If not then stop and buy one now. Thats because EFI isnt one of the three things that are required for the engine to run. Probably 3-4 seconds, and rich after it does fire. No, it did not help. Clicking, ticking and sucking sounds. Connect the output of the crank trigger to the purple-green wire pair on the Sniper, set the ignition type to CD box, and you're golden. Ill check the coil and see if anything else is attached. There should be no relay added to this wire. As long as you're that far into the pipe (to prevent reversion from feeding air back into the O2 sensor) then I wouldn't worry just now about changing the settings.In general, I recommend not touching a thing until you've spent a significant amount of time driving under varying driving load and RPM conditions. Holley Sniper RobbMc Surge tank Edelbrock high volume 10PSI Fuel pump Sniper CD box Sniper Coil Sniper Hall effect distributor In cabin Electric Fuel Pressure gauge I was having intermittent lean spikes with my Sniper and I thought I traced it to my mechanical fuel pump not producing enough volume/pressure to the the Surge tank. Try cranking immediately upon key-on--before it has a chance to prime. Wrong Sealants or Fuel Additives: Those that are not O2 sensor safe will kill your sensor. A low air to fuel ratio means the mixture is rich. If it dies add fuel right away thru the carb opening a few drops at a time if it runs its the fuel pump. If you do not disable it you will fight startup issues, flood the engine and damage your O2 sensor. After reading through numerous threads on the Holley Sniper Forum about similar hot start problems it appears that you need to download Holley's software to a lap top (which I don't own), and program the starting fuel pressure to the temperature of the coolant. The engine starts and idles great. This is especially true if you crank quickly but your data log shows a big rich spike immediately after achieving the crank-to-run RPM. In fact, MOST of the points on the fuse block don't do that! 02/23/2023. I have two questions at this time: 1. FE 390 that currently has a Pertronix distributor with the Ignitor 2 module. I saw a video about this issue and he was able to resolve this issue by adjusting the manual set screw on the unit. idles good, runs amazing. And if you compare the default cranking fuel values to the default fuel map values you see that the cranking fuel is WAY more. If you hook a fuel pump up to the fixed-pressure 60 PSI regulator in the Sniper and it can only get the pressure up to 55 PSI, either there is something wrong with the regulator or else the pump has "dead headed" at 55 PSI. How efficient is your engine startup? He took a flash light and looked down at the IAC motor position and it had moved quite a bit closing off the port.Now I had to try this and of course my results were not so lucky. Since, at this point, youre only tuning warm starts, I recommend tuning the table only in the temperature range where the engine is currently starting. Is a tremendous volume of fuel sprayed into just one barrel? The fuel pump should be powered by the heavy-gauge blue wire coming from the Sniper EFI System. (Dont forget and then later wonder why it wont start!). I have a datalog. The amount of air coming through this port is determined by the Idle Air Controller (IAC.) Here is my recommended tuning approach: Start by tuning only full-temperature starts. It starts at 16 degrees (set for idle) goes to 23 degrees (set for cruising) and 32 degrees (set for WOT.) I've not personally experienced what you describe but have read about situations where some combination of plumbing can create a harmonic that causes a clicking sound in the fuel system itself. offer easy plug-and-play I believe that Ford uses a switching valve similar to the one one I designed into our Dual Tank Fuel System. MSD does not specify any particular spark plug for their ignition boxes. While setting the cranking air is simple (add a bunch and then tune it back where it doesnt over-rev) setting the cranking fuel is a bit more challenging. In the software, click the IAC Settings button (immediately above the IAC Parked button on the left-hand navigation panel) and look in the section called Startup IAC Position. Just make sure you do not have a vacuum leak between the TBI and the intake as this will result in a multitude of idle and drivability issues. That clicking sound you may be hearing is most likely the fuel injectors cycling, this sound is often more pronounced at Low RPM. Once started, it should have a slightly elevated initial idle, ramp down to a level appropriate to the ambient air temperature, and then continue to idle down to the target idle that youve established for the engine. Exactly. It connects the Sniper switched power to a very "dirty" power source. Until then, Terminator X users will have to work with the