* There's an updated version of "Crank & Cam Sensor Setup" in the Holley EFI software. On the top Toolbar, click "Help" & "Contents". It's listed in the Help topics. *
This is the difference between "Digital Falling" and "Digital Rising". Digital Falling is much preferred:
I've datalogged the difference on the same Hall-Effect sensor, and Digital Rising had RPM errors.
Originally Posted by Danny Cabral If your crank or cam sync unit isn't transmitting a signal, troubleshoot the sensors, wiring, reference voltage & ground, reluctor, alignment, air gap (LINK), radial run-out problems (LINK), etc. If a regular datalog indicates an "RPM Error" when scrolling through the problem area, then it's time for a System Log to confirm which sensor flatlines. FYI: Crank & Cam A/D means Analog To Digital. It's not the +5V reference supply voltage. Troubleshooting 3-wire Hall-Effect sensors: https://www.team-bhp.com/forum/attac...e-beatbook.pdf (Fluke Multimeter Testing - "Hall-Effect Sensors", Page 17) https://www.yumpu.com/en/document/read/ (Understanding/Troubleshooting Hall-Effect Sensors - "Troubleshooting", Page 2) Record a System Log to verify crank & cam sensor signals. Check mark the "RPM", "Crank" & "Cam" channels. Look for a uniform, uninterrupted crank or cam sensor signal pattern. The crank or cam sensor signal should never flatline (no pulse) or indicate an RPM "Error" anywhere. Also, fully charge the battery and ensure the engine is cranking fast enough, at least 100+ RPM. Another common issue, is trying to analyze a compressed view of a long System Log. Zoom In for detail - click & hold at one point of the datalog, and drag & release to another point nearby. It's best to record short System Logs/Datalogs that capture the problem. http://forums.holley.com/showthread....s-amp-Datalogs (Datalog & System Log Information) |
Originally posted by Holley "Help" Contents
![]() This information above, is also found in the Holley EFI software; click on "Help", "Contents" & "Crank & Cam Sensor Setup". http://documents.holley.com/techlibr...10555rev17.pdf (Holley EFI Wiring Manual) http://forums.holley.com/showthread....=7592#post7592 (Datalog & System Log Information) http://documents.holley.com/techlibr...__statuses.pdf (Sensor Diagnostics & Statuses) http://documents.holley.com/crank-camsensorreq.pdf (Crank & Cam Sensor Requirements) http://i1206.photobucket.com/albums/...re/CamSync.jpg (Pictorial diagram of a 4x crank trigger and 1x cam sync.) http://www.yellowbullet.com/forum/sh...0#post26386690 (Incorrect Digital Falling Signals - 4x Crank & 1x Cam) https://www.youtube.com/watch?v=2u5B8BaRRXY (Devin Vanderhoof - MSD 4x Crank Trigger & MSD 1x Cam Sync Setup) http://documents.holley.com/199r10898.pdf (Holley EFI 36-1 Crank Trigger Kit Instructions) http://documents.holley.com/199r10562.pdf (Holley EFI 60-2 Crank Trigger Kit Instructions) http://forums.holley.com/showthread....ons-Holley-EFI (FAST Dual Sync Distributor Wiring & Setup Instructions) http://forums.holley.com/showthread....nition-Harness (Cadillac Northstar Ignition/Coil Pack Wiring) http://forums.holley.com/showthread....7990#post47990 (Wiring Modification To Pin B20, "EST +12V Output") |
![]() The following information is only if you decide to put timing marks on the damper (#1 cylinder TDC identification & 30° example): If necessary, use a spark plug hole type piston stop & degree wheel to first establish TDC, then make a damper mark at 30°. FYI: This procedure can also be used to correctly install/position a crank trigger kit/cam sync unit at 60°, 180°, 195°, etc. (Link). If using spark plug type piston stop, some people remove rocker arms from # 1 cylinder to avoid the risk of valves contacting tool. Also, remove all spark plugs for easy turning force (no compression) to prevent damage from harsh piston-to-tool contact. There's nothing wrong with installing a timing tape. Just ensure it's the correct one for your diameter damper. You don't necessarily need a timing tape, because both timing synchronizations can be performed with one timing mark. Multiply the damper diameter by 3.14159 (Pi), then divide by 360°. The answer is the distance in inches for one degree. For a 30° timing mark, multiply this value by 30. Cut out this distance on a strip of paper to avoid a straight line measurement. |
