If I put the truck in neutral the TPMS will raise all the way up over 2000. the issue Due to when the pump i'm using now makes a loud howling noise when it gets ran for awhile and it gets at a 1/4 tank of fuel or less. Holley documentation and videos didn't work and the $300 I paid for "expert" tuning didn't work either. I'm also having a high idle problem but its different. But after sitting static idling for a little bit, the IAC goes to 100% & stays there. !I called Holley today, and before I could even described the symptoms the When I am coming to a stop, the rpms will hang at 1200-1500 rpms. When the idle speed screw is turned all the way out there should be just enough room between the bore and the blade to catch your fingernail. Sometimes an engine can produce enough vacuum to pull the secondaries open slightly. Any help would b great. Or alternator? If the ECU has not spent some significant time learning yet, I'd recommend going back through the setup wizard and getting everything back to default. It'll start & run till it's warm, then when I try setting the IAC every time, I try getting it between the 2 & 8% it quits. May God's grace bless you in the Lord Jesus Christ. Commanding the engine to automatically increase speed when switching into drive is a little scary to me though. If I read it correctly, the solution from the other thread seemed to fix a constant 300 or so RPM increase. Idle quality is great, RPM is good, sometimes IAC is now between 2 and 5 exactly where it should be. So, if pressing the throttle is making it start, it's because you're flooded.Which is consistent with your rich idle condition comment, right? When the system is up and running the fuel pressure regulator inside the Sniper is making a rattling sound like a shaking a paint can. On startup- cold or hot, I get a 2 second high idle of about 1500 RPM before normal set idle of 750 RPM happens. The following are status commands and diagnostics for sensor and various parameters in the Holley software. I installed the Holley Sniper in my Chevelle this winter with a brand new BluePrint 496. Cl. It sounds to me like it is way retarded.In the event that the timing is right then take a look at your AFR--the actual AFR, not the target. Copyright 2017 Cyberspace Automotive Performance, Inc. All Rights Reserved. I pulled over and turned the car off and then back on. I can tell you that when things aren't working the way you wanted them to work that nothing beats knowing for-sure that you don't have a fuel supply problem. Um, no. Doesn't want to start, runs like crap. And Earl's makes a fantastic little 100 PSI gauge. Turning off and then on again, the engine returns to normal. If this is the case then some adjustment of the linkage or the butterfly plates themselves is necessary. Price Point: $$, Robust, feature-rich multi-port EFI systems offer easy plug-and-play late-model V8 engine swaps. Hello. close to idle with the IAC between 2% & 12%. However, whenever you start changing things, you can get into a chain reaction. Holley Sniper EFI Troubleshooting Mudford Garage 8.6K subscribers 38K views 3 years ago My Bronco with Holley Sniper EFI was running poorly. Holley have given a new unit. The problem I believe this is creating is after I start vehicle (and its still in park), the IAC drops down to my hold percentage of 10% (since throttle % is not 0) before engine is warm and therefore causing the engine to stall out. After 50 on the throttle position I'm not sure if the whistle goes away or you just can't here it anymore. After pumping the pedal a few times at different times it dropped to zero and started to work. installing and cruising down the highway 70 mph I just wonder if all I have to do 63 bomb We are using Target AFR of 9.0: 1, Fuel Base approximately 40% higher. I am at the point where I almost insist that every Sniper EFI System owner purchase one of these. It has a lightweight centrifugal spring kit installed so I reach total timing around 2500 rpm. Honestly, I've never seen this happen but if the butterflies were misaligned on the shafts it could allow too much air to enter. The timing can drift 0-30 degrees just due to the width of the rotor tip. From herethe cycle continues and I am When this happens, it is impossible to convince the Sniper ECU to allow the RPM to drop below a set RPM--regardless of what the target idle speed setting is. The throttle position should be zero. The fix? Get a solid feeling for where it is when the engine is warm and the idle speed is correct. If not then you have some other issue that is behind this increased idle. Follow this link to download it for free if you have not already done so. Super helpful and knowledgeable. Can the return line be an issue?I have had 2 faulty gpa-4 255 walbro pumps go bad. Im thinking a faulty TPS. TPS% = 1 Thanks for any help. It could be a problem with the power/ground for the Sniper but much more commonly this is a result of too much RFI. If the IAC number is increased during this high idle, review the points about high idle from tuning issues. Then, the next time I cranked it, the idle went high and won't come down!" If you complete the process and find that the IAC is less than 2% at idle, repeat the process and use the set screw to make the RPM about 60 RPM below the target. Thanks again Chris, your help has been invaluable.If anyone is considering going EFI, Chris is the man to chat with. Also what would you say a desired idle should be for a 3 speed automatic ford? I then saw you guys have an awesome little gauge that can hookup inline to the snipers existing fuel feed?? Do I have to hook up sniper ac wire to relay or should iac pick up idle? Observing the temperature on the 3.5-inch handheld (only), wait for the temperature to achieve 160 degrees F. Once above 160 degrees, turn the idle speed screw so that the idle is about 50 RPM below your target idle speed set in step 1, above. Does anyone have photos of this additional return spring they installed? And thanks again for taking your time to answer these questions. 