Crank Position Sensor Prblems

[Richie-Van-GTi 71 2 Cars]

can anyone help me please. Got a brand new crank sensor as the 2 others I had whilst giving resistance measurements consistent with auto data values only generate around 1.8 volts. Got the new one and sure enough its exactly the same. Im now concerned my problem is elsewhere on the car but struggling to find out where. Does anyone know what could the cause be? I was thinking spacing between sensor and flywheel but its not adjustable, its a be3 1.9 box and mi16 flywheel.

[welshpug 1,656]

the spaing isnt adjustable as you say, as long as its a 60-2 flywheel and a TDC sender hole theres nothing else you can do, except maybe check that the box is still secure to the engine?

[whizzer71 0]

Whats the actual problem with the car ?,is it a case that it just doesnt start,What engine / system do you have ??

 

[whizzer71 0]

Whats the actual problem with the car ?,is it a case that it just doesnt start,What engine / system do you have ??

 

[whizzer71 0]

Whats the actual problem with the car ?,is it a case that it just doesnt start,What engine / system do you have ??

 

[Richie-Van-GTi 71 2 Cars]

box is 100% secure, was one of the first things I checked. Im thinking maybe use guage to check distance from top of sensor mounting to flywheel tooth top and compare it against the sensor length then try to establish the gap created and the gap that should be there? But unsure if the gap will even effect the voltage? if its generating some voltage then surely it is registering the flywheel teeth and therefore within tolerance?

sorry about random ramblings but this is the only thing that is causing me issues right now and stands directly between my car starting or me throwing my toys out the pram and buying a complete 306 s16

[Richie-Van-GTi 71 2 Cars]

whizzer its an xu10j4r on bodies with megasquirt management. The megasquirt is not registering the engine cranking so wont spark or fuel. Using a known good start up map from an mi16 which is the same crank sensor etc. Also the ecu has been double tested for continuity across the circuitry and no errors have been found, everything else responds as it should also with the ecu. the loom has been double checked and shows only 0.6 ohm resistance cross it so this can also be ruled out.

[Guest larson]

can anyone help me please. Got a brand new crank sensor as the 2 others I had whilst giving resistance measurements consistent with auto data values only generate around 1.8 volts. Got the new one and sure enough its exactly the same. Im now concerned my problem is elsewhere on the car but struggling to find out where. Does anyone know what could the cause be? I was thinking spacing between sensor and flywheel but its not adjustable, its a be3 1.9 box and mi16 flywheel.

 

I was able to trigger VR input signal even with a screwdriver, waving it against CPS sensor (after fixing my MS board).

Even touching CPS with a screwdriver would show "Cranking" status in MegaTune.

I think it has nothing to do with spacing between flywheel and sensor as long as it is stock gearbox.

[Richie-Van-GTi 71 2 Cars]

cheers larson, if I touch a screw driver against the cps with a volt meter attached it does register as .1 volt so if that was enough to trigger your ms I wonder if mines a wiring issue leading up to the ms, maybe its not seeing a square wave? damn wish I had an oscilloscope right now.

Have asked you a question in engine mangament section

[Guest larson]

cheers larson, if I touch a screw driver against the cps with a volt meter attached it does register as .1 volt so if that was enough to trigger your ms I wonder if mines a wiring issue leading up to the ms, maybe its not seeing a square wave? damn wish I had an oscilloscope right now.

Have asked you a question in engine mangament section

 

Could you connect CPS to Megasquirt and look what MegaTune shows when touching CPS with a screwdriver?

Then you can be sure it is not wiring issue.

 

What looks strange to me in your msq file:

Basic Settings > Codebase and outputs function:

Yours (mine)

Trig Pos A = 7 (vs 10)

Trig return pos A = 19 (vs 18)

Trig pos B = 37 (vs 40)

Trig return pos B = 49 (vs 48)

 

 

Spark > Spark Settings:

Your Trigger Angle = 78 degrees (vs 60)

 

Cranking timing: Trigger return (vs Time based) it should be time based.

 

 

Don't know if my settings are wrong or yours or both

It should be specific to xu10j4r engine then? Ok.

 

What about adjusting trim pots on MS board? Have you tried that?

Edited August 10, 2007 by larson

[Richie-Van-GTi 71 2 Cars]

the trim pots are wound fully out as per instructions.

 

I tried the screwdriver trick with megatune but nothing changes, is there a screen somewhere that shows actual cranking as Im just going of the front screen that shows rpm. Ive now got my wiring exactly how you have yours, pin 2 to vr signal, pin 1 to vr - and pin 3 is not connected. Notice you mention shield? should the signal wire be shielded somehow?

