Clewett XDi issues!

[911hillclimber]

Hello everyone who may read this.
I have bought a Clewett/ electromotive XDi for my competition car fitted with a fresh twin plug 3.2 flat 6.
After 40+ hours it will not produce any spark.
I have had a very long run with both companies and they have just tested the XDi unit with VR sensor, and say it is trouble free.

The XDi light goes to solid Green when switched on, remains so while engine cranking, drops to solid red when you stop.
The manual says the sensor is at fault. The sensor gives 4 volts and 620 ohms and a perfect sinusoidal wave form.

I am at my wits end with both companies and getting nowhere except being asked for more money.
I live in England, makes things far harder.

Can anyone on here shed any light on this please with positive suggestions?

This is the car:

[Fredie]

Did you open the back of the box and check that the dip switches were in the right place for your application?
If memory serves me right, Electromotive sends them out for an application OTHER than a 6 cylinder twin spark.
Regards
Steve

[stownsen914]

To be clear, the 40+ hours that you reference ... that's a reference to the XDi running previously on your car?

Separately - once you get this issue sorted, more pics and info about the car please!

[Fredie]

I may have jumped the gun here in an effort to help you.
I just installed one of these on a friends 930 twin plug, so some of the info is still fresh in my mind.
I guess we need more specifics as to what the timeline of 40+ hours means. Etc…
Cool car! Love to learn more about that build and chassis.

[s5uewf]

There is also a pretty extensive forum for Electromotive ECU's and tuning:

https://www.tapatalk.com/groups/electromotivetec/

I find answers there but using the search function helps there.
Also, I have called Electromotive directly before to ask a question, and they referred me to the forum, as they participate in it (or did when I was actively looking for info).

[jjeffries]

Here’s 911hillclimber’s build thread for his engine, which also shows the race car.

He also has a long hood 911 (with a Webasto-style fabric sunroof) and rebuilds old Honda small twin ‘bikes … a good bloke!

https://www.ddk-online.com/phpBB2/viewtopic.php?f=28&t=69167

DDK-online is a superb forum, BTW.

John

[911hillclimber]

Hello everyone, and specially to John!
To give some details:
Bought the XDi new a few months ago for this engine. Came from Clewett, a kit for a twin spark 911, 3.2.
Spent 40 hours installing it in the frame of this car and tried to start the engine. No spark, just a solid Green light on the XDi including when cranking the engine. When I stopped trying to start it, the light goes solid red.
Had many many emails to Clewett who gave a lot of answers and suggestions, None worked.

The conclusion was the XDi had to go to Electromotive at my cost. I am in England.

The unit was tested by Electromotive and stated to be "trouble-free".
It was suggested I buy a Hall crank sensor for $149 plus shipping and customs duty.
I also have to pay to have the XDi returned to me.
This action will cost about $500 on top of the purchase cost of $2000.

Electromotive also wished me to have a nice day.....condescending in my mind.

I have still nothing to start this expensive twin plug head engine. I have started it carefully using a simple distributor and coil and it runs great.

The point of this thread on Pelican is to reach out to anyone with XDi experience who can shed light on this failure to work.
The Clewett system is very rare in the UK, I know to 3 only.

I have 2 options:
1
To pay again for parts that (might) work and to get the XDi I paid for back to me, about $500.
2
To tell Clewett and Electromotive to forget it, bite a bullet and replace the XDi with a UK motorsport ECU from DTA 1 hour drive from me, and interface the Clewett peripherals to the ecu.
Cost is £1200, about $1700

I await the response (if I get one) from Stephanie, General Manager of Electromotive I hope over the next few days.

This is a very short precis of the situation I assure you.
Here is the engine right now:

[r lane]

Years ago, 15-17, I installed an Electromotive fuel and ignition system in my 92 turbo. Would not work, did the hoop jumping exercise for a while to no avail. Sent the ecu to Electromotive for bench test and it tested good. Reinstalled and more hoop jumping. Finally he said, send me your ecu unit, as I have that same piece in one of my cars and I will test it there. Failed in his car as well. I recieved a new unit from Electromotive. If you could find a way to test it in that manner, as I was fortunate. I have been burned more than once with bench test info. Should the light not be blinking as you crank the car

[911hillclimber]

My XDi box literally leaves them today for England with a new hall sensor.
They took $16 off the price.
Costing a total of 384 dollars to get the lot back here....

