Designing a fuel system that can pick up fuel at all fill levels and with a nearly 90-degree angle on the tank is a challenge. Resistance results in heat and heat results in more resistance. Oil control: If you're burning oil you will kill your O2 sensor, closed loop chasing unstable fuel supply issues( see fuel pumps comment). Hi I am running a Hyperfuel pump part #40019 with a 58 psi regulator built in to the pump am I safe to run this with my holley xflow or should I be removing the fuel pump regulator and installing one on the return line? I would add a 12v-switched relay to power your Sniper. That helped. 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. We see a nice improvement in that big fuel dump as the engine starts running (between 3 and 4 second mark.) If the pump has a restricted feed or is mounted above fuel level and has to lift fuel you Will damage the pump do to cavitation. I believe that this compensates for the fact that during cranking fuel injection the fuel pump is not running. I am now awaiting my new Sniper Stealth 4150 to install on my 1968 Corvette 427. Too little opening and the engine risks not having enough air to start. That amount of air is determined by the IAC Park Position. Anouther cause may be the proximity of a dual plane intakes plenum divider to vacuum passages under the throttle body resulting in an odd sucking or whistling sound. When the injectors open to spray fuel the pressure might drop enough to allow a few drops of fuel to flow, but nothing near what you're going to need. Oxygen sensors read unburnt Oxygen not Fuel. If you shorten the harness, not only are you likely to damage the sensor you probably just short circuited your ECU. In virtually all cases, this will be more than the amount of air it needs to idle. I have and will continue to recommend EFI System Pro due to your outstanding services and customer support. First, remember that after-Start enrichment is not a fixed value. How fast will the programing in the sniper be , in order to take advantage of a sudden open exhaust situation ? At that point you can start taking the AFR readings into consideration IF the engine seems to be running smoothly. Quick to respond and very knowledgeable. The IAC Park Position is a temperature-dependent value that can be adjusted in the following ways: Using the handheld Tuning > Advanced > Adv. Nobody ever thinks to do this but one of the best tips for confirming that you don't have an issue with your Sniper fueling is to remove the breather, get in a position where you can see all barrels, have someone power on the system, and look for an equal quick spray of fuel in each barrel. My car idles beautifully @ about 800rpm. The setup wizard offers three cam choices for Stock / Mild ( 14+ In/HG vacuum ), Street / Strip ( 8-13 In/HG vacuum ), and Race ( 7 or less In/HG vacuum ) More aggressive camshaft grinds will likely require laptop tuning with the aid of the Sniper Software in general engines . It was originally there more as a vent than a return and is inadequate in size to use as a return. If this is your situation then first install a brand new set of spark plugs to rule out any fouling-related misfires. That is sort of a long shot but more-and-more I have folks give that a try because sometimes it corrects mystery problems that don't have any other explanation. Failing to do so could result in a very dangerous situation if the fuel pump kept running when a fuel line were cut in an accident. I am letting it set over night, cleaned plugs as well. Nothing else (except gas), In a no-start situation my direction is always the same. At -40 degrees it multiplies it by the full indicated amount (five times, by default.) Last time it ran was last week and it ran fine but I believe I ran out of gas or was close to running out of gas while idling in my driveway. Be sure to properly gap your plugs and if you plan to run Magnetic pickup distributors for timing control. Nor can I really recommend that you split it as I have. features . 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. How to Tune Acceleration Enrichment in Holley EFI // Terminator X, HP, Dominator & Sniperonce again, i made a video too long. Bolt-on carburetor style EFI for your classic car or truck. So I can't tell you what TPS to use. How will this setup work? At least not right away (after time-delay set in relay). In a nutshell, you do the following:1. also i returned from test drive exhaust seemed clean at idle at first then seemed to go rich, any help would be greatly appreciated.Also, I have long tube hooker super comp headers the only place i could mount the sensor is 10" past the end of the collector , one of the post said i could go into tune up program and change the poramater from 3 to 1 is the correct? After-Start enrichment tuning is even more multi-faceted than cranking fuel tuning. 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. I have read and re-read all of the info about the idle issues and I have no idle issues on first start up to running temp of 190 degrees. Now that were up and running lets go deeper and see what can be done to improve things. Is the sniper compatible with my distributor? Holley Sniper First Start. 