No offense Mike, but I don't have a car sitting in front of me to look at to know which is top or bottom. I gave you a screenshot of the wiring diagram that shows a picture of the connector (with positions) and even gave you the colors.

That said, I think we are 99% sure that you are getting 5v to the TPS.

What is interesting though is the .5v that you are getting on the top wire.
https://www.miataturbo.net/attachmen...1&d=1397949410

According to that, the wire you are getting .5v from SHOULD be a ground. Instead of metering voltage, check resistance to ground. I am guessing this has something to do with your problem.

I will double check in the morning when I have better light but those are different colors than I have. It looks like mine are B/LG = 5v, B/R = Ground, G/B = .5v

I will verify everything tomorrow to be sure. But I wired the VRef to the B/LG, Ground to B/R and TP Signal to G/B

Thank you for your help (sorry, I was out to dinner earlier)

you wired it wrong.

b/lg is always a sensor ground.

You sure brain? That's not the way it looks in the wiring diagram.

B/R = Black with Red stripe = sensor ground
G/B = Green with Black stripe = signal
LG/R = Light-Green with Red stripe = vref

I am confused though because black/light green doesn't show up as a throttle related wire. Mind you, my wiring diagrams aren't for a 2003 but I have one for both a 2000 and a 2001 and they both agree with the colors and signals I posted here.

EDIT:

Rather than argue about it I just went outside and metered my own.
https://www.miataturbo.net/attachmen...1&d=1397967839

My wires meter out as:
B/R = Black with Red stripe = sensor ground (ground)
G/B = Green with Black stripe = signal (happens to be just under 5v at the moment for some reason)
LG/R = Light-Green with Red stripe = vref (5v)

I will try swapping the outer wires first as I am confident that the middle is ground.

May not be able to do it today as it is my wife's birthday so she is priority today.

So far so good. I ran downstairs while she is asleep and reversed the wires. It is much more stable (although the adc numbers are very high, 700+).

I can't check out the TPS with the car started yet because it will wake her :-)

I really do appreciate everyone's help as always

Attachment 110243

okay, sorry B/LG is different than G/B.

That's not what confused me Brain.

I was trying to fugure out if you had a typo and you meant LG/R or if you meant G/B. Either way, my references had neither of them as sensor ground.

I reversed the outer 2 wires and all is great now!

Thanks for all the help. I learn something new every day

I wasn't looking to be honest. All 90-97s use b/lg as a sensor ground wire and that went out the window in 99. so when I saw the reference to that I was like well there's an issue.

Looks like I was still correct about the wiring issue, lol.

Ahh, ok that makes sense. I wonder when they made that change. (Seems strange to do it after a year of NBs with no other major changes)

Just to follow up...I sent the MS to Peter Florance at PFTuning to check my soldering.Turned out that I had a bad joint at R9. He fixed that and now the TPS is stable and where it should be.

Thanks to everyone for your help