Motronic - long, & not for the uninitiated.

[Robin-535im]

you may have made that statement rhetorically Robin...hehe. Just not cost effective for Mark or the buyer. Mark will tell you first hand, like most business big or small...its a numbers game. Because of the huge development cost...time mostly...laborious trial and error in large measure...in particular for a custom giddy up...no ROI. Would be cheaper to purchase a stand alone and do your own programming.

Or rather, someone with too much time on his hands goes out and instruments his car to measure WB O2, timing, pulse duration, RPM, inlet air temp, etc., then orders up a chip with timing and WOT fuel maps specifically tuned to his car...

Someone... perhaps someone who hits 6000 a few times a day? Seriously though, I'm really trying to understand why my car runs really great some days and just mostly great other days, and if there is something cost effective (key word there) to make it run really great all the time.

[George M]

the aftermarket is sprinkled (littered?) with guys just as you describe...over the top tuners who want to control everything. I have such a friend with a modded Buick Grand National (turbo V6) that run's 11's. He is forever tweaking his stand alone in pursuit of just a bit more performance. As to why your car runs good some days and not so others...depends on how precipitous the divide but humidity and air temp are HUGE.
Ask the nitrous guys who run bottle warmers :-) or the guys who dry ice their intakes before runs :-)

[winfred]

i don't know if the injection pumps were outta time or they were just that crude that they ran that rich, you could restripe the road with a diesel pup or luv. mom likes her old 740 turbo diesel but it's for sale because she really likes the 90 325isa i got her

but I think the Isuzu was even better

[Bellicose Right Winger]

Hmm....this doesn't sound right George. O2 sensors produce a continuous analog signal that's inversely proportional to exhaust O2. The DME needs a continuous error signal in order for PID control to work. The error signal is the difference between O2 sensor output and the setpoint established by the DME. Just knowing the O2 sensor output is too low or too high isn't good enough to make PID control work.

Paul Shovestul


[QUOTE=George M
.....All the stock primary 02 sensor does is tell the DME 0 or 1, that's it. It's a discrete sensor that tells the DME iteratively if it's rich or lean.
[/QUOTE]

[Jeff N.]

i don't know if the injection pumps were outta time or they were just that crude that they ran that rich, you could restripe the road with a diesel pup or luv. mom likes her old 740 turbo diesel but it's for sale because she really likes the 90 325isa i got her

[Paul in NZ]

runs purely on the preprogrammed maps, or there still some "learning" to do.I would guess not as there is no feedback .Why would my car take a week or more to settle down after say abttery disconnect or the changing of a icv or similar.......

[George M]

Paul S....A friend of mine designs engine management for supercharged cars. We have had many discussions about how the DME interrupts a narrow band O2 input. Believe the analog signal is converted for expediency...binary comparison against DME baseline iterated/sampled many times per second (doesn't the D in DME stand for digital? :-))as the DME needs to adapt in milliseconds to O2 input. The DME doesn't have time to interpret an array of analog input from the O2 and adjust injector pulse duration accordingly.