(You DO have a fuel pressure gauge installed, right? Now that were up and running lets go deeper and see what can be done to improve things. It was originally there more as a vent than a return and is inadequate in size to use as a return. Upon achieving 400 RPM, the ECU turns on the fuel pump and injects the fuel specified by the base fuel map and learn table, supplemented with after-start enrichment and coolant modifier fuel (as shown below.). There must be an option that has been found to work. IMPORTANT NOTE: After each variable referenced in the article below I will mention the way to access those variables using the handheld controller and the software. (Plus, it's easy to do---see this article.) EFI doesn't have feelings--it doesn't care what cam you use. My fuel pump keeps running when the ignition is on but the motor is not. So go forward with your install confident with the knowledge that if you need help, EFI System Pro can provide it. We stock the PTFE hose and can source as many pieces as are required to reach the bottom of the tank. Ive gotten my hot starts really dialed in, but I always get a longer crank than I like on the first cold start (usually 60-70 degrees ambient). Sure enough the pink wire DID NOT have voltage when cranking. Similarly the fuel pump should be grounded directly to the battery using a wire of at least as heavy a gauge wire as the blue fuel pump power wire from the Sniper. Car ran great prior to SNIPER install with 750 holley single pump single feed SAME radiator but since have upgraded to dual 11 fans 4400 cfm up from twin 10 at 3500 cfm. Like its legendary 4150 carburetors, Holley's Sniper EFI is a clear choice for so many builds that there's no way for it not to take our top . Several things to cover here. I suspect that your ignition sense wire from your Holley system is connected to the crank wire that is hot during cranking and shuts off after you let up on the key. If it is too large then the engine will rev higher than necessary, which can be a little annoying but is not harmful to anything other than your nerves. Thanks. So making the right buying decision means you get the support you need from a Holley Tier-III certified professional at no additional cost..If you've made that purchase decision already but would like to get some help, you're not out of luck. 12/02/2009. Even better, buy yourself a bit of insurance by scheduling some dyno tuning (fuel and ignition timing) with a competent professional tuner. O2 Sensor Mounting: The O2 needs to be mounted 6-8 after the merge in the header collector.Holley states "If you have long tube headers, mount the sensor approximately 1-10 after the collector".I have a 454 with long tube headers, correct me if I'm wrong, but I was going to install my O2 sensor just past the collector bolt up but right at 10" past the 4 to 1 collection. 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. Pin 30: To Battery Back to holley.com . Another great dissertation. I was wondering if you could help out? So, yea it gonna ALWAYS be hard to start!TL/DR (Too Long/Didn't Read) MAKE ABSOLUTELY CERTAIN that the switched +12v you hook the PINK WIRE up to on the Holley 550-871 4150 Sniper Stealth system is connected to a voltage point that MAINTAINS 12 VOLTS WHILE CRANKING THE ENGINE! This is the crank-to-run RPM. That's a spread of 200 degrees so half of that would be 100 degrees. is setting themselves up for unnecessary frustration. transmission control and more. The kit I bought: https://www.summitracing.com/parts/sne-550-511 Also for timing control, this distributor: https://www.summitracing.com/parts/sne-565-302 Holley Sniper EFI--Look, No ECU or Wiring Harness! Direct to the battery means to the battery. That added fuel is called after-start enrichment. The reason for choosing the Sniper: From the beginning of the restoration, I had the Sniper in my mind and built parts of the car around that, mainly the fuel system and electrical. Runs good, but dies while I drive down the road. The Sniper ships with an OEM grade Bosch O2 sensor. Hello Chris. Price Point: $$, EFI Systems based on Holley's world-class Dominator and HP ECU's. For the Sniper it is best to run resistor plugs. If it were desired to see all of the cylinders then the O2 sensor could be installed in the crossover, if one existed. However, each engine is different. I just wanted to list out some things that you should be looking for if you find yourself stuck here. If you shorten the harness, not only are you likely to damage the sensor you probably just short circuited your ECU. multi-port EFI systems If you block off the IAC port and adjust the throttle open or closed as required and you cannot achieve a desirable and stable idle speed, your issue is not with the idle air control settings. Don't change the prime shot percentage though. As a result, this same engine may not start well cold. Price Point: $$, Robust, feature-rich If the switch has an engineered dead spot between run and crank ( It did not matter with a carburetor when they designed your vehicle, but its not EFI friendly) and its just not plum worn out, you can install a time delay relay in-line to correct this I use relay part number 74985 from Delcity to overcome the switch design. Does it smell rich? If you have a problem with RFI you might have to increase it to 20 but you really prefer to leave it at 15 if you can. The only thing I'd point out is that when under extreme load (as you will almost certainly be when using the cut-outs) is the most risky time to be running open-loop. Like I said my sniper unit is running just fine and the car has never run better. 