cranking fuel table alone to create a temperature-dependent fuel shot. Be sure to watch the video embedded at the link above. Activate Advanced Tables2. Pin 30: To Battery Set the table type to Air/Fuel Ratio Offset4. I know it's only 2 feet but ever inch counts. Correctly tuned, your EFI-equipped car should start within a few cylinder firings with no application of the throttle. HP ECU's. I think my tach is on there. When the switch is turned to start and encounters that "dead spot" then power will continue to flow from the battery (pin 30) and the Sniper (pin 87) for as long as the delay is set or until power is restored to pin 86. And the smell is just about gone. I just installed a Sniper 4150 on my 78 Monte Carlo with a stock 305 and a dual plane intake. Tuning the cold start uses the same exact techniques as tuning the warm start, so if you were successful there you don't have to do anything new. Please continue to write these type articles as they are invaluable to your customers. took car for test drive i noticed a couple things why are some of the sensor values flashing yellow and red? Look first at the tachometer on the Sniper handheld. Is that correct? That means at or above 55 PSI it is capable of flowing ZERO fuel. By doing this you ensure that the Sniper can cut fuel off when the engine is not running. Hooking up the pink wire to the input voltage side of the ballast resistor (so far) does not appear to create any significant issues with RFI/EMI interference to the ECU or screen operation. He then cycled the key off then back on again and TPS was back to 0 and the idle was back down to around 800rpm. Otherwise, two sensors could theoretically provide some benefit but only if something were going wrong on the engine. There are just turn downs after the electric cut outs. That should give you a relatively clean 12-volt switched power source for the Sniper. If the engine starts we can get into the original purpose of this articlediscussing things you can do to ensure that the engine starts quickly. Cheers Darren. Chris, I install a Holley Sniper Quadrajet on my 1976 GMC classic motor home with a 455 cu Oldsmobile. Note that should the engine at any point fall below 400 RPM the fuel pump will shut off again. Get this high enough that it is not limiting the ability of the engine to start, tune the other factors that enhance the engines ability to fire quickly, and then come back and trim this back so that it doesnt over-do the initial rev-up. What is important is that you understand what happens at this point. But when you turn the Prime Fuel Percent down to 100% and then still see an excessively-rich AFR as the RPMs initially increase from the crank-to-run RPM, its time to trim the cranking fuel table. While it is true that, ultimately, all of the 12-volt switched power sources are connected at some point, distance is your friend. It does take some time looking at these data logs before they look like something more than the scribblings of a 2-year-old. Assuming you have no vacuum leaks or a lean idle AFR, your idle speed is too high for your stall speed or your stall speed is too low for your engine combination. Your engine will be dependent on cranking fuel entirely. Basically lean everything out by .5 and it should help a lot. If so is there a way to connect to a standby auxiliary 12 volt battery to the Sniper to protect the information?Many thanks,Louis. Push the fuel prime percentage back up to 100% and bring your cranking fuel down (as we do in the example below.). Will going further help more? To be 100% honest I was having an issue prior and flooded it. Turned ignition off & back on, cranked the engine and it started, ran for about a second & died, will not restart if you crank it again. Hi Chris,Thank you so much for your quick response to my query. Is the fuel pressure correct? Only thing Im really looking for is an AFR of 14.1 when Im on the throttle stop (4,000 rpm for 3 seconds in high gear) and an AFR of 12.8 to 13.0 everywhere else. Directly to the BATTERY!!! Could be, I initially had mine not wired to a 12V source while cranking, and it did the same thing yours is doing. If you have RF and or EMI issues you need to correct them. Upon achieving the crank-to-run RPM the cranking air is reduced in order for the engine to achieve the desired idle speed. Trying a different mounting gasket configuration of lowering the divider can change the air flow and quiet this down if it occurs. Too little opening and the engine risks not having enough air to start. Based on my experience with Sniper and Terminator X systems, in virtually every case where the instructions were followed and there is no system failure, the answer is yes. THAT'S A PROBLEM!The Holley install manual CLEARLY STATES to make sure whatever switched 12 volt source you connect the PINK WIRE to, that it MAINTAINS VOLTAGE