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quick TPS Q flood clear. Not so quick anymore now

Old Apr 8, 2010 | 04:40 AM
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Default quick TPS Q flood clear. Not so quick anymore now

Had to move the car this morning because of some roadwork going on in my street and ofcourse it wouldn't start
Turned over but did not fire. Eventually hooked up the laptop to see it's in Flood Clear mode all the time. TPS ADC count reads 254 for both fully closed and WOT. Managed to change flood clear treshold to 255 and started right up, albeit a bit rough.

Is the 254 ADC count both open and closed a sign of a dying TPS or a pinched/fucked wire somewhere in the harness?

Last edited by Oscar; Apr 8, 2010 at 06:03 PM.
Old Apr 8, 2010 | 05:03 AM
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That'd be my guess too. Disconnect the TPS and see what it reads.
Old Apr 8, 2010 | 09:05 AM
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disconnecting the TPS at the throttle body doesn't seem to make a difference. Both still read 254 ADC. Going to trace any pinched/chafed/cut wires.
Old Apr 8, 2010 | 11:47 AM
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More weirdness. I verified that all the wires at the harness are in good order. Opened up TunerStudio and noticed both CLT and IAT pegged at -40 celsius. Started up MegaTune to check, gives the same readings, both -40. TPS still reads 254 closed or open in both MT and TS. Made sure the thermfactor, matfactor and airdenfactor (which I used with succes in megatune before going to TS) are in the projects inc folder. No dice. No CLT, IAT and TPS readings that make sense.

Any suggestions before setting it on fire?
Old Apr 8, 2010 | 11:48 AM
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did you lose your sensor grounds?
Old Apr 8, 2010 | 11:55 AM
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Not that I know off. Also noticed that the passenger side window won't go down i.e. does not react to switch. Drivers side is fine. Not sure if related, but if I damaged/removed a grounding point it might be.
I'll go recheck
Old Apr 8, 2010 | 12:22 PM
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TPS reading 100% and CLT/IAT reading minimum -40C values is a sign that either the signal grounds have gone haywire or the CPU is not reading the VREF correctly. Check either.

Jim
Old Apr 8, 2010 | 02:15 PM
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Cleaned the grounds at the throttle body, redid and cleaned up the IAT wiring. This seems all good. Can't jam the prongs of my DMM in the TPS connector far enough to get a decent reading. What readings should I get from the 4 wires?
Old Apr 9, 2010 | 04:28 AM
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So I found a pin, no. 31 on the DB37 connector that broke off. Wire is still on it, but pin doesn't make contact inside the connector. Jamming it in doesn't make a difference.
Old Apr 9, 2010 | 04:52 AM
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Normally, out of the top my head, pin 31 is IAC2B. Since we don't use a 4-wire stepper IAC, this is used for something else (what?). On one of the 4 pins on the TPS connector, you should get 5V. The VREF is at pin 26, also check if the component F2 (the small disc near the DB-37) is in place and if you get 5V on pin 26.

Jim

Last edited by Reverant; Apr 9, 2010 at 05:29 AM.
Old Apr 9, 2010 | 08:41 AM
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Pin 31 is typically used for the coils...
Old Apr 9, 2010 | 09:17 AM
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typically as you wired my harness that way too scott?

Thanks Jim, wil check for 5v at TPS
Old Apr 9, 2010 | 01:01 PM
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Well there is no "typical" method of wiring on a MS, maybe you've grown accustomed to your builds.

Jim
Old Apr 9, 2010 | 01:04 PM
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typical in the way the majority of us miata guys run our spark outs through...Oscar yours should be the same, since I built it; pin 31 will be one of your spark outputs.
Old Apr 9, 2010 | 01:34 PM
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managed to put the pin back into the connector far enough apparanty. Car runs ok-ish, idles at ~2k rpm. Used to be 1200-1400rpm. Still need to figure out the sensor and TPS issue though. I'm sick of this
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