calibrating TPS issue
 

When I hook up my MS to my laptop to calibrate the TPS, I get funny values,
like 50 closed throttle ADC and 54 or less WOT ADC :bang:
tried it a few times and sometimes WOT ADC is lower than closed throttle ADC
I didn't touch the stock wiring and I trust the wiring capabilities of Scott, so tell me where do I screw up?

Unnaturally Aspirated, that's awesome.

Weird, I guess your following the procedure correctly? Dunno unless your sensor died on you or it's not wired up properly.

Which tps sensor are you using? Have you tried moving the tps manually by loosing the two screws and adjusting it?

I'm using the stock '94 one. I thought it had a variable TPS but the readings make it seem like it's an closed/WOT switch like to '90-'93 ones?
I'll get out the DMM after work if the weather is reasonable.

The '94 TPS does have one set of open/closed points, Between the Red wire (Idle) and the Blk/Blue wire (GND).

To verify your wiring at the ECU, you should have:
1- Red / Black wire (2M) connected to the TPS input (22)
2- Light Green / White wire (2K) connected to VREF (26) where you will find +5V, and
3- Black / Blue wire (2D) connected to GND.

That last one in particular may be an issue for you if this is a standalone install. On all of the 1.8 cars, the O2 sensor, the MAF sensor, the CLT sensor the EGR sensor and the TPS sensor all go to ground through the stock ECU. If you pull the ECU without then joining the appropriate wire to the MS's GND, a bunch of things stop working.

Oscar, its highly possible, (read almost positive), I forgot to hook up the TPS to your harness as I built about 20:1 for a 90-93 which don't have a variable TPS.

check if you have a solid thin blue wire and gray wire on the harness.

I'll go check now

so there's three blue wires on the standalone harness. one thin blue one that goes to the Knock input connector, a blue one with a white stripe 7 pins below that and a thicker blue wire that splits into two black wires in the bottom left corner
no grey/blue wires to see for the rest

k, then i didn't add it....arg. did i built you a stand alone or boomslang?

standalone

you'd have to add two wires into the connector and run them into the boomslang.

if you open the hood of the db37 connector....

you need to add one wire between the two blue/wht ones, pin 26 - to 2K (LG/W) on the boomslang. This is 3 over from the blue/white wire, next to the fat gray one.

you need to add another between pink and yellow, pin 22 - to 2M (R/B) on the boomslang. This is 2 over from the blue/white wire, next to the fat gray one.

http://www.boostedmiata.com/MS/db37_MS_pinouts.jpg

then it shall work....

mm I see. I'll go ahead and try that

got around sending me the .msq file yet btw?

i forgets....you can download it off the MS itself at this point :bang:

i forget too, but now my harness is all apart to solder the wires ;)
I'll try and do that tomorrow.
is it worth resoldering the wires so I don't have to swap the plugwires on the coils or just leave it and swap plugwires

might as well swap them around....easy enough.


pin 31 and 36, the highlighted one on the diagram above and the brown one near the end.

I just sacrificed an old computer PSU for a quite large amount of 18awg wire :)

on the yellow connector, there is a wire going from the TPS position (2nd pin from the one with the resistor on it) to pin 26 on the DB37 connector, though it's black one. Do I still have to add a wire from that pin to pin 2K on the yellow connector then?
(wiring is not my strongest point ;))

fuck I hate soldering little pins :fawk:

care to send me a fresh one with all the wires in the correct place? :x:

its only four total solder joints. :)

I know, but I got more burns on my hands now than correctly soldered wires ;)
I have not soldered in at least 5 years (highschool :giggle: )

I added a blue wire between pin 22 and 2M and the one from 26 to 2K is almost finished.

I'll probably wrap this up tomorrow :x:

I'll let you know :)

Is it really taking you 2 days to solder 2 wires?

it does when I only have time after work and get my shit together. plus I got fed up with using a crap soldering iron.
it also doesn't really help if I'm the only one with mechanical skills in the house.
I'm not making up excuses for taking 2 days to solder some wires, but merely explaining :)

/bitching :)

finished up the wiring and tried recalibrating the TPS
got 80 on closed and 166 on WOT, does this look normal or did I screw up somewhere else. car wouldn't start, cranked real slow but that may be due to the battery.

megatune started bitching about code variants, 29y3 found in MT and found 29Q in the controller (the MS itself?) ?

more things to fix :)

Moving in the right direction, but it seems wrong to me. You should be seeing values closer to 0 at closed.

What's the history of this TPS? Is it a grungy old original unit that may be past its prime?

still the original one from '94. if it were to give up the ghost, wouldn't I have noticed it before when I was still running the stock ECU?

need to get my IAT, LC-1 and knocksense wired in too..

If you have access to a multimeter, you can measure the voltage on the Red/Black wire (relative to ground) as you open the throttle slowly by hand. It should progress smoothly from ~0V at fully closed to a ~4.5V at fully open. An analog meter, if you can find one with a 0-5VDC scale (or close) would be ideal as you'll be able to see any little bumps in the signal.

I'm seeing 22 and 186 for zero throttle and WOT. So 80 sounds a bit rediculous. Can you adjust the TPS's at all? Maybe it has been turned so that it doesn't get it's full range of motion.

do it again, as long as it's always what it gives you, then you should be in business.

I'll get out the DMM like joe said, then I'll see if it gives consisten values closed and WOT.
will these funny values make the tuning harder as the throttle position is displayed less accurate?

It won't cause any issues. You have to tune your own acceleration enrichments anyway so it shouldn't make a difference.

Just make sure that it's linear. When mine went bad, it actually went up-down-up as you opened the throttle.

ok, my DMM has some sort of linear gauge too so I'll check for any spikes when testing the TPS to make sure it is linear :)

should be able to check that after work today

I tried recalibrating the TPS in megatune, still gives me 80 closed and 166 WOT ADC consistently. the TPS gauge in megatune reads from 27% to 62% closed and WOT:hustler:

I also tried to start, but I only heard a fast clicking noise:vash: like the startermotor slipped past the teeth on the flywheel, it seemed to loud for a starter relais
I'm stumped:bang:

Maybe reading this will give you a few new ideas to try, specifically the last one. :)

https://www.miataturbo.net/forum/sho...light=throttle

I'll give that a shot, thanks :)

I hooked up the laptop again, TPS is giving consistent 80 closed and 166 WOT, so that should be ok. got the gauge working too now, shows nice 0-100% throttle now :)

any ideas on the clicking noise?

and what's this?
http://i142.photobucket.com/albums/r...9/MTerror1.jpg

working gauge:
http://i142.photobucket.com/albums/r...9/TPSgauge.jpg

That error message shows you have MegaTune configured for 029y3 through 029y4 firmware, but your Megasquirt is running a different firmware, most likely 029v. (Firmware versions change their signature only if they need a different configuration, so 029q through 029v have the same signature.)

how do I change that in MegaTune, a matter of a little change in the ini file or is there more to it?

[/stupid questions]

looks like you simply don't have the correct firmware locally on your machine.

Could just need to be turned on in the configurator, because it's obvious you loaded it with the 029v firmware.

I'm just using whatever you preloaded for me in the MS

Easy way is to go to the Software / Downloads section of our website and install our MegaTune package - this one has been configured to let you select the firmware when MegaTune loads.

great, I'll try that. thanks :)