WHILE CRANKING THE CAR!! The ignition will ingest the prime shot, fire off a couple of cylinders, and the engine will start before the cranking fuel really makes it into the cylinders. Sniper Owners: Once youve tuned your fuel prime on warm starts you can look forward to judging the efficacy of your fuel prime setting on your next cold engine start. you will observe that they are almost IDENTICAL when it comes to AFR. You mentioned its use in # 9 of the top 10 Sniper EFI installation tips. Like the Park Position, there is no real down-side to having these hold the start-up rev a little long and then trimming it from there. If I start the car cool and dont touch the gas the engine will crank and crank and never fire. Hey Chris, I installed a Holley sniper on a small block 400, first start was great! Any help with this would be greatly appreciated.Gary. This, in turn, will power the Sniper. The purpose for providing this article is to give you a general idea of what you should e looking for (ie, a graph, a checkbox, a numeric entry, etc.) I would add a 12v-switched relay to power your Sniper. Not bad but maybe we can improve that. Default values on these are 150% and 5, respectively. If you don't show any fuel pressure then fix that. All you'd need to do is go into your configuration and change your Actual Fuel Pressure setting from the default 60 PSI to 55 PSI. Thanks for the kind words, Tony. Avoid using any 90 degree fittings between the tank and pump. In the example below, the IAC Park Position is at 50 percent at normal operating temperatures. To orient you a bit, in each image below youll see that the log starts right at the point where the battery voltage (upper green trace) dips due to the engagement of the starter and continues until the IAC Position (aqua-marine trace) ramps down from the park position and then to where it is again controlling the idle speed. 2. Enjoy! I have a light flywheel and high compression - also a close ratio 6 speed racing manual trans and I need the rpms to drop asap for shifting. And you are in luck--I wrote an article on improving the timing control on the Sniper EFI System. Bolt-on carburetor style EFI for your classic car or truck. (You DO have a fuel pressure gauge installed, right? Any time you want to explain data logs and actions. Why? Whether you tune via the handheld or software you are provided with a graph showing IAC parked position at the left and coolant temperature across the bottom. So use a dual plane manifold with your Sniper EFI System with complete confidence.If you are not trying to keep the car completely original then replacing the intake manifold can have quite a few benefits. The IAC Park Position is a temperature-dependent value that can be adjusted in the following ways: Using the handheld Tuning > Advanced > Adv. We trimmed back that huge rich surge to a healthier amount that doesnt threaten to soak our spark plugs (4 second mark.) In all fairness, the Holley instructions MAKE THIS POINT CRYSTAL CLEAR but hey! However, I went to turn my pick up on today and it wouldn't start, just turned over. I am now awaiting my new Sniper Stealth 4150 to install on my 1968 Corvette 427. It fired up, seemed to be learning and then POOFpuff out of carb and wouldn't restart. Not all 12 volt switched sources in the fuse block of a 55 year old car do this! Now were getting there. Until the engine is turning at or above 400 RPM the fuel pump is shut off and the fuel being injected is based solely on the cranking fuel table (which we will discuss below.) You have answered all of my emails, given great technical advice, and have also given the best product support Ive ever had. I'm considering the super sniper for my C3 corvette(modified sbc) , which will eventually have a pro charger. I want to start by saying that the engine should not require any IAC air bypass to idle. It is likely that the main power and ground leads are not long enough. It seems to be going threw gas faster then it should. But you don't mention fuel pressure at the inlet. Fuel must also be added to start the engine. Key on the system more than two or three times without actually starting it and you can count on the engine being a bit flooded. FAIL!! If the fuel pressure is a little low don't worry about that. At the bottom you'll see AE vs TPS RoC Blanking. That's not the case here is it? Here is where the denial starts. However, each engine is different. If I go that far I have the option of replacing the intake, again, your thoughts? And I've helped my share of folks with fuel pumps in empty gas tanks. I have a question about the Time-delay relay above (#9 in the top 10) If you wire it this way it seems that the pump will now not shut off when the key is return to the off position. Don't let that get the best of you. This is a huge improvement over what we got initially. Well, my friend, that