Edited August 10, 2007 by Richie-Van-GTi

[welshpug 1,656]

box is 100% secure, was one of the first things I checked. Im thinking maybe use guage to check distance from top of sensor mounting to flywheel tooth top and compare it against the sensor length then try to establish the gap created and the gap that should be there? But unsure if the gap will even effect the voltage? if its generating some voltage then surely it is registering the flywheel teeth and therefore within tolerance?

sorry about random ramblings but this is the only thing that is causing me issues right now and stands directly between my car starting or me throwing my toys out the pram and buying a complete 306 s16

 

the gap wont matter, it either creates a pulse or doesnt. with the non-adjustable nature it means that all the BE TDC senders will be identical in this area.

 

 

 

oh, and on the S16, I know of one thats just come up for sale, but its in sourth lincs.

[Richie-Van-GTi 71 2 Cars]

I know of a slightly modded s16 just gone up for sale at £400 , as well as a 205 mi16 (no price) and a 405 mi16 lemans for £600 , too much temptation for my 205 to be messing me about like this.

[Guest larson]

the trim pots are wound fully out as per instructions.

 

I tried the screwdriver trick with megatune but nothing changes, is there a screen somewhere that shows actual cranking as Im just going of the front screen that shows rpm. Ive now got my wiring exactly how you have yours, pin 2 to vr signal, pin 1 to vr - and pin 3 is not connected. Notice you mention shield? should the signal wire be shielded somehow?

 

 

Tuning > Realtime Display

 

Runtime status bar on the bottom of this screen:

Status "CRANKING" should be highlighted in red when touching with screwdriver. At least it used to act like that when I tried.. can not guarantee though, sorry.

[madspikes 41 1 Cars]

I hate to state the obvious, but have buzzed the connections from the sensor to MS? And have checked that you have the right settings on the MS software?

 

I'd guess that if you put a multimeter between ground and either signal wire you shoud get a pulse votage on cranking, better with a scope.

 

Are you using shielded cable and have you grounded one of the ends of the shield?

 

Mad.

[Richie-Van-GTi 71 2 Cars]

I have checked the wires between sensor and ms yes, they are fine, one end of the shield is grounded at ms end, pin 3 is left un attached and yes there is a voltage on cranking but only around 1.9 volts. Autodata reckons it should be between 4 and 8 volts but Ive tried 3 sensors now all with same results. one is brand new, one is known good, the other is unknown.

[madspikes 41 1 Cars]

Did I read you were testing this with a multimeter? If so the pulsed voltage displayed won't be peak voltage more average, over a short period of time depending on the quality and speed of the meter. And i'm only guess but 1.8v would sound about the right ball park.

 

I tested my ECU and loom using a signal generator (0 to 5v squarewave) connected to the +ve sensor input.

 

Has the ECU been tested with the MS stim or such like, so to prove its not the ECU?

 

Do you get the same sensor reading from each end of the cable? Eg, right at the sensor end and right and the ECU end? Voltage drop in cable / noise - grasping at straws.

 

I take it that megatune is displaying the air temp and coolent temps ok, so the ECU is running ok? I've had a few funnines odd versions of code and not flashing the chip correctly.

[Richie-Van-GTi 71 2 Cars]

yes its displaying all the temp values ok and reads tps etc, I have checked both ends of the loom and get sam voltage both ends. the board wasnt tested on a stim as I didnt get one, starting to regret that now and it wont test now anyway I dont think as it has msextra code installed which the stim wont do a 60-2 IIRC.

[madspikes 41 1 Cars]

I believe you can use the stim the extra code and a 60-2 sensor. Within the options for megatune there are some 'stim wheel' setting which allow you to simulate a trigger wheel just using a square wave input, eg from the stim or a signal generator.

 

I'm not at home for a few days so cant prove this on my system.

 

Mad.

[Richie-Van-GTi 71 2 Cars]

not important anyway as I dont have a stim. Think I may just give up with it and go back to feckin carbs. so much simpler.

[Richie-Van-GTi 71 2 Cars]

hahahahahahahahahaha.

I have crank registering. it needed jumper swapping from vroutinv to vrout.

[Guest larson]

hahahahahahahahahaha.

I have crank registering. it needed jumper swapping from vroutinv to vrout.

 

unbelievable

even if it's the right way for VR sensor.

 

... ... ... have no words

 

ok, I'm glad to hear you are moving forward

Edited August 11, 2007 by larson

[madspikes 41 1 Cars]

Good news!

 

Mad