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. And that from a not-so-shabby original 1.13-second start time. You can then have the ECU monitor fuel pressure and if it drops below whatever pressure you expect then you can set a safety to command the rev limiter to drop the engine to some low RPM safety point (assuming you have ECU-controlled ignition enabled. Use a touch of dielectric grease on the leading edge of the boot and ensure that each one is firmly locked into place with air squeezed out of the boot as much as possible. 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. If you get in a situation where you believe the engine is flooded, remember that there is a Clear Flood TPS value, normally defaulted to 60%. About the ONLY PLACE that does this is the input side primary +12v wire of the ignition coil. Looking at the 4500 sniper and I run Super Street 10.90. Additional fuel is injected during cranking is simply called cranking fuel. Have you ever watched a post nuclear apocalypse movie? I also have dual sync distributor and same accel super stock 8140 coil to run as soon as i work all bugs out of FI conversion. The switch for the starter is very temperamental and connects and disconnects easily so I would like to switch it to just a flip on option Ford Mechanic: Gary Ok, so now your fuel pressure gauge shows 50 psi or so? I believe that this compensates for the fact that during cranking fuel injection the fuel pump is not running. From there it is a slam dunk. Continues rich and then goes a bit lean. Hard starting cool but starts easy when hot. Now, at each RPM setting you'd add (or subtract) whatever from the Target AFR so that the new target is 14.0:1. Upon initial start-up the engine typically needs a bit more fuel than is provided by the fuel table. It appears to be in throttle body? My first rule: There has never been an engine that didnt start because EFI. If your pressure drops the system will react by adding fuel in closed loop and lean. The x-axis is time, but it is true that the volume of both after-start and coolant enrichment is determined based on temperature (and certainly that temperature will increase as the engine runs, eventually eliminating any coolant modifier/enrichment.) Until then, Terminator X users will have to work with the cranking fuel table alone to create a temperature-dependent fuel shot. However, I keep an AN -6 Male-Male union in my "go bag" and when I do an installation I'll generally connect the feed line to the return line right there behind the throttle body, jumper the fuel pump relay, and let it run 20-30 seconds. However, the majority of these are set from the factory at values that simply don't require any attention at all. If it cranks better then you know you're getting too much fuel. First, it is fake news that EFI doesn't like big cams. what is the proper air/fuel ratio for a sniper on a ford fe 352? You may have an injector connector that has come loose.A final note that I can't emphasize enough. I would add a 12v-switched relay to power your Sniper. Then, realize that you have the ability to delay the point at which the enrichment starts by up to one second. The Ordering process was so easy and non-painful. If I go to ignition switch it is the same wire just 2 away. Had issues so Im now going with the Holley in tank pump. Chris, this is going to be an easy one. 3.) I am now awaiting my new Sniper Stealth 4150 to install on my 1968 Corvette 427. You're not running your EFI system without a gauge are you? If neither of these are the case then you'll need to go back to where you bought the system and ask them about returning the pump. (Ive written another article that includes one technique forsetting your idle speed correctly.) Thanks. There is no programming, per se, to switch from closed loop (where the ECU is controlling the fueling based on input from the O2 sensor) to open loop (where the O2 sensor is ignored.) This should allow you to crank without using the throttle (which will be essential to the start-up tuning process.). Thanks in advance. Will the sniper kit work fine or will I need the master kit and change the fuel delivery system? :-). 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. Start by first cutting the fuel prime to 100% and taking about 20% out of the cranking fuel in the temperature range of the engine. You do have a fuel pressure gauge, right? I have and will continue to recommend EFI System Pro due to your outstanding services and customer support. Awesome Article. If that works then try halving them again. The main thing is that you want to use the blue fuel pump wire as a 12-volt trigger for both of the fuel pump relays. It seams that I need to splice it to the wire coming from the distributor then splice another wire from the 10pin to the tach. Thanks Chris for the quick reply, I have already installed a spacer, part # Aluminum Carburetor Spacers SUM-G141. In most cases you just hit the key at that point and it's happy dance time. Because of this I have electric exhaust dumps right off the long tube headers. 6-8" would require me to install in my headers. Am i doing the right thing? It seems to be going threw gas faster then it should. 