Loss of signal on crank sensor wont rev past 1500rpm?

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e30m10turbo
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Joined: Fri Apr 14, 2017 6:39 pm

Loss of signal on crank sensor wont rev past 1500rpm?

Post by e30m10turbo »

Evening all, ive finally managed to get my e30 to run and idle (somewhat) using the Ms1 V2.2 with a VR Daughterboard 029y4 firmware. Problems now is that my rpm signal seems to jump and spike around while idling.. Whenever i try to increase the throttle it seems to loose signal and hard cuts like a limiter, limiting me going past 2000rpm. I am using a Sheilded wire with the sheilding grounded at the megasquirt end with a ford VR sensor. I realise there is most likely too much noise/interference on the line so that is looses signal whenever rpm is increased.. but is there a way around the noise? ive heard of installing a resistor inline and such.. any info would be great! i have attached my msq, datalog and tooth log.
Matt Cramer
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Re: Loss of signal on crank sensor wont rev past 1500rpm?

Post by Matt Cramer »

Can you get a tooth log instead of a trigger log? The trigger log is "downstream" of the wheel decoding, while a tooth log will show the actual signal reaching the processor.
Matt Cramer -1966 Dodge Dart slant six running on MS3X
e30m10turbo
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Posts: 19
Joined: Fri Apr 14, 2017 6:39 pm

Re: Loss of signal on crank sensor wont rev past 1500rpm?

Post by e30m10turbo »

appologies i must have selected the wrong file - try these.
Matt Cramer
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Re: Loss of signal on crank sensor wont rev past 1500rpm?

Post by Matt Cramer »

The tooth log file doesn't seem to capture a loss of sync. Maybe you could run the tooth logger and regular data logger at the same time?
Matt Cramer -1966 Dodge Dart slant six running on MS3X
e30m10turbo
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Re: Loss of signal on crank sensor wont rev past 1500rpm?

Post by e30m10turbo »

Yeah sorry it was a bit rushed, I will take a datalog and tooth log at the same time doing what I think is loss of sync when I get home from work :) thanks.
slow_hemi6
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Re: Loss of signal on crank sensor wont rev past 1500rpm?

Post by slow_hemi6 »

MS1 won't show a loss of sync.
Find the Manuals up top under Quick links: Manuals. :RTFM:
Cheers Luke
e30m10turbo
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Re: Loss of signal on crank sensor wont rev past 1500rpm?

Post by e30m10turbo »

Ok well that doesn't help does it. I will post a datalog and tooth log anyways. Someone might have an idea why I can't get my car to rev.. no rpm = no tuning!
slow_hemi6
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Re: Loss of signal on crank sensor wont rev past 1500rpm?

Post by slow_hemi6 »

On page 14, I think it is, you can see the double length bar for the missing tooth and then around the 2nd peak compression bar there is a bar around 3 times the length of a normal bar. This is teeth not being counted and there fore showing up as one extra long bar.
Find the Manuals up top under Quick links: Manuals. :RTFM:
Cheers Luke
e30m10turbo
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Re: Loss of signal on crank sensor wont rev past 1500rpm?

Post by e30m10turbo »

So the cause of the sensor not counting teeth would be sensor not close enough to the wheel? Or what is your opinions.
slow_hemi6
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Re: Loss of signal on crank sensor wont rev past 1500rpm?

Post by slow_hemi6 »

Could be physical or could be the lm1815 configuration. What have you tried to solve the issue?
Find the Manuals up top under Quick links: Manuals. :RTFM:
Cheers Luke
e30m10turbo
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Re: Loss of signal on crank sensor wont rev past 1500rpm?

Post by e30m10turbo »

Haven't had time so far, will over the weekend. But I'm going to try resistor spark plugs, inline resistor moving the sensor closer to the teeth. It's annoying because if I crank the car over while cold if it doesn't start the first couple of turns it floods and then near impossible to start as I have to pull plugs to clean them. -.- really frustrating. Maybe it's dumping too much fuel in on a cold start
e30m10turbo
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Re: Loss of signal on crank sensor wont rev past 1500rpm?

Post by e30m10turbo »

alright people, so i changed my spark plugs with brand new ones. moved my sensor wiring away from anything electrical, made sure it was sheilded properly and the sheilding to be grounded at the MS end. car actually fired up straight away without hesitation and then idled the best it has so far. managed to get a datalog and tooth log of what is happening! finally! let me know what you guys think.
slow_hemi6
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Re: Loss of signal on crank sensor wont rev past 1500rpm?

Post by slow_hemi6 »

it is sometimes counting tooth 1 and 2 after the missing tooth as only one tooth.
Find the Manuals up top under Quick links: Manuals. :RTFM:
Cheers Luke
e30m10turbo
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Re: Loss of signal on crank sensor wont rev past 1500rpm?

Post by e30m10turbo »

yeah i noticed this aswell, any ideas on why?
slow_hemi6
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Re: Loss of signal on crank sensor wont rev past 1500rpm?

Post by slow_hemi6 »

slow_hemi6 wrote:Could be physical or could be the lm1815 configuration.
Find the Manuals up top under Quick links: Manuals. :RTFM:
Cheers Luke
e30m10turbo
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Posts: 19
Joined: Fri Apr 14, 2017 6:39 pm

Re: Loss of signal on crank sensor wont rev past 1500rpm?

Post by e30m10turbo »

Success! If anyone is having these problems, were solved by switching the polarity of the VR sensor wires and moving the sensor closer to a gap of 0.8-1mm. Thanks everyone!
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