88'gxln/a

what does the 20,000 mile sensor do?

Icemark

sends signal to the ECU to change the map after break in

Bambam7

Ya, the retarded thing is that it will flip back to the initial break in maps again at 100K to 120K, and 200K to 220K, and so on!
I wonder what the differences are... probably runs a tad richer...

Wankel7

Are you serious? So that is freaky stuff. Can't you just take the thing out?

James

HAILERS

Changes the Port Air Solenoid valve schedule at twenty thousand miles.

RETed

Uh, and how did you deduce this brilliant deduction?&nbsp You ever took the instrument cluster apart before?&nbsp The 20,000 mile "switch" is a separate counter from the stock odometer.&nbsp It does NOT reset every 100,000 miles.



-Ted

Bambam7

I beleive the switch gets the signal from the odometer cluster- and ingnores the sixth decimal place... this was actually demonstrated.... try checking the ECU harness voltage on the wire from the 20K switch on cars with different mileages. (one with 110K, and one with 80K or 130K) You will actually find that you get the same condition from 0-20K as you do from 100K to 20K. (+12V, I just can't remeber if it's inside that mileage spread or outside of that mileage).

RETed

1987 Turbo II
Mileage:&nbsp 115063
20,000 mile pin-out - "1O" - blue/black
VDC measured with DMM:&nbsp +0.01VDC

1988 Mazda FSM states...
Lead 1O, "mileage switch" - "approx. 12V (below 20,000 miles) | below 1.5V (above 20,000 miles)"

You're ******' wrong.


-Ted

Icemark

Thanks for clearing it. I was under the impression that the computer ignored it as well after the first trigger ended.

Do you think there is any advantage to resetting the second odometer when replacing the motor with a new or re-built one?

RETed

Rumor has it it triggers a richer fuel map and a slightly more conservative ignition map.&nbsp All this does is surpress power and decreases fuel economy.&nbsp I dunno about advantages on resetting that thing replacing motors, but I've broken in several rebuilt engines without messing with the switch with no obvious signs of problems or downsides; if you still with a conservative break-in procedure, then there's no need to mess around with this switch.

Hope you're having a great weekend - this stomach flu got me sitting on the toilet all morning!


-Ted

hIGGI

iTrader: (7)

so what it means ? does my car runs worse/better after turning 120k + ?

Icemark

ted's test shows that there will be no differenece after the first 20k miles.

No change at 100-120k miles no change at 200-220 k miles....

Bambam7

Oh well... maybe there is a difference in model years....

Check out the fc3s.org website too, under the 88 NA ECU check- it mentions that 6the digit mileage phenomenon too.

Wankel7

So mazda has a 20000 mile break in period. That is intresting. Wonder why they picked such a long time?

James

Icemark

I would bet its more oriented towards the cats and emission system than actual break in.

RETed

Could you give me a reference URL or how to get to that section?&nbsp I just went through the fc3s.org site rather quickly and found nothing obvious.

I've also went through my 1988 Mazda FSM, and I've found nothing that claims this also...&nbsp You got a page number or something?



-Ted

HAILERS

Ok. I'm a dummy. If I had a car with less than 20grand, does the 12v come from the combination meter going to the ECU, or does that 20grand sensor put a ground on the pin 1O(oh)? Looks like the sensor puts a ground on the ECU, but then again that does not seem right to me. Somethings not being shown at he combination meter on my diagram, me thinks. EDIT: I have a n/a with 200,400 miles on a junkyard combination meter and I'm going to take a look as soon as Juan Montoya wins the Austrian GP or when he and Schumacher bump eachother of the road, whichever comes first.

RETed

Sorry, the F2002 Ferrari chassis is not going to lose short of a major failure.&nbsp They showed it in this race - over a SECOND faster PER lap in the first 20 laps or so before the Panis full yellow.&nbsp This race got ugly at the end though, but you cannot deny the Ferrari DOMINATION (check the start out - BMW cannot even keep it's position!)...



