Trigger error b230ft

[Riff]

Vems:
 Serial: 758
 Trigger: Vr
 
Car - Volvo 240
Engine:
 B230FT, 2,3 Litre 8 Valve

Trigger sensor is brand new and installed correctly at the flywheel with the original bracket for the  Volvo B230F/FT.
Old cable from 3 pin bosch connector to the ecu was a mesh/braided shield cable that had the shield grounded to the bulk head, at the same point where then cylinder head is grounded.
New cable from 2 pin bosch connector to the ecu is a double shielded cable with foil inner and mesh/braided shield on the outside of that. Grounded at the bulk head at the same point as the old one.
Both have pin one to vr input on vems, pin two to sensor ground and pin3 to shield. Little or no difference in those two trigger cables with regards to errors and noise.

The ecu is mounted at the stock location of the original ecu, on the right side of the foot well on the passenger side.

The ground point is the point where the screw is in the middle of the picture.

There is a braided earth cable from the cylinder head in the upper left corner, the shield for the trigger cable is grounded at that point.


Made a trigger log without filtering enabled:
http://mail.linuxportalen.net/public/vems/2401/v3.3_n000758-2014-01-24-17.56.45.triggerlog

And one with filtering enabled:
http://mail.linuxportalen.net/public/vems/2401/v3.3_n000758-2014-01-24-17.58.10-filtering-enabled.triggerlog

But as one can see, there are still trigger errors, so I need to be able to get a clean signal.
From what I can see from the logs from august, is that I have no errors when the car is running, so the noise is at cranking.

One of the logs from August, and I believe I started in second gear as I had some problems with the starter. I tried to crank it over at first.
http://mail.linuxportalen.net/public/vems/2401/v3.3_n000758-2013.08.05-15.02.42.vemslog

Thank you for reading.

Kurt

[Riff]

Got an advice from Mattias in another forum, to try a resistor between +5v and the trigger input.
So will try this later tonight or tomorrow

This is one of the things that I like about the vems community It's very helpful for a newbie like me

[peter_jensen]

Normally this car use a low ohm (180 ohm) vr sensor but vems do not like this sensor.
You can install a BMW sensor 900 ohm (PnP) and it will work nicely.
The symptoms we have seen is when its getting could the car is hard to start and a lot of trigger errors.

Peter   

[Riff]

And it fits in the stock mount on the volvo?

I will try the resistor to see if it helps, since I just bought a new sensor
But will keep in mind that bmw sensor if it's an easy install 

Kurt

[Riff]

So, I tried the 10k ohm resistor, but still get trigger errors

[fphil]

Can you scope the signal and the ground line?
My experience is that the Vems box is a little noisy by itself, mean while you amy get a small ddp somewhere. I would try to get a good ground for the shield, check the sensor ground and I shall not be too confident withe that ground screw you shown.
Anyway your best friend is a scope.

[Riff]

A scope is on my wishing list

But I will try to overhaul my starter to see if that helps, since it's only when cranking.
The 10k ohm resistor helped, much cleaner signal but not quite enough.

But as you say, a scope would be nice to have when trying to get this right

Kurt

[Riff]

Activated the software filter for the trigger and now it's stable and error free

But I will try without the software filter when I've overhauled the starter and see if it gets better

[Erikk]

I had a customer who dropped his triggerwheel on the ground. After that the sensor picked up extra pulses in between teeth just like yours.

I put a 5k resistor between Signal and Ground (pulldown) to lower the signal and the problem was solved.
Later on he grinded the wheel back in shape and everything was good.

[Riff]

Maybe I should try with a 5k resistor instead then I think I have one at 6k.

I have a 10k resistor between signal en +5v now.

[Erikk]

The lower the resistor value, the stronger Pullup/Pulldown.

Give it a try, by putting your 10k between signal and ground instead of 5v, if that doesnt fix it, try 5-6k.

If you attach too strong pulldown you wont get any triggerpulses at all.


I usually just stick the resistor between the signal and ground-pin in the vr-sensor connector and when you find a value that fixes the problem, you can solder it in place.

[Riff]

Will try that, since I'm going to make a fresh harness anyways. Too much that I'm not satisfied with.
Love this community.

Thank you very much Erikk Much appreciated.

Kurt