Your AFR is pegged lean. Repeat until that stumble goes away, and then try a bit more throttle. Suddenly, the engine accelerates alone, hears a great deal of air being sucked in, Generally, one of two things: a stuck throttle or noise on the TPS signal. If I rev the engine a couple times in neutral it will finally return to idle & usually will not do it again for the rest of my trip. I would not expect that an electric fan would create a noticeable load on the engine but if it did then you'd want to set the idle screw when the fan was not running. I think that your Sniper system is working fine but would definitely check ouf the fuel pump. If I cruise down the road at lets say 60 mph and lay into it, she will take off and go. The Sniper ECU can use the timing to help maintain the idle speed and that will definitely be useful in that transition from Park/Neutral to Drive.If you don't have ECU-controlled timing, or if you do and it's not fully compensating, it may be necessary to increase your target idle slightly. Capability Range: Moderate No air should be able to pass. I recently bought the car with the EFI system on it. This increased idle speed is triggered by grounding the orange wire in the 10-pin I/O harness. Wish I had bought my sniper from you, but unfortunately didnt. I'd really appreciate some help. I haven't driven it for the 30-40 minutes like the several times it idled at 2200. I installed the Sniper on my 1978 Ford F-100 with a small block At this time, TPS is 0%, IAC is 50 to 60%. It is how the engineers allow you to clear a flood condition when you detect it. This only happens when coming to a stop and the idle is ramping down to the set idle RPM. I have an entirely separate article on Solving RF Intereference Issues. If you do find you have RFI issues then I've written an . If the minus 40 degree setting is lower than the setting to the right, simply move it up so that it looks something like this: The folks who have tried this have found that their idle speed control behaves much more as they expect. So, this is what it takes to put a Sniper on a small-block Ford. The broad consensus has been that the Sniper is an amazingly straight-forward install and starts and tunes as expected. Possibly cap, rotor, coil? I have verified that there are no vacuum leaks, not to mention the car runs to good to have a vacuum leak bad enough to make this noise. My Sniper is 99% great! Hello Chris. 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. i'm having is I can't seem to get the truck to run faster than 45 mph at speeds Now that you've installed at least four Snipers it is going to be imperative that you learn to create and read datalogs. When I see that your TPS is 1%, that tells me that you may have an RFI problem. We have never had that problem with any of the units that we have shipped. I will try the other stuff when I get off work. Good afternoon Chris, thanks for taking the time to help all of these folks that didn't purchase from you- myself included!The issue I seem to be having is at idle in both park/neutral and drive. Initial thought is timing but Im running a cd box and the ecu is not controlling and I did not physically change it during the install. I had HIGH Idle issue and fixing this curve FIXED the ISSUE --- THANK YOUCan you explain what "Current Learn % means, after finally fixing the idle problem this % jump from -1 to -30% in about 5 minutes at idle with CTS @ about 170.Also when starting the car at hot the engine goes to about 2300+ RPM for a few seconds then crashes down to my Hot idle speed of 950 -- bounces a little and then smooths out. Clearly, something is changing. that my Air/Fuel ration was 15:1 and I believe the target is 13.5:1. What might cause the TPS to go to 2%? The only way to confirm RFI problems is by doing a data log. Yes, let me know how that setup process works. I have seen a couple of videos on you tube of the same issue but they don't seem to have found the cure.I hope it is not a computer problem as I have already replaced the entire system because of another problem. If it is not a problem with the Sniper EFI System itself then it could be an issue with some sort of harmonic involving the fuel pump. Intake has been on and off 3 times no change. Supports up to 650hp with Four 100 Lb/Hr Injectors! I know this is old, but I bought and installed a Sniper kit in 9/18. Tuning > Advanced > Adv Idle > IAC Startup We've already tried adjusting the Acceleration Enrichment chart in all ways, going up and down, RoC Blanking, everything, it has no effect. Ive also used another snap on light to confirm. I have driven car about 200 miles. A question I cannot get a 100% answer on is can you piggy back off the Sniper EFI TPS for an electronic transmission? If the IAC number is increased during this high idle, review the points about high idle from tuning issues. Turning it off and back on would reset it, and then it would work as advertised for a while. 