-Ted

HAILERS

I was counting heavily on a crash b/t the Shoemaker and Juan Pablo, with the Shoemaker coming out on the short end. Also counted on BArrichello having his usual run of luck. The ending was not good and has brought bad feelings about Ferrari. On the other hand it is a team sport and the goal is to WIN. Barrachello will be given a race by Shumacher later in the year after he's sewn up the championship. Anyway, I did go to the 87n/a with 200,400 miles and sure enough there is 12v at the blue wire with a black stripe in socket 1O(oh). Went to the 87turbo with 136thou and zip voltage. Bambam is on to something. Or someone is. I was going to do the 20,000 mile check on the PORT AIR SOLENOID, but sad to say that requires disconnecting the tps plug which I won't do due to no plug and having the wires crimped on. Ain't that curious. Outside of the PORT AIR SOLENOID being effected at twenty thou, I know of nothing else. Anybody else know what else exactly is changed???????

RETed

It did leave a bad taste in my mouth, BUT you cannot deny it adds a little bit of intrigue to the whole soap opera rather than M.Schu running away with the race victory like the Spanish GP. I was talking it over with a friend on a what-if scenario...WHAT IF, it comes down to M.Schu and Barichello battling for the drivers title at the last race of the session...Ferrari has already locked up the constructors title...3rd place (probably some Williams-BMW driver) is a diiiiiiiiistant 3rd...the race plays out like this Austria GP...would Barichello move over just to give M.Schu the race AND driver's title???&nbsp Would there be team orders???

Whatever the case...&nbsp It looks like the superiority of McLaren is almost close to gone.&nbsp Sauber looks VERY strong, and Arrows is the other team opening eyes.&nbsp Jacque Villneuve looked like he was on crack driving around the race!&nbsp Was this a fluke race for him, or is this hints of J. finally being able to run with the top dogs?&nbsp Too bad his car blew up right before the finish!&nbsp Renault looked good last race, but they didn't do too well at this Austria GP...

Monaco is MY FAVORITE track!&nbsp Indy500?&nbsp What's that???


Don't you think 136k is a bit out of the 100k-120k window?


-Ted

HAILERS

It would be Barrachello's(sp, I know) last race for Ferrari if he didn't let M. Shumacher by to win. And 136k is just a few trips to Corpus Christi from being 200K. Just need to apply myself to the task.

NZConvertible

Maybe I’m a bit of an idealist, but I think Ferrari’s decision represents all that’s wrong with F1 today. Michael didn’t deserve the win, Rubens did. Simple as that. The argument that “it was a team decision” is a bit weak seeing as how “the team” took the same points regardless. At the end of the Season, if Michael loses the drivers championship by those four points (unlikely), then he just didn’t quite do well enough. If he wins by less than four points (again, unlikely), you can bet this discussion will come up again! It’s left a bad taste in the mouth of this long-time Ferrari supporter too. But like I said, I’m an idealist...
Sorry, I’ve nothing to add on the 20K mile switch except to wonder if I have one!

Bambam7

RETed- heres a link to the fc3s ecu check site
http://www.fc3s.org/ecu1.html
It's the only other place I've heard it mentioned in writing.
It is an interesting fact- but more interesting is the fact that some cars don't seem to exhibit the phenomenon (Like the TII you tested)
I'd love to find out exactly what it changes. My guess is that it would lean out the fuel a bit once the engine is broken in- as all 2 stroke engine tuners do....
But 20K is a LONG break in!!

RETed

That pages states that lead "1M" is the 20,000 mile switch input, while in the 1988 FSM, "1O" is the ECU input lead.&nbsp I just went through the 1988 FSM, and these is not detailed diagram linking the 20k mileage switch to the OD; I've opened up one of those instrument clusters a LONG time ago, and I remember a separate mechanical circuit for the 20k mile switch, but this was on a Zenki car - maybe the Kouki cars have a redesigned instrument cluster?

I do have a 1989 Electrical (only) FSM, and there is not detailed diagram if the circuit integrated with the OD, *but* it looks like the turbo has TWO mileage switches in it?&nbsp I think someone mentioned this a few weeks ago...



-Ted

Bambam7

Well, the ECU check outlined there is for the 89+... I can see no reason whatsoever as to why Mazda would include the 6th digit on the check on 86-88, but NOT include on the later models?? Is that the case?? And different on the turbos as well?

Very unusual....

Didn't someone dump the source code off the EPROM from an ECU a few years ago? I remeber mention of that here a long time ago. I'd love to see it.