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Over rich warm up


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Hey guys and girls.. I'm trying to get my head around a very rich warm up situation. I have pretty well sorted the idle mixtures when warm to sit very close to stoich on petrol. It starts really well but as it's warming up the idle mixtures sit at around 0.68 to 0.7 lambda and I can't seem to pull it back without backing off the fuel table by 20 counts then steadily increasing it as it warms up. 

I have set the warm up enrichment table to zero everywhere and this seems to have had little to no effect... I'd be very grateful if anyone has ideas on this :)

Cheers

Tim

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Hey Adam, 

log file of warm up and snap shot of the fuel window attached. Appreciate any ideas! 

Two things I noticed this time were the accel fuel % value was very high at first start up. I then noticed that the TP main value was going a bit crazy, particularly at first start up, then it calms down a little as ECT nears 80degC but never just sits at 0%

Makes me wonder whether the TP sensor is faulty and causing the ECU to think there's a sudden throttle opening and activating accel enrichment? 

Otherwise I'm a little stumped right now...!

Cheers

Tim

 

Log 2017-11-27 8;15;59 pm.llg

fuel window.JPG

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You're correct in that it mostly looks like it is due to accel enrichment being continuously applied because of a noisy TP signal.  It might be the TP sensor that is faulty - but since your MAP signal is also quite noisy I'm more suspicious something must be injecting noise into your sensor ground or 5V.  The 5V supply in the ECU shows steady in the log.  Can you try disconnecting the lambda (power wires) and see if TP settles down?   Otherwise I would be looking for a bad ground or something...

Also turn off IAT correction - in modelled mode this shouldnt be needed. 

 W0KJNni.png

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  • 3 years later...

can i steal this thread since i have a similar issue. i think i have all my warmup richments off. im in a process of copying data over from previous ecu and have not been road tuning it yet, trying to make it idle and warm up properly or at least understand how it works on link.

 

i had too rich warmup with my previous ecu also, so im not sure whats going on, thats one reason why i switched to link.

on previous ecu i restricted injectors during warmup to make afr reasonable. 

 

this is my first logging attempt, is it any good?  could this pinpoint too rich warmup issue?

warmuprich.llg wideband-.pclr

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looking at your fuel table, it doesn't look right.

I guess fuel map isn't tuned. so tune your fuel map before starting to play with warmup.

and injector dead times are still stock, so if you changed your injectors, update that too

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fuel map is not tuned, im only working with idle right now.

 

thats the confusing part, injectors, my previous ecu i chose the correct injectors from a list, but in link there is no injectors choice.

i only changed master fuel to 8 ms so i would not need fuel trim 

 

i have 1600cc top feed injectors

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you need to figure out roughly your dead times. what make are those injectors?

then tune your fuel map. then worry about the warmup.

to avoid flooding the engine, just reduce the number in the fuel map at that map and rpm

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fiveo bosch ev14 propably.

i have the sheet in my hand. 12.5 ohms and dead time 0.875ms at 14 volts.

edit, theres a whole table for dead times

where should i put that information?

edit: oh yea i figured it out now. the dead time table. but what about the master fuel 8ms?

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  • 9 months later...

Hi, back in action after a long break. 

we have done a rough tune that still needs shaving, but still, to my knowledge i do not have any enrichment activated at any times and i am still running too rich warmup. i also took about 40% off from the crank fuel table to start it properly, while having ethanol, i should add fuel.  i run e85 which should require a lot more fuel than gasoline, i have no enrichment and still too rich.  while warmed up, i have decent afr, if you look at the fuel table you see how much i have taken the fuel off to get a decent reading, actually even needs more to be taken off. but it starts way rich. shouldnt it be the other way if i dont have any enrichment? it should be too lean. but its the other way around. could the idle valve have some settings off?

i have updated the injector dead times also 

i had the same thing with my last ecu so its partly the reason i moved over to link.

thank you

rough.pclr

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Do a log of a cold start and warm up and look at what injector PW is doing.  If the inj PW is flat and the mixture is changing significantly then it is likely the injector.  Many of the 1600cc EV14 injectors where only designed for CNG and are absolutely useless with liquid fuel, the flow rate is highly sensitive to injector temperature.  

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Does lambda ever actually get close to target?  It is still only at 0.8 at the end of this log.  The injector PW changes very little, what change there is is due to the vacuum improving as engine warms up.  I would lean towards injectors being the most likely issue.  

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Thank you for looking into it.

Lambda only gets close to target when the engine is properly warm. I will check vacuum with warm engine to compare.

Under driving conditions the injectors have always worked well. I might then chenge them to 2000cc ones, these are ev14 also tho.

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Some of the unstable idle is due to the fuel table cells that it idles in all being different.  The fuel table should be flat around the idle region.  

The dip when the fan kicks in is because you dont have idle ignition control set up, a stepper motor idle valve is a relatively slow moving valve and cant compensate for sudden changes in load such as a fan, you generally use idle ign to take care of that.

 

6 hours ago, scoobra said:

Without changing anything, the warm idle afr is a lot leaner than cold idle. You suggest i should try different injectors?

As I mentioned earlier in your earlier log the ecu is commanding the same injector PW when cold as hot, so it is not the ecu making it richer or leaner.   If your injectors happen to be the old CNG ones (many of the 1600cc are) then they are renowned for high variability with temperature.  

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