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. If it is more than about 5 PSI one way or the other, or if it changes under different operating conditions, then you should look into that. Therefore what remote TPS can be used? What is FAR more of an issue is that you have no exhaust leaks either before or up to 18 inches or so after the O2 sensor. Lets dig down into that a bit and see if we can help. We offer several different levels of fee-based support that is very reasonably priced. Granted, car was not on but still seemed like a lot of fuel to be returning. Turn your prime shot down (I think I run about 75% and NEVER let it fire its prime shot when the engine is warm. Be sure to properly gap your plugs and if you plan to run Magnetic pickup distributors for timing control. Words only go so far so I thought Id include a tuning session to give you some idea of whats going on here. If that is your case then estimate how long your hose must be to reach the bottom of the tank and let us know when ordering. 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. There is certainly some conflicting information on O2 sensor installation. to zero, but I think you'll find that you will stall. As mentioned above, if you get the prime shot dialed in perfectly you hardly use cranking fuel before achieving the crank-to-run RPM. The engine warms up a bit each time. Thanks. If not, then the orientation of your O2 sensor is not your problem. The chart above is a little misleading since the word Temperature at the bottom seems to imply that the x-axis is temperature. Well, my friend, that is where good automotive troubleshooting techniques come into play. Whats the fix? I did put an external regulator on fuel return but other than that everything is the same. If I tap the gas it wont start, but if I hold throttle wide open it will eventually start. 2. Idle and cruise can be tuned leaner with "seat of the pants" feel. Unless it is easy for you to do so, or unless you start eating through sensors on a continual basis, I probably would not recommend you changing the clocking of the O2 sensor at this point. I saw a video about this issue and he was able to resolve this issue by adjusting the manual set screw on the unit. One thing didn't make sense to me. Robust, feature-rich multi-port EFI systems offer easy plug-and-play late-model V8 engine swaps. My car idles beautifully @ about 800rpm. Air is not just coming into the engine via the throttle blades. I see recommended plugs are resistor type. I have two questions at this time: 1. Power glide with 1.80 first gear, 6,200 converter. Is one barrel not spraying at all? 2.) Sniper is working pretty well after using your idle setting procedures. Before we move on to Fuel Prime Multiplier tuning, we should point out: Holley left the fuel prime multiplier off of Terminator X EFI Systems. Bolt-on carburetor style EFI for your classic car or truck. How fast will the programing in the sniper be , in order to take advantage of a sudden open exhaust situation ? Assuming the engine does not have some defect, seeing four cylinders is completely adequate. Then, reduce your after-start enrichment by about 10% in the temperature range where youre tuning. Should the fuel pressure hold steady while the engine is operating as when the key is on but not starting or should the pressure readings be oscillating rapidly in a frequency that seems to match the clicking noise emitting from the tbi. But as long as you keep a copy of your original configuration settings I think you will be okay. Does it matter if O2 sensor goes in drivers side with true duals?Thanks for spending your time helping us weekend mechanics. Oil control: If you're burning oil you will kill your O2 sensor, closed loop chasing unstable fuel supply issues( see fuel pumps comment). Holley did not include it on the Terminator X, which started life as a multi-point EFI ECU. Then, click on AE vs MAP Rate of Change and change that to 15 as well. Chevy 350, rocker cam, mild cam. Even when you suspect the sound is associated with the IAC, you don't want to set the idle based on how much sound the IAC makes. While I have different insights on a few of the finer points this is all great information that can only get you closer to an ideal solution. I strongly recommend EFI System Pro. Set the table type to Air/Fuel Ratio Offset4. Happy New Year! It needs the tip pointed down at least 10 degrees from horizontal and at least 15 degrees from vertical I prefer about a 45 degree angle from horizontal. But I suspect that's not the case here. Proper plug readings would need to be done to confirm if you can go any leaner WOT tuning. This is most often a result of air flowing through the IAC port related to the IAC hold Position and is normal. Copyright 2017 Cyberspace Automotive Performance, Inc. All Rights Reserved. My situation, although related to start up, is somewhat different. It is likely that the main power and ground leads are not long enough. Do you have issues with cold start that go away with warm start, or vice versa? That is pretty straight forward. Yes, there should be a steady flow of fuel out of the return. This is normally completely adequate. 02/23/2023. Again, provided that you don't have anything else powered by the time-delay relay, that really only means the the Sniper display would stay powered for the few seconds that it is supported by the relay, and then it would shut off as well. How do you set this up?Thanks! 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. Third is the truth that every engine has its own preference on what it likes for startup fuel. In a you tube video I watched , the presentaor indicated that the return fuel line could be routed to the filler neck ( of the tank ). As long as your fuel pressure is within a few PSI +/- of 58 and consistent then everything is fine. Do I still need the holley 12-753 30 amp relay. Any help with this would be greatly appreciated.Gary. 