I do hope it works.
If not I will accuse them of a product unfit for the application.
I will then have to buy another ecu to replace it.
Another $1000, and so it all goes on.
The green solid light should blink green/red while cranking.
Failure to do so means signal from crank sensor has not been found by the XDi unit.
It has never ever blinked...

Should be with me about end of next week.

I hope to be surprised!

[Focker]

Have you checked the dip switches that they are set for twin plug? Although you purchased a twin plug kit from Clewett, they likely did not open it up to set the dip switches.

[911hillclimber]

Indeed they supply the XDi unconfigured, but I have set it (and checked it many times).

I really have gone though the Manual, through all of Clewett's suggestions, Electromotive's too.
I've had 2 people with ignition deign experience visit the car and spend 5 hours going through the basics and experiments.
I have re-configured the whole layout of the system's components, I've examined the sensor's output, the XDi running on an independent 12.7 volt battery.

I sent it to Virginia for testing at Clewett's suggestion, checked out "trouble-free", $100 cost to me.

I have just paid a further $380 for the return of the unit with a new Hall sensor.

I have about $2100 in this and have never seen a spark.

Maybe it will spring into life when i get it back late next week? Not holding my breath....

This is a sketch in plan view of the car and the system layout and proximity to each other.

[wallra]

who made your wiring harness? I'm only asking because I got the elective
motive gt200 from clewett who made my harness and had no spark so when I looked at the harness I found the crank sensor plug to be wired wrong. harness side

[fred cook]

Once you get the ECU back in the car, try cranking the engine while looking at the tach. It should register 200-300 rpms (assuming an electric tach) while cranking if the crankshaft position sensor is reading correctly. If not, it will not start.... as you have discovered! What gap are you using for the crank sensor? You might need to move it closer to the sensor wheel. I have one of these systems powering my 3.3SS engine in my SC and it works as it should. Also, double check the wiring going to the control box and make sure you have them all connected correctly. Good luck!

By the way, great looking car!

[911hillclimber]

I appreciate all your replies, always helps.
The VR sensor has been set at 48 thou, 35 thou and 10 thou, no difference.

The signal is far sharper and greater amplitude at 10 thou, Clewett said it will not start so close, 40 is the best, so i positioned it there.
No difference.
I removed the plugs to remove the cylinder compression and raise the cranking speed...
No difference.
The looms are all as supplied by Clewett. I have found one crimped pin connection where the wire pulled straight out already.
Any connections i make are crimped and soldered.

While this XDi is on it's way back I'll go though EVERY wire again, security, position erc in prep for the Grand Day when it will simply start.

The Starter, a hot topic.
It is a little known Brize starter, high torque and very compact. All leads have iron clip-on suppressors.
I estimate a cranking speed of nearly 2 revs /second, but have no means to measure it.

[winders]

Originally Posted by 911hillclimber

Any connections i make are crimped and soldered.

Soldering a crimp is bad idea:

https://youtu.be/pOTrS6-mNtA

[wallra]

http://electromotive.com/wp-content/uploads/2017/04/XDI200-V01-Manual.pdf page 15 show's how the plug should be wired.

[3rd_gear_Ted]

Certain starter motors and certain ECU's don't like each other.
Big ass wire to the ECU source straight from battery.
Grounding of the sensor leads both ends of cable.

Get a Motec

[Porsche 935]

I have run these for 30 plus years. If the xdi unit is not changing colors during cranking then usually the crank sensor is bad. Have replace many over the years. I do not use the cam sensor but you could check that also. Always keep a spare sensor in the car just in case.

[911hillclimber]

We had an occilloscope on the vr crank sensor and has a good sinusoidal wave form, surprisingly clean, esp with the air gap of 10 thou.
That is too close, so back to 40 thou.
The XDi is coming back to me with the Electromotive hall sensor.
Should be better....

[Focker]

Although it sounds like you've done this already, I would double check the pinout of the harnesses as they connect to the xdi.

Eliminating the unknowns, electromotive says the box works. You tested the sensor to see that it works. The only thing left should be the wiring.