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. At low levels RF interference will often reset the ECU so quickly that the engine will not stall. The link above includes the option to buy a -6 AN = 2.34 I, too, wish you'd bought your Sniper from us! Any ideas here? Jump on board now! He is able to get it to start by quickly depressing the accelerator to at least 60% and releasing. In the wizard I set my Idle to 500RPM but it never got slower than 800RPM, if I run the wizard again and lower to 400 RPM then it never gets lower than 700RPM.After reading about the Idle Speed curver I checked its settings and found that the curve was 300rpm faster at every point over the temp range no matter what temp I had, I adjusted the curve to match what I put in on the wizard and now the RPM is correct, I'd say you have a bug in the wizard.Idle Speed > Idle Speed Curve: Here is where the lack of coolant temperature is going to affect you. If this is the case then some adjustment of the linkage or the butterfly plates themselves is necessary. engine works beautiful, the car runs a lot, but suddenly, the engine does that. And if you're going to go this route I'd recommend that you switch from "Simple" (3 A/F targets, one each for Idle, Cruise, and WOT) and go to the 2-D Table Replacement Idle Air Control (IAC) Motor for Sniper EFI TBI Systems, Sniper 90/92/102mm Throttle Bodies, Terminator TBI, Avenger 4bbl TBI, HP 4bbl TBI, Commander 950 & Digital Pro-Jection Systems. It is probably that your RPM above the maximum point at which ramp-down can occur. That way you can get into that part of the table that needs tuning, and you can watch your learn numbers grow. Check the Distributor Tach Connection to the EFI. A problem since day 1 - YouTube Leave a comment if you've had this issue and how you resolved. Find a lower price anywhere and we'll beat it by 5%! You might have a bad O2 sensor, really bad exhaust leak or a problem with the ECU. Between the kick down and the return springs on the throttle body the pedal is so hard to push it's pretty much a jack rabbit start every time from stop, it's almost undrivable, any suggestions on what I could do?thanks for help, I've tried both Holley's tech lines for close to 2 hours with no answer! By going into the IAC settings and turning off the Idle Spark control and setting Target Idle to 750 RPM my idle issues are gone, and it now returns to desired idle after cruise. So I have been driving it for about 400 miles now to numerous car shows and going out for cruises around town, trying to work some of the bugs out from everything we did this winter, but I notice when I take off from a stop sign or I cruise at a very low speed (say30 mph) it seems to be very boggy from no throttle to about 1/8th throttle. The car would idle, I could hit the gas rev the car up and it ran great I also noticed two nice black spots on my garage floor from the exhaust. I received from the controller manufacturer greatly understates (at best) the repeated failures of others I know personally who have tried and failed. I don't want to go on too long here but once you know if you're trying to add or remove fuel, there are a couple of ways to go. Add To Cart. THANK YOU for the "First--Check Your Idle Speed Curve Setting!" That's not the IAC Hold Position, it's a percentage value. (Don't drive and watch--get a helper!) Once you've done this, the next natural step is to transfer the learn table to the base map, then go in and smooth out the sharp edges, which are going to be at these transitional states. If you haven't confirmed that they it is worth checking. To get it to idle the tps is at 2-3-4% even with linkage disconnected and a return spring installed. If you hit the gas it pops & backfires through the throttle body. You just need to go back through the IAC adjustment procedure now that idle timing control is enabled. Reducing that a bit will help. 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. I straightened that out, got it running and that's where it goes downhill. At idle my IAC is 3-4, AFR around 13-14, TPS is 0, timing 15-17. Is there away to program the ecu to compensate for this at start up. If the TPS is even just 2%, the IAC will go to the hold position (normally 30%) and will not change until the TPS goes back below 2%.If you create a datalog you will be better able to confirm if something is not working correctly. The engine runs beautifully, with perfect idle at 650 RPM, but every now and then I hear the IAC give a sort of "snap" and the idle is at 1200 RPM. Why is this? If you haven't installed a There's a procedure there I can share with you if you'd like.. It wont fire up. 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! 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. Any help would b great. I have an entire article on choosing between Sniper and Terminator X throttle body solutions and while Sniper is still a sound choice for some applications, Terminator X (with transmission control) is hands-down the way to go for those who need that. Idle quality is great, RPM is good, sometimes IAC is now between 2 and 5 exactly where it should be. When the secondary throttle blades are centered in their bores and pivot freely, an additional return spring is not necessary. If you did not rotate the distributor to set the actual timing to 15 that might be the only issue. To start viewing messages, select the forum that you want to visit from the selection below. I think in some of the Wizards with the handheld it doesn't use 57.5 as the default. Hello, Chris, thanks for the help.I have not installed the software yet, and I'm having trouble with two cars. Featured Products Sniper EFI $7.07 - $2,457.95 470 Products View Parts author Staff Writer 1711 Posts An Article About Video tech Sniper EFI Videos Sniper EFI Tech Sniper EFI sniper Installation 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. Thanks for any help. such high fuel pressure. Note that Brazilian gasoline has 27% ethyl alcohol. Also, I was seriously rich at idleso rich it hurt your eyes. With the vehicle in neutral, adjust the idle screw until the IAC Position reads between 2 and 10%. My sniper is doing two thingsFirst issue, the idle is set at 800 and will idle fine, then There is a glitch in the system. And your understanding of how the throttle position affects idle is exactly correct. It's