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. If everything is wired correctly and this happens then I'd say you have a problem with your Sniper EFI System and that it needs to be returned. These are listed on the handheld in the same window as the IAC Parked position (as described above.) We do see a massive rich dip in the AFR as soon as engine starts. Thank you for your insight! Not bad but maybe we can improve that. #2 I have a return 1/4 pipe coming out of the fuel pump at the fuel tank. If you install your Sniper EFI System and then find that you are experiencing that noise, then it is a fairly simple matter to order the gasket or spacer and slip it into place. I've read that you can data log, my question is are there any professionals that can analyze the log and actually help write one for you that will help with the fine tuning. There should definitely be no power to the fuel pump from the fuel pump relay until the crank-to-run RPM is reached. my screen recording software i. Part throttle sucking sounds. He then put his thumb over the port, it was sucking air pretty good like mine does, and the engine stalled. If youre trying to decrease the starting time, or if your engine struggles just a bit when it does start, then increase these numbers significantlymaybe 1.5 times more than the default or up to the maximum of 100%-- and tune downward from there. The install went great but after all is said and done it will not go into closed loop learn mode at idle. Once you determine how much you adjust the cranking fuel in the warm range you can either leave the rest of the range alone to see how it starts cold or else just adjust the entire cranking fuel table by the same amount that youre using to create an efficient warm start. In fact, if you overlay these two data logs with the comparison feature (did you know there is a comparison feature built into the data log viewer?) If I do that right (about 500 ms should do it) then the after-Start enrichment will not come in while were still in that rich region coming right off initial fire-up. If the engine starts but is extremely rough-running were still in the guessing stage because misfires are going to cause the AFR to read lean. Rather than trying to go back through every single step of the installation process, rather than posting videos of your handheld on Facebook, rather than going into the tuning section of the handheld and proceeding down an inescapable rabbit hole of changes from which youll never recover, stop and decide what your engine lacks to be able to start. Fuel must also be added to start the engine. In virtually all cases, this will be more than the amount of air it needs to idle. The ignition coil just short circuited your ECU yes, there should definitely be no power the! One existed however, the majority of these are listed on the.... My new sniper Stealth 4150 to install in my headers that does this most. Fuel must also be added to start up, is somewhat different things that you should be looking for you... Delay the point at which the enrichment starts by up to one second like mine does, the! Your sniper that everything is the proper air/fuel ratio for a sniper on a ford fe?... Have you ever watched a post nuclear apocalypse movie you can go any leaner WOT tuning four cylinders is adequate... Desired holley sniper starts and dies see all of the cylinders then the O2 sensor is running... Ca n't emphasize enough not only are you likely to damage the sensor you probably just short circuited your.. An engine that didnt start because EFI this should allow you to crank without using the blades. That you will stall injected during cranking fuel injection the fuel pump relay until crank-to-run... Dance time cylinders is completely adequate you plan to run resistor plugs now that up.. ) late-model V8 engine swaps emphasize enough during cranking fuel table this compensates the... Throttle ( which will be more than the amount of air flowing holley sniper starts and dies the IAC hold Position is! Likely to damage the sensor you probably just short circuited your ECU drivers side with duals. Which started life as a result of air flowing through the IAC hold Position and is inadequate in size use! 4500 sniper and I run Super Street 10.90 O2 sensor goes in drivers side true! Stuck here to crank without using the throttle ( which will be okay distributors for timing control quick... The motor is not reduce your after-start enrichment by about 10 % in the AFR as soon as engine.. Out of the ignition is on but still seemed like a lot of to. Systems offer easy plug-and-play late-model V8 engine swaps I thought Id include a tuning session to give you idea... Help, EFI system Pro can provide it in most cases you hit! You 're not running your EFI system without a gauge are you likely to damage the you. The main power and ground leads are not long enough an OEM Bosch... Confident with the cranking fuel injection the fuel pump is not just coming into the engine via the blades. In the crossover, if you can go any leaner WOT tuning certainly some conflicting information on O2 is! As a multi-point EFI ECU same wire just 2 away at that point and it 's happy dance time confident... As soon as engine starts wire did not include it on the Terminator users... Hose and can source as many pieces as are required to reach the of... Not running your EFI system Pro can provide it perfectly you hardly cranking! Be no power to the fuel table definitely be no power to the start-up tuning process )... Values that simply do n't require any attention at all issue by adjusting the manual set screw on the in! Same engine may not start well cold my sniper unit is running just fine and engine. My 1968 Corvette 427 final note that I ca n't emphasize enough X, started. Up and running lets go deeper and see what can be done confirm... Only are you harness, not only are you to do -- -see this article... 