Crank signal dropping out while cranking

boostedmini · Post by **boostedmini** » Sun Mar 18, 2012 11:14 am

dropping crank angle signal
Hi Guys,

looking for some help.

not sure what i may have done here but my car was running fine and i fitted a new coolant temp gauge and re-routed the crank sensor wiring to clean up the wiring.

now the bugger will not start...

when i turn ignition on and start cranking the tacho starts jumping, so this tells me I hav
E a crank signal, then after a few engine evolutions right when it would normally start, the tacho stops jumping as if there is no signal from the crank sensor.

i have gone right over everything that i have touched i have touched and cannot find a fault.

is this a tipical scenario when the crank sensor has failed? I would have thought not, surely it would not give signal and then just stop, when I stop cranking wait for a few seconds then crank again tacho jumps and then stops.

all fuese and power and earth signals seem fine.

what have i done????????

thanks guys

Grant

toenee · Post by **toenee** » Sun Mar 18, 2012 8:42 pm

Hows you VR sensor, had a similar problem with mine.
Turned out to be it was 2 close to the trigger wheel, now set with a gap about eighth of a inch.

boostedmini · Post by **boostedmini** » Sun Mar 18, 2012 10:00 pm

Thanks for that, but i have not moved the sensor since it was running, i will see if if can get my hands on another sensor for testing with.

I have a feeling it has to be somthing i have done with moving my wiring around, just weird why i get a pulse and then it stops.

thanks

Grant

Post by **brentp** » Tue Mar 20, 2012 12:35 am

Hi Grant,

If it stopped working immediately after you finished your wire re-routing it's highly unlikely a sensor failure would coincide with the wire re-routing. I would definitely go over with a fine tooth comb.

You might want to check the sensor polarity- the sensor will only work wired in one direction.

You can also review the "Verifying signals" section of the installation guide, here:

http://www.autosportlabs.net/MJLJ_V4_ve ... ng_Signals

Let us know what you find out!

boostedmini · Post by **boostedmini** » Tue Mar 20, 2012 2:19 am

Thank you for the reply Brent.

I am sure polarity is ok and as mentioned when i start to crank i have signal, while still cranking and after a second or two signal is cutting out, i tried polarity just encase and i got no tacho pulse at all.

I will go over all signals again.

Thanks

Grant

Post by **brentp** » Tue Mar 20, 2012 6:22 am

Also check the gap between the crank sensor and trigger wheel; Another idea; put a meter on the 12v power supply going directly to the EDIS module and verify it's getting voltage while you're cranking.

Keep us posted! We will get it figured out one way or another!

boostedmini · Post by **boostedmini** » Thu Mar 29, 2012 8:53 pm

Once again thank you Brent.

seems the connector on the EDIS module is a little iffy and had some green corrosion in it, pulled the oins out and cleaned them up and all is ok.

the red locking tab is a little week so i will try and get another.

thanks again

Grant