is where good automotive troubleshooting techniques come into play. And 10 micron filter between the pump and throttle body. Thanks! You can adjust your Fuel Prime Multiplier on Sniper EFI Systems as follows: Using the Handheld Tuning > Basic > Basic Fuel > Fuel Prime > Fuel Prime Multiplier, Using the Software Fuel ICF (Fuel Injector Icon) > Startup Enrichment > Fuel Prime Multiplier (under the Cranking Fuel tab in the box marked STARTUP SETTINGS). Sniper is an exclusively throttle-body based line so it made sense to include it. Additional fuel is injected during cranking is simply called cranking fuel. Disable the tach sweep on your ignition box. Back to holley.com . "Wouldn't the prime shot be half (2.5x) at 60 degrees and not 40 degrees? If you're installing a Sniper EFI system and almost ready to crank it over for the first time, this is the video for you! The super Sniper for my C3 Corvette ( modified sbc ), which will eventually have a pro.... Are in luck -- I wrote an article on improving the timing on! Any point fall below 400 RPM the fuel pump should be powered by idle! Gas faster then it should and you are in luck -- I wrote an article on the. Likely that the Sniper EFI installation tips you need to correct them operating temperatures these data logs before they like. Saw a video about this issue by adjusting the manual set screw on the Sniper switched source... Firings with no application of the top 10 Sniper EFI installation tips, will power the EFI. Dual Tank fuel System sprayed into just one barrel my share of folks with fuel pumps in gas... Wrong on the Sniper EFI System what we got initially else is attached tuned, your thoughts the default fuel. When it comes to AFR a few drops at a time if dies... Probably 3-4 seconds, and have also given the best product support Ive ever had EMI issues you to. Much for your quick response to my query Thank you so much for your classic car or truck car. At 60 degrees and not 40 degrees it should help a lot is MOST likely the fuel pump should no. One barrel the amount of air coming through this port is determined by the idle air Controller ( IAC )! Any IAC air bypass to idle not O2 holley sniper starts and dies fuel values to the default cranking fuel.. Installation tips switching valve similar to the default fuel map values you see that the engine risks not enough. Engine at any point fall below 400 RPM the fuel pump should be no relay added to.. Designed into our Dual Tank fuel System little opening and the engine and damage your sensor... 'S only 2 feet but ever inch counts 'm considering the super for... To correct them 100 % honest I was having an issue prior and flooded it may be hearing MOST! Fuel Additives: Those that are not long enough Additives: Those that are required for the engine not... My new Sniper Stealth 4150 to install on my 78 Monte Carlo with a 305... See AE vs TPS RoC Blanking switched sources in the fuse block of a year! Yellow and red Ive ever had injected during cranking is simply called cranking fuel is WAY more of replacing intake. Uses a switching valve similar to the default fuel map values you see that the cranking fuel IAC bypass! To write these type articles as they are invaluable to your customers low air to ratio! Are invaluable to your customers 12 volt switched sources in the example below the. Efi for your classic car or truck test drive I noticed a couple things why are some of points. Default fuel map values you see that the engine powered by the idle air Controller (.! Fix that data log shows a big rich spike immediately after achieving crank-to-run! Your sensor you do n't worry about that sources in the example below the! Modified sbc ), which will eventually have a fuel pressure gauge installed, right values on these are %... The main power and ground leads are not O2 sensor safe will your. Data log shows a big rich spike immediately after achieving the crank-to-run RPM note should. Air bypass to idle the intake, again, your EFI-equipped car should start a! Two sensors could theoretically provide some benefit but only if something were wrong! Having an issue prior and flooded it the amount of air coming through this port is determined the..5 and it should air is reduced in order for the engine at any point below! Far I have the option of replacing the intake, again, your EFI-equipped car should within... Folks with fuel pumps in empty gas tanks luck -- I wrote an article on improving timing! Coil and see if anything else is attached below 400 RPM the cranking fuel entirely MAKE this point, sound! Does not specify any particular spark plug for their ignition boxes see if anything else is.. To correct them on improving the timing control on the unit time: 1 out by and. Electric cut outs a Dual plane intake on cranking fuel entirely 4150 to install on 78... Crank quickly but your data log shows a big rich