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!! I have a 88 f150 302 with factory efi and dual tanks. Am I following this correctly or not? If not then stop and buy one now. Then he put his thumb back over the IAC port and there was very little air passing through the port and the loud sucking sound was gone. If you are running a fuel cell with two ports in the sump, do not run the return into the port parallel to the feed. Gary. Compression, properly metered fuel, correctly timed spark. You also need to properly phase the rotor. Turn your prime shot down (I think I run about 75% and NEVER let it fire its prime shot when the engine is warm. . 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. My car is going on the dyno for final tuning next week. Thanks. 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. Then, realize that you have the ability to delay the point at which the enrichment starts by up to one second. If you've upgraded your engine significantly then you may need to upgrade your fuel pumps as well. Any tips or info on cold starts? And that from a not-so-shabby original 1.13-second start time. 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 I seen it said to wire the blue wire not to the 12v accessory which I do understand. If your engine starts well, sounds good during the hold, but then fails a bit after the decay you can extend these out a bit. Most important!!! 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. My problem is that it starts and stalls instantly then acts flooded. Thanks. This helps ensure that any trash that might have been in the line somewhere is swept somewhere other than into an injector. This is a bit tricky. In my experience startup fuel tends to be too much. Take a hot summer day with radiant heat soak out in the sun and the fuel can be near or exceed its boiling point in the tank. I see folks debating this so let me say unequivocally that the Sniper WILL NOT WORK on an engine if the Sniper is trying to get its RPM signal from the ignition. That is not the case. "I've edited the article with a note about the difference. You write: "The fuel prime multiplier multiplies the fuel prime shot amount based on temperature. There is a correct setting for the idle and it sound should not be a consideration. 03-14-2018, 07:03 PM. (Note: The observant reader will note that the paragraph above is not mathematically correct but is exactly as is provided in the Sniper tuning manual. Sniper is an exclusively throttle-body based line so it made sense to include it. It needs to have a 80-100 micron pre-filter installed between the tank and the pump. A low air to fuel ratio means the mixture is rich. Another great dissertation. Lets dig down into that a bit and see if we can help. Lets go back to 100% fuel prime and turn cranking fuel down in that region by 30% and see how that affects us. I am running a wet exhaust with O2 sensor plates. Many of these are completely normal with EFI. 2-Barrel Sniper EFI 2300 Sniper EFI C10. 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. The Sniper EFI System is not capable of monitoring two O2 sensors but neither is that generally necessary. Increased power at the plug gap improves the combustion process of the fuel mixture which in turn improves the efficiency of the engine and performance. If, after starting, the engine speed drops below the crank-to-run speed it turns the fuel pump off again. Anytime the built-in Sniper fuel pressure regulator is not used the return can simply be plugged. Hey Chris, just finishing up my Sniper 41504BBL install with in tank pump / no return line from EFI neededdoes the fuel line need to be bled up to the 4150? 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. I have it disconnected to flush any debris out.Thank you. It drains the battery almost dead then will fire up. These settings will be instrumental to a fast start. Is the fuel pressure correct? Latest Articles. Words only go so far so I thought Id include a tuning session to give you some idea of whats going on here. It worked fine with carb, hope someone can help. May God's grace bless you in the Lord Jesus Christ. Enable a 1D table3. How did you install the return line to the tank? Therefor, -40 + 100 degrees = 60 degrees. In fact, MOST of the points on the fuse block don't do that! With the engine at full operating temperature you should be able to stick your finger in the IAC inlet port on top of the throttle body and the engine should simply idle down about 50 RPM below your programmed idle speed. Tried the Holley forum but The manual states that this signal should not be split. EFI doesn't have feelings--it doesn't care what cam you use. If not then you'll need to key the engine off and back on to get the fuel pump to prime again. Can I use this for the return.Thanks for the help, I have rock crawler on propane will the sniper EFI with the right fuel system work with nasty angles and articulation ? Realize that what happens when you're playing with this on a cool morning with no load on the engine is not the same as what's going to happen when you are in other conditions so make your changes gradually and spend a good amount of time proving them. 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