![]() New Magnetic Crank & Cam Sensor Parameters: There are new crank & cam sensor parameters for Magnetic type pickups in software version 2.2.0.3 & later. These only have an effect on ECUs marked with "Rev J" on the back. These only have an effect on ECU’s that with an ID# above 6000 on the label on the back. These parameters have no effect on older ECUs, which can be identified by not having a Revision level on their labels. If you have an older ECU, enter a value other than 0.00 volts, so the warning message stops appearing. The new variables are found in the System Parameters ICF: "Ignition Parameters", "Ignition Type", "Custom", "Configure". If the Crank Sensor - "Sensor Type" = Magnetic, or the Cam Sensor - "Sensor Type" = Magnetic, the following new variables appear for either: • "Minimum Signal Voltage" - This parameter defines what the signal strength must be for the ECU to recognize it as valid for the crank, cam and IPU speed inputs. Anything below this threshold is considered background noise. This value can be set between 0 and 5V and the higher the setting, the more noise is rejected and the stronger the signal has to be before the ECU considers it valid. Practically speaking, the sensor's signal at the lowest speed (during cranking for instance) defines how high you can set this. Obviously, if you only have voltage level of 0.5V during cranking, you do not want to set it to 1V because the actual signal will be ignored. It is advised to start with a value of .35 Volts. If there is a problem picking up a signal during cranking, lower this value .05 Volts at a time until you get reliable triggering during cranking (valid engine speed), then multiply this value by 0.75. If there is a problem with noise causing false pulses, you can try increasing this value. This parameter can also be found in the "Input/Output ICF", as well when the Input Type is set to "IPU Speed". Follow the information above to select this value. • "Filtering" - This is a variable that controls the new hardware based filtering used to help throw out short duration noise on the crank and cam inputs. A value of 1 represents the minimum filtering and 16 is the maximum filtering. Practically speaking, the sensors maximum frequency in combination with its strength determines how high you can set this. A 60-2 or 36-1 pattern generates a high frequency signal and you would almost never need anything greater than 8, and anything over 4 should be used with caution. For single pulse per fire crank signals and cam signals, the frequency is lower and you an get away with more filtering. If you use a filtering value that is too high, valid pulses can be filtered out at high engine speeds causing sync errors. You do not have to be under load to test for this. You might notice as you increase the crank filtering levels, you will have to increase the Inductive Delay values to keep timing from retarding at high speeds, since by its nature the filtering introduces a slight delay (Link - page 2). |
I've datalogged the difference on the same Hall-Effect sensor, and Digital Rising had RPM errors.

![]() Just some reference notes pertaining to crank trigger adjustments: The crank sensor sliding bracket, now does the task that turning the distributor once did. With a crank trigger, turning the distributor only adjusts rotor phasing. MSD has a good video on why rotor phasing is important: http://www.youtube.com/watch?v=aWMlNwGW0tM (MSD Tech - Rotor Phasing Video) http://documents.msdperformance.com/8644_tb.pdf (MSD Rotor Phasing Document) |

Excerpt from Holley EFI manual: NOTE - It is not advised to use a magnetic pickup distributor to directly feed the magnetic trigger input of the ECU. If the magnetic pickup distributor is connected to the ECU via the inductive pickup trigger wires, the pickup/rotor/cap phasing must be corrected. This operation may require a phaseable cap or rotor or possibly machining to the distributor and is therefore beyond the scope of most users. Even with the phasing corrected, the electrical noise inside the cap (due to the high voltage cap & rotor terminals) may be strong enough to cause electrical noise interference. It is advised to use a crank trigger system or a computer-controlled distributor. |
![]() Ignition Timing Cylinder Sequence Verification Ensure the Firing Order is entered correctly in Ignition Parameters (System ICF). Before the initial start, disconnect the fuel injector harness and verify at least, the first four cylinders in the firing order using a timing light. If your cylinders are firing in 90° intervals BUT in the wrong sequence, the coil harness is connected wrong (at the ECU or at the coil packs). Hopefully you have a fully degreed balancer or at least markings every 90°: 1st cylinder, in firing order, should fire at 0° (or 15° - add whatever your cranking timing is) 2nd cylinder, in firing order, should fire at 270° (or 285° - cranking timing added) 3rd cylinder, in firing order, should fire at 180° (or 195° - cranking timing added) 4th cylinder, in firing order, should fire at 90° (or 105° - cranking timing added) 5th cylinder, in firing order, should fire at 0° (or 15° - cranking timing added) 6th cylinder, in firing order, should fire at 270° (or 285° - cranking timing added) 7th cylinder, in firing order, should fire at 180° (or 195° - cranking timing added) 8th cylinder, in firing order, should fire at 90° (or 105° - cranking timing added) |
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