GM LS1 RPM mismatch SOLVED

[Progrip]

Hi everybody. I have problem with rpm readings of 3gen LS1. The problem is that on starter and low idle readings are correct . But on high rpm is mismatch, for example the motor is running around 2k but the tacho reads around 3500 on 4k reads about 6000 rpm  . I have selected LS1 3-12 and 5-10, LT1 , multitooth  triggers and tried different filtering but there is no change . The car runs smooth afr is constant the only problem is the RPM readings . 

 

ecu: Link G4+ atom 4 cylinder wasted spark mode

crankshaft position sensor is connected with 5v Power supply .

Edited May 21, 2016 by Progrip

[Scott]

Hi Progrip,

When you say there is a mis-match do you mean between what the engine is actually running and what PCLink is reporting, or is the mismatch between what PCLink is reporting and your tacho gauge is showing?

[Progrip]

The engine is actualy running on lower rpm than ecu shows . For example engine running around 2K the ecu shows 3500 and aroun 3K hits the rev limit because the ecu thinks it is on 6000 . But the strange is that engine is running verry smooth . Now i tried to move from 5v to 8v supply to sensor but i have no readings . Now on 12v supply on sensor i have the same result . I`ve upgraded the firmware to 5.5.7 but nothing . On lower filtering i have bumps on rpm readings but on level 4 are correct only on the low RPM. Sorry about my bad english . Is there any special setting for this trigger its 24tooth with no missing i think? And is there any way to fire it with custom settings using multitooth ?

The rpm is measured by stroboscope . I have tested it on my bmw running on megasquirt wasted spark mode and reads correct . We have build another ls1 swap but with ms2+some signal converter and other engine revs up to 6300rpm and it sounds double  compared with this engine . 

 

 

Thank you 

Edited May 20, 2016 by Progrip

[Rich RDE]

Hi everybody. I have problem with rpm readings of 3gen LS1. The problem is that on starter and low idle readings are correct . But on high rpm is mismatch, for example the motor is running around 2k but the tacho reads around 3500 on 4k reads about 6000 rpm  . I have selectoed LS1 3-12 and 5-10, LT1 , multitooth  triggers and tried different filtering but there is no change . The car runs smooth afr is constant the only problem is the RPM readings . 

 

ecu: Link G4+ atom 4 cylinder wasted spark mode

crankshaft position sensor is connected with 5v Power supply .

You have a atom running a LS1? or did I read this wrong? Do you have the cam sensor hooked up? You might try multi 24 cam X1. Do you have the grey sensor for the crank? Obviously the 0-12v tach output is not sending the correct signal. 

[Progrip]

Problem solved . Thank you Rich RDE i hooked cam trigger with default ls1 settings +12v to cam and crank,  Trigger1 Chev LS1 3-12 Rpm filtering 4 and Trigger 2 settings Optical/Hall Level2 filtering triger 2 pullup ON and Trig2 edge rising .

 

 

Thank you verry much 

Edited May 21, 2016 by Progrip
solved

[Rich RDE]

Absolutely anytime! Glad I could help.