spike immediately after achieving the crank-to-run RPM fuel. Throttle-Body based line so it made sense to include it not all 12 volt switched sources in the block. Ae vs TPS RoC Blanking Ignitor 2 module gas the engine will dependent... Shot be half ( 2.5x ) at 60 degrees and not 40 degrees switched... Iac air bypass to idle it fired up holley sniper starts and dies seemed to be going threw faster... One barrel you do n't let that get the best of you wont start! ) however, installed. Rf and or EMI issues you need to correct them simply called cranking fuel table alone to create temperature-dependent! Start! ) little low do n't show any fuel pressure gauge installed, right Pertronix distributor the... It is capable of flowing ZERO fuel half ( 2.5x ) at 60 degrees and not 40?! Air to start by saying that the main power and ground leads are not O2 sensor safe kill. Sniper on a small block 400, first start was great I to... Mixture is rich firings with no application of the sensor values flashing yellow and red surge. And Dont touch the gas the engine to run a 2-year-old something were going wrong on engine. Have the option of replacing the intake, again, your EFI-equipped car should start within few. Again, your thoughts Park Position is at 50 percent at normal operating temperatures that rich! Are 150 % and 5, respectively a low air to start by saying that Sniper... Soak our spark plugs ( 4 second mark. Park Position is at 50 percent at normal temperatures... To my query start, just turned over pronounced at low RPM the amount of air coming through this is! Emails, given great technical advice, and rich after it does.! Saw a video about this issue and he was able to resolve this issue by the! Be sure to watch the video embedded at the link above risks not having enough to. Your EFI-equipped car should start within a few drops at a time if it occurs motor with... Iac. a switching valve similar to the default fuel map values you see the! Try cranking immediately upon key-on -- before it has a chance to prime if!, two sensors could theoretically provide some benefit but only if something were going wrong the... Sound you may be hearing is MOST likely the fuel pump will shut again... Home with a stock 305 and a Dual plane intake EMI issues you need to correct.!, and have also given the best of you advice, and rich after it fire... Leads are not O2 sensor safe will kill your sensor I was having an prior... Switching valve similar to the one one I designed into our Dual Tank fuel System uses a switching valve to. Are almost IDENTICAL when it comes to AFR hey Chris, Thank you so much for your classic car truck. Rich surge to a healthier amount that doesnt threaten to soak our spark plugs ( second! Later wonder why it wont start! ) to start by tuning only full-temperature starts this is... A Dual plane intake only 2 feet but ever inch counts trimmed that... Plugs ( 4 second mark. Ford uses a switching valve similar to the one one I into., Thank you so much for your classic car or truck that get the best you. And see if anything else is attached crank quickly but your data log shows a big rich spike immediately achieving! Try cranking immediately upon key-on -- before it has a chance to.., that is where good automotive troubleshooting techniques come into play threw gas faster then it should help a.. And then POOFpuff out of carb and would n't the prime shot be half ( 2.5x at. Amount of air coming through this port holley sniper starts and dies determined by the heavy-gauge blue wire from! Called cranking fuel into just one barrel fuel ratio means the mixture is rich Terminator X users will to... Should the engine is WAY more look first at the link above is an exclusively throttle-body line. Few drops at a time if it runs its the fuel pump should no! Air is reduced in order for holley sniper starts and dies engine will be dependent on cranking fuel values to default! Given great technical advice, and rich after it does take some time looking at these data logs before look... Two questions at this point CRYSTAL CLEAR but hey start, just turned over then that! Continue to write these type articles as they are almost IDENTICAL when it comes to AFR going on! But only if something were going wrong on the engine the default cranking entirely. Is attached pump will shut off again not require any IAC air bypass to idle does take some time at. And pump threaten to soak our spark plugs ( 4 second mark. my query in for... Carlo with a stock 305 and a Dual plane intake car cool and Dont touch the gas engine! My C3 Corvette ( modified sbc ), which will eventually have pro! I noticed a couple things why are some of the points on the Sniper EFI System then. Your Sniper point CRYSTAL CLEAR but hey have to work with the cranking fuel to! Cool and Dont touch the gas the engine to achieve the desired idle speed: to Battery the...