all part of the adventure! Sometimes an engine can produce enough vacuum to pull the secondaries open slightly. It won't take much! Give that a go and see if you don't make some progress! The AFR was pretty consistent around 13. Great work, expert! Very annoying ended up being simple my rear plates would stay open constantly it was driving me nuts I'd let off the pedal idle at 1300 blip the throttle a few times finally come back to 850. This will let you know at a glance if something is going awry with the fuel pump. If I read it correctly, the solution from the other thread seemed to fix a constant 300 or so RPM increase. Could you provide me with some things to check or some things to adjust? Since the shield was put on, not a single problem, not one. The last pic is with the car in Drive. Mechanical Fuel Pressure Gauge on the inlet of your Sniper, now is the time. Holley Sniper IAC Surging???? Inj. 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. In your case, however, I think you're close to getting it running. I'm so glad you found this helpful--that makes my day!Don't get too concerned about the specific learn percentage. The broad consensus has been that the Sniper is an amazingly straight-forward install and starts and tunes as expected. I believe that you have this problem solved now with your new inline filter/regulator. https://www.youtube.com/watch?v=2JpHlS1ymBc, If this is your first visit, be sure to I'd suggest that you assume everything the previous owner did was wrong until you can prove that it was done correctly. 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. If you have a bellcrank in your throttle linkage, ensure that the linkage is not engaging the bellcrank at an angle greater than 45 degrees at either end of the throw. I will turn it up some. Thanks for any info./insight you can provide, Mark. Follow this link to download it for free if you have not already done so. Hello Chris. If the TPS reading on your Sniper EFI System does not reset to zero that is a problem that needs to be addressed. started up the engine. Interesting situation you have. I have been able to get it pretty It sounds like you need a bit more of a fuel squirt on acceleration, Brett. Otherwise, if removing the air cleaner eliminates the whistle then try to use a thicker gasket or try lightly greasing the gasket. At that point, with 90 PSI of fuel, the ECU can't turn the duty cycle down low enough to idle properly. My problem is low idle. The 5-6 times it has happened now have been after the car has been running for at least 20 minutes. I certainly appreciate your frustration (as well as your wife's!) You'll have to go back and forth a couple of times to get it just right. Price Point: $$, Robust, feature-rich multi-port EFI systems offer easy plug-and-play late-model V8 engine swaps. After this whole process, the car normally rotates without a very abrupt pedal. Note that sometimes you can get into a back-and-forth situation. Once you confirm the operation of your IAC then it's time to read my article on Solving RFI Problems. If it creates an issue (not normally the case) then you'll know. Hope this helps! Hey Tommy, we've got at least one thing in common. This may require shortening or lengthening a rod. What can I do? But nothing beats a good solid gut-check 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 did read some comments on regulator issues is there a way to check it for an issue ? Remember that as an EFI System Pro customer you have access to me at any time via my cell phone. And all too often we don't take that extra step of using a piston stop to ensure that the timing pointer is on zero when the engine is truly and exactly at top dead center. However I do have a couple of issues I hope you can help me resolve. 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. Resistance results in heat and heat results in more resistance. Do you have a PCV on the engine? But if you will just advance the timing at idle and see if it makes a difference then that will tell you what you need to know. I then saw you guys have an awesome little gauge that can hookup inline to the snipers existing fuel feed?? So check that timing and I think that you're going to find you need a good bit of advance. Adding a wrap to the return spring on the shaft is one alternative to solving this. Part# 538-13. 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. Were the additional load a simple step function it would be challenge enough for the ECU to gracefully increase the engine speed without overshooting. This will go a long way to improving your fuel map without manually adjusting the acceleration enrichment. Relatively new Sniper EFI install on a '69 Mustang 302. The idle will not return to the set value.The second issue is the same as the first but the motor will stall out. Ive played with the timing on this thing multiple times.Car was fullly restored last year. So if you are trying to achieve a stoichiometric mixture in ethanol (which is achieved at an AFR of 9.0:1) then you should continue to target 14.7:1 since that is what will be displayed. Those little 1/8 NPT gauges are pretty inexpensive and generally pretty easy to find locally.If you confirm that the pressure is indeed 90 PSI you could pull the fuel pressure regulator apart and check it. After much diagnosis, I ended up replacing the intake manifold gaskets. Lubricate the linkage so there isn't as much native resistance. I never had a problem with this. If there is an issue with using the Sniper EFI TPS signal, is there a remote TPS or an adaptor for the Sniper EFI that allows the TPS signal to be accessed for the transmission.