S40 ignition only on a turbo bug - oscilloscope problems

This section is dedicated to discussion of DTA engine control units such as the DTA E48 EXP, P8 Pro, DTA S40, S60, S80, and S100, as well as all things ECU related.
bazibbo
Posts: 63
Joined: Sun Nov 06, 2011 1:04 pm
ECU Model: S40 Pro
Location: East Yorkshire

S40 ignition only on a turbo bug - oscilloscope problems

Post by bazibbo »

Hi guys

I'm just putting an S40 ignition only ECU on my vw beetle turbo, mainly as a way of controlling boost but also as an introduction to ECUs. I'm an absolute newbie and was hopeing for a bolt on solution, but I've run into problems.

Running the oscilloscope, I'm getting a result 'unknown Crank Wheel or one Already in the flywheel mode list' the image appears to be missing a few bars...

Image


I think the trigger wheel and sensor are mounted ok, it's from VW Speedshop
Image

and here's the engine, for interest other than anyother thing, it's now all wired and ready to go...
Image


any ideas?

ta
Barrie
Roverdose
Posts: 318
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ECU Model: S80 Pro
Distributor: Roverdose
Location: Stevenage
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Re: S40 ignition only on a turbo bug - oscilloscope problems

Post by Roverdose »

whats the size of the gap from sensor to trigger wheel? looks big from that pic.

Drew
lumley32
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Joined: Mon May 10, 2010 5:09 pm
ECU Model: S80 Pro
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Re: S40 ignition only on a turbo bug - oscilloscope problems

Post by lumley32 »

try takeing the plugs out, the dips and peeks are caused by the crank slowing down as it hits compression, sometimes this can cause problems

nice looking setup! even if it has to many wheels! :lol:
stevieturbo
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Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: S40 ignition only on a turbo bug - oscilloscope problems

Post by stevieturbo »

Start with basics to allow people to help.

What is the makeup of that disc ? ( I'll assume steel ) and how many teeth, and missing teeth ?

And what have you the ecu set to recognise ?

Sensor ? Hall or magnetic, and how is it wired ?

And when the engine is turning, is it turning fast and smoothly or very slowly ? ie battery and starter need to be good.
Jon K
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Joined: Fri Dec 04, 2009 1:45 am
ECU Model: S80 Pro
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Re: S40 ignition only on a turbo bug - oscilloscope problems

Post by Jon K »

If I were to start - I would look at the angle on that sensor. I don't like that its pointing at a 45. Get is square to the teeth - looks like a 36-1?
1992 700RWHP Pump Gas BMW
Image
Basil
Posts: 36
Joined: Fri Sep 16, 2011 2:28 pm

Re: S40 ignition only on a turbo bug - oscilloscope problems

Post by Basil »

The sensor needs to be perpendicular to the teeth, and that bracket looks flimsy. I see quite a few engines with odd triggering issues where a self made bracket is not rigid enough. You DO NOT want the pickup vibrating independently of the engine. Here's what i made for my Skyline RB26DETT engine when I put an external crank and cam trigger set up on it.

Image

Image

Cam Trigger:

http://www.gatesgarth.com/camsensor/camsensor.html


No trigger glitches at up to 8900 RPM.
bazibbo
Posts: 63
Joined: Sun Nov 06, 2011 1:04 pm
ECU Model: S40 Pro
Location: East Yorkshire

Re: S40 ignition only on a turbo bug - oscilloscope problems

Post by bazibbo »

Wow, you lot are on the ball!

Here's a few answers.

Gap's around 0.015, the wheel is fairly small, only about 100mm wide so.

Too many wheels? well it was a buell two years ago, but the family started to complain.

The engine turns over very slowly and not particularly smoothly, even on a fully charged battery. It's all brand spanking new, never been run, new pistons, barrels and heavy duty valve springs are all slowing things down. I will definately try without the plugs in, which should speed things up a lot. I managed to break the oil feed line last night, so I'm a day or two away from spinning it up again.

The wheel is a 36-1 magnetic steel, the ecu comes as part of a complete kit with a basic ignition only map and I've been very wary of messing with anything until I learn a little about it...... I'm a bit mechanically challenged at best. I can't tell you much more about how it's wired other than offering a piccy, but the loom came complete. It fires a ford coilpack. I'll get some decent pics up

Kit explained a little more here...http://www.vwspeedshop.com/product.php? ... 264&page=1

The teeth are angled flat to the sensor, they've got a neat angle cut in them. That pic doesn't do it justice. The kit is pretty tried and tested in the vw world, so initially I'm hopeing that the glitch is something I've created, or the slow spinning engine has created. Not cheap either! so I'll firstly look at all other avenues before playing with brackets etc. I chose it mainly because it was just about the only truly 'bolt on' kit, I really don't want to play with megasquirt and I'm a tart for shiny things

I'll start with whipping the plugs out and try again, once I've sorted my oil line.

thanks guys, really appreciate yout help.
stevieturbo
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Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: S40 ignition only on a turbo bug - oscilloscope problems

Post by stevieturbo »

You may need the engine spinning faster.

You still havent stated if the map on the ecu is even set to recognise 36-1 ?

And if it's spinning so slowly, what is battery voltage like when cranking ?

also, 15 thou sounds very close, as they do look like fairly large teeth
Basil
Posts: 36
Joined: Fri Sep 16, 2011 2:28 pm

Re: S40 ignition only on a turbo bug - oscilloscope problems

Post by Basil »

One thing I have noticed is with the teeth and sensor obliquely mounted like that the sensor gap will vary as a function of crank end float, a peripherally mounted sensor on a "conventional" trigger wheel will not see the same clearance changes.
Jon K
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Joined: Fri Dec 04, 2009 1:45 am
ECU Model: S80 Pro
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Re: S40 ignition only on a turbo bug - oscilloscope problems

Post by Jon K »

Ah, yes, if you have any crank end play it will show its face when you use the clutch lol. That'd be interesting "I lose RPM whenever I put the clutch in..."

Also - are you able to upload the map to the forum so we can see that it's setup properly?
1992 700RWHP Pump Gas BMW
Image
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