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. So you installed your Holley Sniper. I would suspect something is coming loose causing a stop to the EFI system/Fuel flow. Solution #1 Put car in gear take off and the engine runs GREAT, no issues drive for 10minutes take car out of gear and engine idles correctly IAC between 2 and 5 Solution #2 Shutoff engine wait 30 seconds, turn key wait for display to come up, start engine. This page was generated at 12:25 AM. We do that but most places don't. There are a few tell-tale signs that can help you diagnose the problem. It appears that I could now use the dongle and a laptop to custom tune for idle issues if needed. Physially manipulating the linkage by hand will generally reveal if you have a sticking linkage that is preventing the TPS from returning from zero. This was an issue in the earliest version of the Sniper firmware. A few, however, get tangled up getting the idle control working just the way they want. 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%. Holley EFI Electronic Fuel Pressure GaugeI think its a little ridiculous that I cant see fuel pressure on the display even though its measuring it but whatever. With the vehicle in neutral, adjust the idle screw until the IAC Position reads between 2 and 10%. In the warm state IAC adjusted to a position of 2 to 10%. While this video is not meant for the Sniper EFI user it does provide a great overview of how your ethanol tuning adjustments must be made not only to the base fuel map but to the other configuration settings. With an assistant pressing the accelerator, you need to make sure that when the accelerator is pressed to WOT that the throttle blades are fully opened, and when accelerator is lifted the linkage is fully at rest against the idle speed screw. Then, when you experience the high idle, note if the IAC number has increased. My IAC and TPS show zero when it does this. 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. The noise is definitely coming OUT of the throttle body. THANK YOU for the "First--Check Your Idle Speed Curve Setting!" )Take a look at your AFR during the starting process. If you are using your Sniper EFI System to control timing, navigate to Tuning > Advanced > Advanced Idle > Idle Spark and ensure that the Idle Spark Enabled is set to Disabled. Once you so this, and after you have your CAN-to-USB harness attached to your laptop with the Sniper software, you can see precisely the cells where the system is operating when the bog occurs. I have one customer who is having some similar issues and his AFR is down at 9.6:1 when it won't start. If your mixture is too rich, it means there's too much fuel and not enough air. You might even want to add our 4-foot extension harness that will allow you to connect/disconnect the display or CAN-to-USB adapter from inside the car (rather than trying to do that leaning over the engine and under the breather. Those don't impact the way the engine runs and can cause the whistle sound you describe. One of them might be faulty. Due to when the pump i'm using now makes a loud howling noise when it gets ran for awhile and it gets at a 1/4 tank of fuel or less. I'm thinking it could be the fuel pressure--- since I have a new Spectra EFI tank and there's been some reports of the interior coating coming off and gumming up the pump however the sniper display DOES NOT show fuel pressure.the Sniper DOES measure fuel pressure on its own - i've confirmed that with holley techs as they told me to purchase the fuel pressure gauge that can just hook up to the 1 wire gauge harness from the Sniper. Tps is saying 26% when it at idle. The window you saw in the image above pops up. You should get a light spray evenly distributed in all four barrels. I would gladly engage with you to solve this but ultimately you are going to need to go through whomever you purchased the system if a warranty return is in order. 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. 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.) If you go the other way then you might find that the IAC zero's out when the fans are off. The engine has 14: 1 compression ratio, we can not use gasoline. Save Share. I called support line he said he would have to look into it and call back. back upthe RPMs shoot up to anywhere between 1500 and 2000 and they will not get Covered the IAC port and set idle for 850 ish. We're having trouble with a Ford Maverick 302 V8, using ethanol. Seems like its too slow to grab idle when ac kicks on. I set it exactly like the instructions said and my iac is not only all over the place but when I finally did get it to the 2-10 range it's highlighted in red. In addition to avoiding this particular problem, the total solution is much better. I had that problem, right out of the box it would not power up, sent it back in, had defective hand held. I have not heard of this. You can adjust this number up or down but there is really no need to change it unless the car is stalling.The sucking sound is just what happens when the Sniper EFI System is paired with certain intake manifolds. One way is to very carefully watch the handheld monitor, and that may be adequate. This is normally used as an A/C idle-up circuit. There is a chance that the IAC is open but displaying 0% so start by putting your finger over the IAC opening. I did notice that when I thought I had it set I'm going to jump out on a limb here and say you either don't have adequate fuel flow or pressure. I know this is old, but I bought and installed a Sniper kit in 9/18. With select intake manifolds, the distributor housing and IAC valve on the back of the Sniper EFI throttle body are fighting for the same . Fortunately, I have an article that goes into this in some detail. Throttle Tip-In puts you in a part of the fuel map where you stay for only milliseconds at a time. There is no sense proceeding until your TPS is at zero at key-on. :-). But I think it is safe to say that you are now at a point were some manual tuning is a good idea. That, I am afraid, is going to involve a little bit of luck if you don't want to create a 250 MB data log. (It should be at or near 60 PSI at idle. The team at Holley has designed the perfect solution for your problems. No matter what do, my idle will not drop below 1350-1400 RPM when the engine warms. With the engine still idling high park, set the brake, open the hood, and remove the air cleaner.