Earl's Mechanical Fuel Pressure GaugeI could use that for a quick troubleshooting for 1/3rd the cost of the Holley one. I did buy the Sniper from you guys and the service was fantastic. One of them might be faulty. I am having an idle issue (other than that is absolutely perfect). I have probably 200 - 300 miles on this engine and it has always done this. From herethe cycle continues and I am Simply go to those cells, tweak them up or down as required, and the ECU should now be able to learn its way around the bog. Not good.There isn't set solution here that works for all engines. IAC Testing Procedure for EFI Systems And since they really had an insanely-tight monetary and real estate budget in the Sniper EFI System, it is unlikely that the added something that wasn't absolutely necessary--and then forgot to use it..And you are spot on about the little Earl's gauge with optional -6 AN port. I think I figured some of my problems outI'll try to explain. But I can tell you that for most people who try this it introduces so much RFI onto the Sniper that it never works right. This question is really outside both the scope of what we try to discuss in the comments section as well as the overall subject of this article. 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. The latest was changing the power brake booster.Today I drove it to work and no issues at all. The broad consensus has been that the Sniper is an amazingly straight-forward install and starts and tunes as expected. If I block off the iac with tape , I can get it to somewhat idle, but its not consistent. By the way your site and your accessory products are nice. 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. Part# 538-13. The fuel pump is mounted under rocker panel as low as possible and far away from any heat. Worst case you'll have a spare on hand, and if the TPS is faulty you will have solved the mystery. Holley Sniper review - The good, the bad, and learn from my - StangNet That is what I really respect about Holley. No problems with either cold or hot starts. I followed the instructions and set the IAC to 2-9% when warm with idle at 850 RPM. You'll be amazed at how much of this just "goes away" when you drive it enough. I'm happy to walk you through what is required. And yes, monitoring the fuel pressure is the right answer. If you patiently adjust this over the course of days you will get it just right.Again, glad this is working for you and look forward to a good report in the future! Your comment doesn't imply any sort of problem that would make me give up on idle timing control. Fuel Flow lb / h = 12.1 I know its not flooded because I can pour a little gas in the throttle body and play with the accelerator and it will start and run fine. These are "transitional" cells, and you really have to make the effort to learn in these areas of the map. Next, reach down into the secondaries and push the butterflies closed. The RPM would increase for no reason. You might have a bad IAC, but you can also have a bad vacuum pod on the transmission. Pw. This page was generated at 12:25 AM. If the engine will after the 4 seconds that the IAC kick drops off then it's not really going to help.At any rate, it costs you nothing to advance the ignition and see if that doesn't improve the idle, right? But I am having troubles.When stepping on the accelerator slightly with idling, it will be 2000 RPM all the time. other things that might cause the idle to faulter, but this is a good start. A couple of those and you should feel it getting better. (Grease can sometimes do the same thing as a more permanent gasket sealer without making the removal of the air cleaner such a pain.). Ensure there isn't a vacuum leak causing the IAC Position to drop to 0%. You can disable the idle spark control at the locations below. Its on a big block Mopar with stock electronic ignition . All times are GMT-6. I think that your timing is too retarded. Cycle the ignition as instructed by the handheld and then navigate to the distributor setup screen. Sniper EFI offers superior throttle response and wide-open throttle power. mean that the IAC is causing it. Maybe give it a half-turn before you start it and then start and tweak. That's not the IAC Hold Position, it's a percentage value. Now I have most of the bugs worked out it runs fine on the highway and around town it's just the idle. I had that problem, right out of the box it would not power up, sent it back in, had defective hand held. Jun 12, 2021. If you have an installation or start-up issue that is nagging you then please use the comments section to reply and we will gladly provide more information that we hope will be useful to you. Drop the IAC parked position a bit at each temperature point and sort of back into the solution. You're going to have to clean up the wiring in your engine compartment, In particular, look for spark plug wires that might be running near your throttle position sensor. You mentioned going from 13.5 to 14.2 but you'd want to go in the other direction--maybe to 13.2. Hope this helps! Chris---I am contemplating replacing my Holley 750 on my new low vacuum 600 HP 496 with the Holley Sniper FI system. 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. shut truck off. I have turned ignition off turned screw in 2 turns and turned ignition back on and tps is at 1-2% not sure whats going on. You can drop it down and you will find it will behave more like you expect. MSD pro billet and 6AL box These problems will go away when you do that. If I try and get the 2-10% i get all the way up to 1200 rpm. After a stall the car will restart but will be in a high idle. Once you know that then you can work on those problems. I presume your idle speed table doesn't increase at 200 degrees? It's not necessary to drive it that way. I thought 12.0 was leaner at idle, but I figured out I was wrong.lol. I guess we can't have everything. This will let you know at a glance if something is going awry with the fuel pump. (I'm running from a fuel cell on the garage floor 10 feet away with lines in plain sight and do see fuel coming from the return at a decent flow. If you haven't confirmed that they it is worth checking. You have to remove all hoses in order to debug the problem. engine works beautiful, the car runs a lot, but suddenly, the engine does that. At that point, with 90 PSI of fuel, the ECU can't turn the duty cycle down low enough to idle properly. That 60% (which is configurable) is known as the Clear Flood TPS. Price Point: $$, EFI Systems based on Holley's world-class Dominator and HP ECU's. would correct it (as it has for a multitude of other drive-ability issues) but this one little glitch seems out of it's range. Once it commands that high idle I haven't found anything to return it to normal, other than shutting it down and restarting. The next time it happens is the perfect opportunity to find the problem. I believe because the TPS is not registering. I have adjusted many settings and eventually mess it up and go back to the original map. Now it registers zero and I have good idle but it will not register until it hits 60 and up. If I put the truck in park it comes down to idle. https://www.youtube.com/watch?v=2JpHlS1ymBc, If this is your first visit, be sure to When the lambda is 1.0, the displayed AFR is 14.7;1 REGARDLESS OF THE FUEL. If they are closed, check the primaries. Thank you. I didn't find your site until I was having trouble. 