Holley sniper efi keeps stalling. You need to check the actual fuel pressure.


  1. Holley sniper efi keeps stalling. But don’t worry – with the right knowledge, you can identify and fix most Holley Sniper EFI problems without breaking the bank. 0L. Maybe I have to keep adjusting the IAC and Decay, but I'm lost at this point. The issues were sporadic, which makes chasing it down difficult. I've been running the Sniper Stealth with a Holley in-tank returnless pump for two years without any problems. 0L headers on it. It's a manual transmission and when we engage the clutch or move the transmission to neutral and let the revs drop, more often than not it just stops running altogether. I'd appreciate any insight anyone can extract from the datalogs. We have, however, had some issues with the engine not running perfetly. Feb 27, 2021 · Using the Holley Sniper EFI software (LINK), look at where the live cursor moves to during this occurrence, and manually tune that area of the Base Fuel Table (enrich or lean) & Base Timing Table (optimize ignition timing). Oct 7, 2023 · Holley snipers have a internal regulator installed which is preset at 58. Nov 20, 2023 · Greetings! 1983 Mustang 5. That fixed the issue, was a bad cpu. Since it got cold (below 50°F), when I start my car every few weeks it runs for a few minutes then stalls out. Ever since day one I've been having hard starting issues when both hot & cold that I could use some advice on. No exhaust leaks, timing set properly, new HEI distributor, plugs Sep 19, 2022 · Not to start another thread, Holley recommends 12-920 for single Sniper EFI, which I bought, could it be that dual quad 2x4 needs a bigger pump? Usually fuel pump calculators care only about HP, BSFC and target pressure. My brother and I build the car together, and we have the BluePrint 347 with the Holley Sniper EFI in our Mk4 Roadster. One is leaving the throttle closed, the . After this starts, it also develops a problem idling, by surging and slowing until it stalls. So engine info: '67 Mustang with an '85 date code Ford 302. We have tried various combinations of idle parameters including reducing Ramp Edit ended up getting a hold of Holley, and after 2 months of “we’ll send you a new ‘x’ and we’ll send you a new ‘y’”, they finally ended up sending a replacement Sniper unit. May 11, 2025 · By following these steps, you can identify and resolve common starting issues with your Holley Sniper EFI. 540 BBC Hello all. The faster I come to a stop, the more likely I am to have this issue. Have to turn key off wait a few minutes and it'll restart. The engine is a 267 SBC mated to a 700R4. Although Holley employees will take part in answering questions from time to time, your questions may or may not be answered by Holley personnel. Jan 9, 2023 · Please be aware that this is a community forum. I've got it setup with a World-Class T5 and a Flowmaster exhaust. I'm having a hard time extrapolating useful information from the datalogs. Once warmed up it'll keep running. Snipers have a lot of trouble with the regulator and fuel system. Hey everyone, I’m pretty sure I’ve solved a couple of common problems with the Holley Sniper EFI system — especially issues that happen when things get hot under the hood. Ensuring your battery and starter motor are in good condition is crucial for reliable engine starts. I installed a basic Sniper setup complete with a baffled fuel tank and Walbro 255 LPH in-tank pump on my '74 Chevy half ton pickup. Thus, Holley can not guarantee an answer or timing on an answer. Oct 1, 2022 · Hoping to get some help as I'm cooked! I have a SBC 350 and when I come to a stop, or slow down and coast from time to time (say once a trip), the car will lose RPM and stall. Feb 25, 2019 · My engine stalls or idles down near stalling when coming to a stop sign or stop light. 5 psi. Jul 7, 2024 · Using the Holley Sniper EFI software (LINK), look at where the live cursor moves to during this occurrence, and manually tune that area of the Base Fuel Table (enrich or lean) & Base Timing Table (optimize ignition timing). This usually happens when I’m in neutral. Configured as follows standard bore hypereutectic pistons from Summit can provide part number if necessary. Hey guys, I've ran into a issue with our mustang (390 S-code, stock components afaik). I've never spent time analyzing engine information electronically before. You need to check the actual fuel pressure. Re-ringed cause it Feb 26, 2022 · Sniper EFI Tuning & TechThe issue I have is that the engine stalls out when bringing the car to a stop (for example) to a traffic stop sign. The symptoms include just generally running poorly at idle, but more so when hot, stalling at stop signs & May 1, 2020 · Ive been running a Holley Sniper for a about four years now. I was watching the handheld monitor screen when it happened once and the IAC % went up to 100% and a bunch of red warnings occurred, then it stalls. There's no time to start or take a datalog so I cannot capture one. It Jun 15, 2020 · Sniper EFI Tuning & TechI've attached datalogs of the event. Next thing I will be doing. Gradual slow downs in the neighborhood are rarely a problem, but coming off the highway is usually a problem. Any advise would be huge. . If I take a ten mile Feb 13, 2021 · Sniper EFI Tuning & TechHey everyone, a little backstory here. In the last year I have been struggling to fix a consistent hesitation I get under acceleration after it warms up. We have about 7,500 miles on the car. Dec 12, 2022 · Hey guys. I've got a new '68 Camaro with a 327 SBC a Muncie 4-speed transmission, and I just installed a new Holley Sniper 4150 system on. Very new to the Sniper EFI in general stuff. Brand new long tube headers, Edelbrock performer intake, otherwise pretty much stock. The car will startup, but only if I lightly press the gas pedal (otherwise Jun 18, 2023 · When the engine is warmed up, my Sniper will randomly start to run very rough and then stall within a second. The car is running a bone stock 302 with nothing more than an Edelbrock Performer intake and 1986 Ford 5. 006 file is trying to keep it running by feathering the pedal. May 27, 2025 · Are your morning drives being ruined by a temperamental Holley Sniper EFI system? Those mysterious stalls, frustrating no-starts, and check engine lights can turn your classic car experience into a nightmare. I have Jan 24, 2024 · Need help. Overall, we have thoroughly enjoyed the car. Having issues after installing: Sniper EFI, Sniper Hyperspark dizzy, Sniper ignition coil and box. Apologies in advance. E303 cam, GT-40 3 bar heads engine gone through 3000 miles ago. zhtt zvhrax g4izgz t3sud hzp1c z8 mqwbv ntp cgzwyr zr7i