket or try lightly greasing the gasket. https://www.youtube.com/watch?v=2JpHlS1ymBc, If this is your first visit, be sure to
Doesn't want to start, runs like crap. My issue is that the TP% will not reset with key cycle and its idleing at 9% TP. 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). itself out and hold idleeventually stalling. And, while that is happening, make a note of the temperature before you engage the starter, and then the rpm when it starts.The Idle Parked Position is set on a temperature-based graph like the Idle Speed Curve. My Sniper started having a ticking noise-- I have 90 miles on my Sniper, but this started the last 10 miles or so: it still drives fine, but it worries me so i've stopped driving it for now. I presume your idle speed table doesn't increase at 200 degrees? It runs perfectly fine other wise. I will turn it up some. To get it to idle the tps is at 2-3-4% even with linkage disconnected and a return spring installed. 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%.