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! 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. Good luck! It might be necessary to insulate or re-route your fuel lines if this can't be solved any other way. When stopping, the brakes are unable to overcome the engine so I go to neutral just to stop fighting the engine. What is it supppse to be at idle and while driving under heavy acceleration? When I put it in park the idle RPM was 2100-2200 each time. Laptop Access (Plus they it just looks way cool in your engine compartment!) My primary reason for going EFI was drive-ability, (Startup and take off without waiting for the engine to warm up) and not have the occasional hesitation a carburetor has especially just barely opening the secondaries. I have double checked everythingincluding fuel pressureand have followed the directions to a T.I plan on trying your 10 step process as soon as I get a chance. EFI Troubleshooting EFIand and EFI Tuning Tips - In The Garage Media Copyright 2022 Holley Performance Products, Inc. All right reserved. and when I close the IAC's hole with his finger, the engine is normal.The data on the touch screen I see are:AFR, A / F = 35.6 Any suggestions would be appreciated. At any rate, once the setting was moved up, the RPM jumped right to the target RPM and was solved. I think you'll be all set! Learning to install these is great--you're about to embark on the next great adventure of advanced troubleshooting. When I finished the install on my C10, I set it as follows: 13.1 at idle, 14.2 at cruise, and 12.9 at WOT. Holley sniper, bogging/ losing power "NOW FIXED" Price Point: $$$. I have quadruple checked my wiring and am certain it's correct. Hello, Chris, thanks for the help.I have not installed the software yet, and I'm having trouble with two cars. Hello Chris. Its just at low speeds, not sure if its loading up or leaning out. Im thinking a faulty TPS. Please advise. It may take a few tries. Did you find this enlightening? You could install the Holley Dual-Sync Distributor and let the Sniper control your timing. It will need to see it again and again. Thanks, That is an strange situation. 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. So I had my Idle set up perfect, with idle timing control off and engine hot the IAC was right at 2-4%. Your mechanical advance will naturally change the timing a bit but it should be fairly close. If it is already adding fuel, it may be worth expanding this into the area where the tip-in is occuring (and where there is no learning occuring. That is likely just confusing the issue.Instead, choose whichever setup most resembles your camshaft and stick with that. TPS 0. So, clearly, the "No" answer is wrong. But nothing beats a good solid gut-check You've got it running and warmed up but now you need to set. Holley Sniper high RPM - IAC problem? The throttle blade adjustment is at 2-6% at hot idle, and with warm engine 185F. 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. Don't know if I should put this in a separate post. When you key on, you will hear three distinct sounds: The ECU initializing the IAC, the fuel pump priming, and the injectors firing their prime shot. You may have to register before you can post: click the register link above to proceed. mail today. Thanks again Chris, your help has been invaluable.If anyone is considering going EFI, Chris is the man to chat with. A few, however, get tangled up getting the idle control working just the way they want. If you do find you have RFI issues then I've written an article on solving RFI problems. In that case, and if you have an EGR valve, I might be suspicious of something going on there. Any suggestions? $107.95. They also recommended that their ground be spliced into the Sniper ground as close to the Sniper as possible. Installed sniper on 65 galaxie. 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. It could be that the air flow across the secondaries as they are opening is creating that whistle but that isn't commonly the case.Did you check for leaks around the gasket of the air cleaner? >I'm using russell hi pressure gas line to feed the gas up to the sniper and using the stock steel gas line that use to be the feed line for the carb to return the gas to the tank. You might have a bad O2 sensor, really bad exhaust leak or a problem with the ECU. Cracked casing from a side cover screw being installed crossed threaded. Data logs show no EMI/RFI. Holley Sniper How To Set The IAC (Idle Air Control) in 5 - YouTube The whole topic of using the Sniper TPS for transmission control is one deserving of it's own article but I'll try to summarize a bit here. An under-sized filter will allow part- throttle operation but fuel pressure will drop at WOT and run very lean - perhaps surge under power. Use the idle speed screw to set the idle at a comfortable warm-up speed. It is temperature dependent but 30 is commonly where you find it. Doesn't want to start, runs like crap. Given the circumstances I would say that it is either the IAC motor itself or RFI but you seem to have ruled both of those out. Changing the rpm curve and target rpm has no effect. View Holley Sniper EFI Self-Tuning Kit - Shiny Finish. Chris, If you go too low then it may stumble or even stall when coming off of throttle. Holley EFI 543-105 Idle Air Control Motor I followed the instructions and set the IAC to 2-9% when warm with idle at 850 RPM. After much diagnosis, I ended up replacing the intake manifold gaskets. As I said I didn't buy from you so you don't owe me anything. 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. The weather in Ct has finally improved and I have put about 60 miles on the car with the Sniper system. Can the return line be an issue?So far this sounds like an ideal setup.>I have had 2 faulty gpa-4 255 walbro pumps go bad. 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). It works instantly for him.If that fixes your problem then you have a starting place.