MoTeC Global Forum

Hi,
Am having cold start problems with my Ford Duratec 3.7l V6 on M800 emu, it fires but does not catch and run. I did a Ref/Sync capture yesterday and the Crank signal is very noisy, attached, is that normal or a problem with the sensor or the wiring please ?

Appreciate your advice.

Ta
Dave

More or less impossible to tell anything from the screenshots. Posting the log file and the ecu config will increase the chances of someone being able to help. From the ref / sync capture screen you can save the capture as a file, that may help too.

Thanks Sean, log and ref sync capture attached. hopefully.

Ref sync capture looks tolerable to me, falling edge on both. The log file is the one with the .ld extension, not the .ldx

Cheers Sean, apologies for my error, ld file attached.

Of note I have fitted an aftermarket BBS throttle body, I have set Throttle Hi and Lo, 1 set, tho not 100% certain I've done that correctly, a sensor check seems to show its working as expected. It was a bugger to start from cold before, hot start was grand.

Ta
dave

Dave, what's the story with the battery? Is the battery failing, or is it just flat and the starter itself is failing? I'm seeing lowest of 6 volts when starting cranking, seems to be averaging somewhere in the 8 volt range. I'm surprised it even syncs with that low voltage.

I'm assuming from the log file that you were cranking with the UTC plugged in and ECU manager open? If this is the case, with battery voltage that low it's possible to corrupt the file in the ECU when cranking. Try saving the current file, then doing a file compare with a known good file to check if this is the case. Also, with ECU manager open the errors don't clear themselves, so that the errors logged don't necessarily match when the channel was in error. Press E in I2 to display the errors.

Obviously I'm not familiar with your setup, do you really have no MAP, MAF or BAP (barometric pressure) on the vehicle? None are defined in the ECU file, which seems strange(ish).

I'm seeing some weird steps in the injector pulse width whilst cranking , starts cranking at 24 ish then partway through cranking it drops to about 6.5. It almost looks like it's trying to start, then the RPM hits the 600 rpm run threshold and it chops the fuel pulse width. As yet I don't know why it's doing that.

Cheers

Hi Sean,
Yep the battery only seems up to about 6 attempts at starting, before cranking speed drops off. I dont think I had my jumper battery attached for the logged event, but will for the next post.

Yes, you are correct I had manager open and my utc connected for the log as I did that just after the ref sync capture.

I will repeat disconnected and manager closed.

I dont follow press E in I2, is that key E in the analysis software? I have been resetting error in the Manager diagnostic page, keeps coming back with Ref Sync errors, Noise A/r.

There should be a MAP or MAF, will check on the car - i just bought it last year and raced it in Sept, it was a bugger to start from cold then, hot start no problem.

What your saying about the fueling is similar to what i get when trying to start the car, it will fire and has run momentarily then stops, after 5 or 6 attempts the plugs are soaking wet. I did have the fuel rail off to clean and calibrate the injectors if its likely to be air in the rail, its supposed to self bleed ?

The car is a Ginetta G50 that has had a 2012 Mustang Duratec V6 grafted in, the engine is stock, apart from exhaust manifolds and now the BBK throttle body. Fueling is by an in tank pump with no return line.

Many thanks for the advice Sean! Much appreciated.

Best wishes
Dave

CrazyDave wrote:I dont follow press E in I2, is that key E in the analysis software? I have been resetting error in the Manager diagnostic page, keeps coming back with Ref Sync errors, Noise A/r.

Yes, in I2 if you press E it will show errors in a pane at the top of the screen. Don't worry too much about the noise error, see what errors it gives when running.

My feeling is that the starter is failing internally, it shouldn't be that hard to turn over a stock v6.

I'm should be a MAP or MAF sensor defined, but there isn't in the file that's in the car. By default ECU manager saves the config within the log file.

Looking at the pulse widths when cranking, the 24 ish value is quite big, the 6 seems believable, especially when you say the plugs are wet.

Do you have a known good ECU file that came with the car?

Hi Sean,

I had a look at the first log file I downloaded 26th Jan, attached, and it looks like this has some engine running data,if that helps?

Ta
Dave

Since we can get the M800 config from the logged data, I was able to compare the configs. The fuel table is vastly different in the low TPS / RPM regions. It looks like it just doesn't have enough fuel for the amount of air being it's getting. The old file had values like 30 @ 5% TPS / 500 RPM, whereas the new table has 15% at the same condition, which would be used right after it leaves cranking and starts running. So you've removed 50% of the fuel.

I noticed that when the engine was running the TPS was reading 4.1%, but all the failed starting attempts, the throttle now seems to be 5.5 - 6%. Perhaps you you might try closing the throttle stop, particularly as you now have a different throttle body.

I would suggest you methodically try changing the fuel in the 5-10% TPS / 500 - 1000 RPM cells. Increase all those cells by about 20% and try starting, charge the battery if necessary between attempts, stop if it's cranking slowly. Then repeat 20% again. Continue until the fuel table values are 35-40. If that doesn't do it, pull the spark plugs and make sure they are not fouled (might do that first!). Share a another log and we'll help you look.

Also, I notice your Fuel Cranking Comps are really high -- this is another sign that the fuel table is too lean in the cranking area. The Normal comps are around 250 max, and tapering off quite quickly. Revisit this once you get it starting, but I suggest you put the same values in the zero RPM cells as 500-750 and see if you can then reduce the cranking compensation.