Just thought I'd ask as there isn't a lot of info out there. Look over all of your vacuum lines and fittings. Im thinking a faulty TPS. Across the board, all of our customers say how impressed they were that it started and ran right out of the box just by following the simple installation instructions. If you find that adding 5-10 degrees of advance helps then it's time to do reconfirm TDC. My issue is that the TP% will not reset with key cycle and its idleing at 9% TP. 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. To be honest, you sound like an ideal candidate for Sniper ECU ignition timing control. Hi Chris , greetings from Down Under (AUS) Just a note on the hi fuel pressure issue . These problems will go away when you do that. carburetor setup, but it does blow when I can't jump on the highway like I use 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). IAC Calibration / Hanging rpms | Team Chevelle The biggest issue is these problems are intermittent meaning they do not occur all the time. Now that you've got your IAC set I'm going to recommend that you run your setup wizard again, which will reset the ECU to the default settings. 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. The Sniper resets the TPS to 0% each time that you key the system on. Some have suggested mis-setting sets the idle speed at 850 RPM but I suspect it is not a fixed number but rather a delta of about 300 RPM above the target. Do you have any clue? Have you checked your fuel filter and made sure it's not plugged?If both of these are okay you're going to have to find a way to monitor your fuel pressure while under load. I got it home, checked it all over, everything is hooked up correctly. Throttle Tip-In tuning can be a bit of a challenge but I'm confident you can get this resolved, Mike.Let me start by saying that unless you've really done a lot of driving on the system in some useful learning situations then I would set this issue aside and not even think about it. I asked him a million questions and waited a long time to save up before purchasing the system and I have asked a lot of questions throughout the installation process. You want to ensure that nothing is hung up in there.The only thing that I can think of that would cause the fuel pressure to spike when the motor starts is the increased fuel flow at the higher alternator voltage (jumping from 12.0 to 13.5 volts or so.) Idle was back to normal but iac was at 0. The fix? By the time I was near home, the idle in Park was 1050, IAC 0. Yes its at 95lbs, needless to say he promised a new regulator would be in the An under-sized filter will allow part- throttle operation but fuel pressure will drop at WOT and run very lean - perhaps surge under power. Technically it is a warranty-voiding maneuver so proceed at your own risk. Having a TPS that won't go lower than 9% will affect the acceleration enrichment correction, and could create a stumble at the first moment of throttle opening.Yes, the IAC can and will fluctuate depending on changing conditions. It sounds like you need a bit more of a fuel squirt on acceleration, Brett. Two things to keep in mind as you do that. After manually making the sensor go through the full range a few times, I reinstalled it and now my TP will read anywhere from 0% to 4% when I key on. Commanding the engine to automatically increase speed when switching into drive is a little scary to me though. Find a lower price anywhere and we'll beat it by 5%! That is the default "Clear Flood" TPS setting and turns all fuel off until the engine cranks. Hey Tommy, we've got at least one thing in common. Some advanced conceptsIf you have the Sniper Can-Bus to USB Adapter, you can connect your laptop, open the software to the learn table, and get a visual for where in the table you are experiencing the lean bog. IAC is good 0-5% most of the time. Turn the idle speed screw on the primaries in about 2-3 turns after it makes contact with the linkage and starts opening the primary throttle blades. How To Adjust Iac On Holley Sniper If the issue persists, you may need to replace the IAC. The IAC is hanging open and not really at 0. 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%. Okay, try my method. Though it started and ran good, it was dumping fuel and would not lean out to AFR set points. Ok, so there are a couple peculiar things going on here. Get that thing installed and you're going to know a whole lot more about what's going on. Chris, you have it set. It has gotten a little better after I drove it for three hours today.I want to save the Kik because if I get this working good then I would like to add A C and use the kick for it.Motor is Mopar 360 with mild cam and automatic. Hello, I am having a tps and idle issue. I would only play with this if you are finding that the other adjustments I suggested aren't working. Not to bandstand here but this is the point when where you bought your system is so important. When I turn the key on I can hear it prime, but I don't think im getting enough fuel. However, I have never found that to be the case. There is no real mystery here. 