Starting problem

Discussion and support for MoTeC's latest generation ECUs

Re: Starting problem

Postby Sean on Sat Mar 06, 2021 11:34 am

That would explain the pulse width. David, what's your thoughts on no MAP or MAF defined? Am I missing something that's telling it to not consider MAP in the fuelling calcs? Cheers
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Re: Starting problem

Postby David Ferguson on Sat Mar 06, 2021 11:36 am

He has the Eff Calc Method set to 1 (Throttle Position). So this an an Alpha-N fuel and ignition map (because Load Calc is also using throttle).
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Re: Starting problem

Postby CrazyDave on Sat Mar 06, 2021 5:28 pm

Many thanks David,

Re. The logs the one from 26th Jan was the original, as you say the fueling was reduced, but I had the same problem with cold start. I also changed the ignition timing around zero and cranking speeds.

I have a map from another car, 3.5l duratec on itbs, and was using this to compare and try to identify differences, unfortunately, this map uses a trim of 45% and a simple cranking comp, whereas the car with the problem has no trim but a cranking compensation map. I used the main fuel and timing from this car in my later log/map.

I shall reset the main table and try adjust the cranking comp as you describe.

Re. The throttle body, it is drive by wire, in the ‘closed’ position the new throttle body has a small opening, whereas the std Ford one was pretty much closed - where/how do I adjust the opening, there is no obvious screw adjustment?

Many thanks David.
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Re: Starting problem

Postby David Ferguson on Sun Mar 07, 2021 3:24 am

OK, I didn't notice the DBW setup. Throttle translation (how the pedal position relates to throttle position) is controlled by the table Adjust->Functions->Drive By Wire->Position Translation, plus the Drive By Wire->Comp table.

Your Position Translation table has 4% for 0% TPD (Throttle Position Driver). The Comp table adds 1.5% based on the Run Time and Engine Temp. When warm it is only adding 1.0% and removes that after the engine runs for 2 seconds.

So, you can adjust both of these tables to get good starting behavior both hot and cold. You just need to figure out what the engine wants and give it that.

Happy Tuning!
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Re: Starting problem

Postby CrazyDave on Sun Mar 07, 2021 4:42 am

Hi,
some updates on queries and advice.

I cant find a MAF or Map sensor, this may be because we live in a fairly flat country !

David following your advice I went back to the original map, saved circa 26th Jan, and just reduced the cranking comps in 20% stages, the 3rd and 4th iterations gave consistent firing but no pickup and run, logs attached for ref.

Sean, not 100% on your suggestions on using i2 for the diagnostic, I tried ctl E and got a popup screen with several pages of statii that I dont comprehend, sorry.

3rd iteration is file ending 503, 5th ends 507, 4th ends 508. Think I used a bit of throttle in iteration 3, it seemed to improve engine speed but just wouldnt catch and run.

appreciate your advice and comments.

ta
david
Attachments
20210306-0621508.ld
Iteration 4
(125.09 KiB) Downloaded 74 times
20210306-0621507.ld
iteration 5
(126.26 KiB) Downloaded 66 times
20210306-0621503.ld
Iteration 3
(218.84 KiB) Downloaded 68 times
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Re: Starting problem

Postby David Ferguson on Sun Mar 07, 2021 5:37 am

It looks to me like it was closer to starting before you lowered the starting comps. The injector pulse width was 15ms, when it seems to fire and the revs go to 500+

It looks to me like it's just not getting enough fuel.

Have you changed injectors, or fuel pressure since this car was last running? With this ECU calibration did this engine run at full throttle with good fueling (Lambda around 0.88 - 0 .90?)

If it hasn't been tuned yet, then perhaps your problem is really a setup issue. So since you tell me someone with a similar setup requires 45% fuel trim -- I suspect that the parameter Injector Scaling (iJPU) is incorrect for your injectors/fuel pressure. I would try changing Adjust->General Setup->Fuel->Setup->Injector Scaling (IJPU). Add 1ms, answer NO to the Interpolate question, test starting, and repeat if it seems to be helping.

Alternately (if this was running before, and it's just the startup/idle that needs adjusting), the steps I recommended before (modifying the all the fuel table cells in the area from 500 RPM to 1000 RPM , from 5 - 10% throttle, by increasing the table amounts 20% at a time).

BTW -- with all this failing to run, you really need to keep an external battery charger on the battery. Also give the starter a chance to cool down if it doesn't fire up right away.
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Re: Starting problem

Postby CrazyDave on Sun Mar 07, 2021 7:48 am

Cheers David,

I had a charger and jump battery attached for the tests today, there was usually a good delay between each iteration, to pull out plugs and give them a chance to dry, tho the starter is taking some stick from the repeats.

I raced the car 27th sept, every cold start was a pain taking maybe 10-12 attempts each time getting closer to running, picking up to idle very reluctantly and not taking any throttle till warmed up. Hot starts were perfect. I had just bought the car and it was supposed to be race ready. I have fitted fresh NGK LTR7ix plugs in the originals were very black and sooty,i thought i had some softer 5s to try but have put them somewhere safe!

The changes since the race are
The bbk throttle body,
Fresh plugs ngk ltr7ix, same as originals
Replaced crank sensor, oe Ford
New air filter
Injectors cleaned, calibrated and refitted.

I will do as you suggest with the main fuel map, adding fuel in the cranking range and zero rpm fuel at 500-750 level. Should I reset the cranking compensations back to original or leave at iteration 3 or 4 ?
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Re: Starting problem

Postby David Ferguson on Sun Mar 07, 2021 8:59 am

I would leave the cranking comps the same as before (that is one reason I didn't suggest changing the 0 RPM column as it will influence the cranking fuel). If you get starting and idling working, then copy the 500 RPM low Throttle sites to the 0 RPM, and go back and adjust the cranking comp to see what it wants.

Since you say it starts and idles warm, you would think it's a compensation (cranking compensation, engine temp comp) that is out here, but with the change to a new throttle body, perhaps there is just some more idle tuning that needs to take place before you re-visit the comps when cold.
David Ferguson
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Re: Starting problem

Postby CrazyDave on Sun Mar 07, 2021 5:34 pm

Many thanks David,
I’ll have a look at those later today and report back.

Cheers
Dave
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Re: Starting problem

Postby Sean on Sun Mar 07, 2021 7:24 pm

Do you have a log file with it running when warm you could share? I'm following along with David's diagnostics :geek:
Shouldn't the lambda sensor type be set to 0 if receiving the lambda over can from 2 x PLM? Not sure it actually changes anything :lol: :lol: :lol:

EDIT: I've been looking at some of the other settings, seems to me like it's not been fully set up. Plus and minus 30% trims on the closed loop fuelling, no FP comp, really basic battery comp.

Dave, in I2, just press "E" Cheers
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