Right, it will change the trims... but did they change inversely? It just didn't work like that for me under quite a bit of testing.

If it worked for you, then I can't recommend against it

 

so lowering the higher cells removed some fuel and made your trims better, please check your wideband too. You will be leaner than before throughout your wot.
(This would be the same effect as changing your injector scaling.)

just for giggles, next time it you play with the compensation while tuning the idle, adjust the bottom three cells. ~ 19, 25, 50.

Also, put 15 or 16 in your idle rpm area if you want to lean immediate cold startup. 10s would be really rich. The open loop at startup is around thirty seconds or less. But maybe there is a blending or open loop and closed for awhile longer?

 

I do not understand how fuel trims that are in the good range (+/- 3%) would require a rescaling in order to allow for good cold idle / cold drivability. I say this because my trims are quite excellent and drivability when warm is outstanding.

There has to be a cold idle routine somewhere that retards timing a ton to rapidly warm up the cat. I don't think the EGR stuff does much for cold idle other than recirculating unburnt fuel to allow for better emmisions.

I recall in the 96530006 rom that there was a "timing table unknown" that had a huge timing hole in it where the car would be running if cold. Could this table be the missing link I am talking about?

 

Nope, they changed as I expected from reading that. When both of my trims were positive, I lowered the scaling value and the trims came closer to 0 and vice versa. When LTFT low was more positive (or less negative) than LTFT mid, I increased the latency values and it brought LTFT Low down closer to LTFT mid. I didn't do anything different than what it says to do.

You said there was a difference between latency and dead time? What is it, cuz I've always understood latency to be dead time, for any solenoid actuated anything.

 

This one?

 

All I'm saying is that it worked for me, and wonderfully so. I didn't think it could get any better but it did. I don't have any scientific evidence to base that on... and I know that is not the best way to do things but when something just works and science was failing (or at least failing to come up with an answer) I'll take real world results.

Disabling that timing hole did nothing for my AFR and I thought you (and or at least a few other people) posted the same results...?!

I think the thing about the EGR is that specifically that periphery bit may disable another routine, and that is why people are having problems with it. In any case, it does not have anything to do with the situation because the people with that problem have re-enabled that bit, and used the alternate non-periphery bit to disable it and not had a problem. I'm confused as to why it keeps coming up because I thought we were beyond that being a possible answer, and it is now way out of scope.




I believe latency is the time to open, dead time is the time to close... but I could be wrong. Some systems assume them as the same thing, although the DSMLink value could have been mislabeled. I was never clear if it was an additive value applied to the total set of latencies. If so, then it is likely that it was mis-labeled as latency can be affected by voltage. Dead time should not be effected by voltage because it is how long it takes the item to fall to a rest from full actuated.

(.... there is a big IF I'm understanding things correctly)

Yes, that is the one he is talking about. It is also in 88590015

 

I've always understood latency and dead time as being the same thing.

 

No that isn't the table I am talking about.....This is it.

 

Paul, open a 70015 rom with the new xmls and look under Engine Coolant Temp Trim for ECT Mapped Ingnition trim. Is that the table you're looking for?

 

did you have that table in a 94170015 xml? I never found it in 70008.

 

I found it in one of the other threads about new tables for 96530006. See post #83 above.

What is it and is this the missing link for cold drivability?

As for the other comments....I am not trying to argue. I just do not believe that we have identified the specific cold drivabilty table.

I agree completely about the EGR routines....there is something we are missing.

I appreciate everyone's assistance.

 

Okay thanks to Lucas & Aaron (John Bradley) at English Racing for giving me an idea that I think can be used to solve the cold start issue... I went down to English Racing yesterday for my timing belt service and I was explaining the cold start issue to the guys. I showed Aaron my rom and he just suggested that I run my car in open loop the entire time and to not worry about the fuel trims... I seriously don't have the time or energy to tune the "closed loop" fuel maps, but he showed me what I needed to do to make this happen. Well instead of tuning the entire "closed loop" fuel map I changed just enough of it to combat the cold start issue...

1. Change Open Loop Load #1 & #2, and Open Loop Throttle #1 & #2, tables 500-1500 to 10.

2. Start the car up and log the AFRs at idle for 1000 and 1500 and adjust accordingly just like any other fuel cell... (STFT will not respond nor will the fuel trims adjust for these cells anymore).

Here is what it will look like...

 

My ride has absolutely no start up or idle issue but that engine cold timing routine really feels wrong.... especially on a catless car.

Now I've tired the EGR bit 11 thing and that didn't fix the problem.

I need to know how to find the quoted map for editing. I'm still using ECUFlash 1.30 and it doesn't show any of these maps. What version do I need to fix the cold start timing map?

 

Jeff....I found it by searching around in the EcuFlash forums.....Took me a little while.

That table looks like it retards timing for rapidly warming up the cat. For those of us running no cat....it is useless....So it would be great to change it to look simular to our tuned timing maps.

This is, of course, if this map is valid and what routines call it out.

Anyone know? ? ?

 

Freddy....how did that work out for you ? ?