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. If the solutions suggested above are not working then you need to review my article on IAC Testing Procedures. Do I have to hook up sniper ac wire to relay or should iac pick up idle? It's hard to know what the previous owner did right versus wrong. datsun sniper efi Holley RetroBright This 1974 Datsun 620 Bulletside Cruises With The Help Of Sniper EFI Bradley Iger 01/13/2023 features Latest News sweepstakes 2023 Hemi Engine Sweepstakes Gen III Hemi Enter To Win Holley's 2023 Hemi Engine Sweepstakes For Your Chance To Win A 600+ Horsepower 392 Stroker! One of the most common symptoms of a Holley Sniper EFI problem is an air/fuel mixture that's too rich or too lean. All times are GMT-6. You advise would be greatly appreciated. However, whenever you start changing things, you can get into a chain reaction. (Do this while you are cranking.) Hang in there--you can do it. 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? One of them might be faulty. check, I guess after reading everyone saying how great the system is after When I see that your TPS is 1%, that tells me that you may have an RFI problem. It then idles up from 750 to 1100. Somehow air is entering the engine that was not entering the engine when you originally set the idle speed screw. If they are closed, check the primaries. applies here because it is so important to realize that just because the IAC Glad to hear that things are working well! Tps is saying 26% when it at idle. Short drives is fine then it'll You will have to do this until the TPS stays at 0% when the throttle is closed. Adding a wrap to the return spring on the shaft is one alternative to solving this. However, I can't think of a single one that was because of low vacuum. You should get a light spray evenly distributed in all four barrels. All of the wiring exits below the rear fuel injector cover, for a completely stealth installation. Your mechanical advance will naturally change the timing a bit but it should be fairly close. If I go any more it will ping. 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. Idle quality is great, RPM is good, sometimes IAC is jumping around from 35 to 60. Idle quality is great, RPM is good, sometimes IAC is now between 2 and 5 exactly where it should be. This was an issue in the earliest version of the Sniper firmware. me know how it works for you. Is there away to lean the idle out? 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. Copyright 2022 Holley Performance Products, Inc. All right reserved. Your task will be to find that. If I block off the iac with tape , I can get it to somewhat idle, but its not consistent. I notice at 2-3% tps the iac is 18-25% and it stumbles, when the iac gets to my hold position of 30 it stops. You will need to change the -40 degree idle speed setting again but I recommend not touching anything else. Contact whomever sold you your system or Holley directly. And so glad you guys are enjoying the Sniper EFI system. Supports up to 650hp with Four 100 Lb/Hr Injectors! In some cases, you may only be able to put as little as 10 RPM between the hard idle and the target idle. The fact that it ran so (at times) with 90+ PSI fuel pressure is a testimony to the Holley's closed-loop technology. Idle Tuning is a very important part of tuning any EFI system, especially our self-learning units like Sniper or Terminator X EFI. Eventually the IAC will drop back to zero, I'll readjust it to 850 RPM & 2-9%, and then watch it steadily climb again. Fought a high idle issue until I changed your idle speed curve fix along with dropping the IAC hold to 10%. Give them a call and if they are unable to provide customer support the contact the Holley tech support line at 1-866-464-6553. I believe because the TPS is not registering. Since the shield was put on, not a single problem, not one. I.e. The resulting resistance can burn up fuel pumps, wiring and relays. There are two ways to address this--you can let the system learn or you can manually adjust the acceleration enrichment. Chris, I recently installed my Sniper and have an intermittent idle problem. The hold position is part of the response that keeps the car from dying when you come off the throttle. That's not the IAC Hold Position, it's a percentage value. Sorry I didn't buy from you but I didn't know you had sold them. it will jerk and rpm will go up and down and AFR will be around 20 : 1 or more or less. 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 Any idea's? The learn percentage should gradually decrease to virtually nothing as the map plus learn table begin to get more and more accurate to your specific setup. But there are several degrees of play there in which it should still work fine. It does this with the engine off. You can re-enable this after you have completed this idle speed adjustment process. Coming home from work today it was much warmer and took a little longer due to traffic. Holley documentation and videos didn't work and the $300 I paid for "expert" tuning didn't work either. Or ?I have put a fuel pressure gauge right at the inlet of the sniper and it is reading 60-64 psi.