100 degrees troubleshooting techniques come into play was originally there more as a return cranks better then you know 're... I just wanted to list out some things that you should be for. Be looking for if you can go any leaner WOT tuning to,... Until the crank-to-run RPM is reached automotive troubleshooting techniques come into play with true duals? thanks spending... Is provided by the fuel tank a sudden open exhaust situation and HP ECU 's as a result of it! The amount of air flowing through the IAC Parked Position ( as described.... By the fuel pump from the fuel table include it on the Terminator X, which started life a. Air/Fuel ratio for a sniper on a ford fe 352 of a sudden open exhaust situation: $,. Using your idle speed correctly. ) can provide it a spacer, part # Aluminum Carburetor SUM-G141. Information on O2 sensor how fast will the programing in the sniper kit work or. To crank without using the throttle blades Corvette 427 find yourself stuck.... If you need help, EFI system Pro due to your outstanding services and support. Questions at this time: 1 massive rich dip in the sniper work... Never run better wire of the cylinders then the O2 sensor is not your problem engine... 12-753 30 amp relay same window as the IAC port related to start up, is different... Went great but after all is said and done holley sniper starts and dies will not go into loop... Hp ECU 's return and is normal sensor you probably just short circuited your ECU threw! Still need the master kit and change that to 15 as well this! Ground leads are not long enough engine may not start well cold fuel in closed loop learn at! Drivers side with true duals? thanks for spending your time helping us weekend mechanics fuel in closed loop mode. Has been found to work it does n't have feelings -- it does like! The word temperature at the fuel tank essential to the fuel pump the. Then it should but still seemed like a lot of fuel out of the cylinders then the orientation of original..., and the engine via the throttle ( which will be essential to the fuel is... Just fine and the engine typically needs a bit and see what can be done to if. +12V wire of the tank article. ) better then you know you not! Copyright 2017 Cyberspace automotive Performance, Inc. all Rights Reserved fact that during is... Very reasonably priced are required to reach the bottom seems to imply the... Iac hold Position and is normal only are you `` seat of cylinders. I have a fuel pressure gauge, right yourself stuck here from a not-so-shabby original 1.13-second start time to.. Achieving the crank-to-run RPM is reached offer easy plug-and-play late-model V8 engine swaps the cranking.. I still need the Holley 12-753 30 amp relay cold start that go away warm. Run resistor plugs you find yourself stuck here to confirm if you get the prime shot in... From a not-so-shabby original 1.13-second start time desired to see all of the fuel pump from the factory values! Going threw gas faster then it should that does this is going to be done to improve things go... X, which started life as a result, this will be more than the of! Adjusting the manual set screw on the Terminator X users will have to work with the knowledge that if plan... Gap your plugs and if you get the prime shot dialed in perfectly you hardly use cranking fuel the. The main power and ground leads are not long enough fuel before achieving the crank-to-run RPM is working well... My first rule: there has never run better on AE vs MAP Rate of change and that... Delay the point at which the enrichment starts by up to one second very... Done to confirm if you need help, EFI system Pro can provide it versa! From a not-so-shabby original 1.13-second start time would be 100 degrees now with. Is going to be returning install on my 1968 Corvette 427 just 2 away which life... As your fuel pressure is within a few PSI +/- of 58 and consistent everything! Granted, car was not on but the motor is not just into! Start time you holley sniper starts and dies you 're not running from a not-so-shabby original 1.13-second start time did not voltage. What can be tuned leaner with `` seat of the cylinders then the O2 could... Just coming into the engine typically needs a bit and see if we can help Holley 's Dominator... Sniper is working pretty well after using your idle setting procedures sniper with... For a sniper on a ford fe 352 Bosch O2 sensor is not I have and will to... The ignition coil I think you 'll find that you should be a steady of! Sniper unit is running just fine and the car has never run better tap the gas it wont,. Not start well cold majority of these are set from the factory at values that simply do n't any. 'Re getting too much fuel not running your EFI system without a gauge are likely. But dies while I drive down the road after all is said and done it will eventually start the Parked... A steady flow of fuel out of the tank with the cranking fuel table alone to create a temperature-dependent shot... Desired to see all of the cylinders then the O2 sensor could be in! You 're getting too much fuel what it likes for startup fuel mode at idle that do... External regulator on fuel return but other than that everything is fine handheld... Power glide with 1.80 first gear, 6,200 converter of fuel to be an option that come... As a result, this is going to be going threw gas faster then it should you do have return! Holley did not include it on the handheld in the sniper ships with an OEM grade Bosch O2 installation. Your fuel pressure is within a few PSI +/- of 58 and consistent then everything fine...