AdoboMiata

iTrader: (3)

Hey guys so I have a 1994 Miata chassis with an NB engine. I am trying to calibrate the TPS with the 94-95 mspnpv2 and it is reading too high (1023).

I have an 99/00 skunk2 throttle body and I am using an NB tps (I believe the 94 TPS harness will not plug into the NB tps?)

I followed this reference and tested the harness if it is receiving the correct amount of voltage. The harness is receiving the right amount of voltage:

The 1994-1997 chassis did come with a 0-5v variable TPS. It is a standard 3-wire TPS with an additional fourth wire (red) which serves as a wide-open switch. Your standalone ECU will likely not use this fourth wire, so if you are changing the pigtail to a 99-05 style, simply heat-shrink over this unused wire. If you are using your 94-97 throttle body, there are no wiring changes necessary. If you are using the 99-05 sensor, wiring colors are listed below:

5v Reference:
94-05: Light Green/Red

Signal:
94-97: Red/Black
99-05: Green/Black

Ground:
94-97: Black/Blue
99-05: Black/Red

https://www.miataturbo.net/engine-pe...athread-80469/

Another question, I have 2 mspnpv2's. Can I simply use my 92 mspnpv2 on my 94 chassis? The 92 mspnp has my original map.

Onyxyth

iTrader: (2)

92 MSPNP won't work in the 94 without a patch harness, the pinouts are different.

If you let your car sit for a few hours, is the TPS immediately at 1023? I ask because a grounding issue would cause the TPS signal to go from 0 to 1023 slowly after you turn the key on. Let your car sit overnight and check the TPS signal immediately when you key the car to ON.

AdoboMiata

iTrader: (3)

Hey Onyx, thank you for the reply! I'm not sure if it's a grounding issue. When I checked each pin on the tps harness plug, it read 12v, 5v, and 0 (ground).

The TPS showed 1023 at no throttle and at WOT throttle. I assumed it was the tps so I was tapping it to see if it made a difference.. it stayed the same.

The TPS was fine when I pulled it from the other 92 shell.

When I tried starting it, megasquirt was showing me that the rpms were not kicking either.

AdoboMiata

iTrader: (3)

I forgot to mention, I used a speaker wire to jump the tps and car has no spark now...

Braineack

iTrader: (62)

your wiring created a 5v fault to ground.

this may help you (this is a 1.6L reference doc):

AdoboMiata

iTrader: (3)

Thanks Brain, I will report back

AdoboMiata

iTrader: (3)

Updaate:

I downloaded the new mS2/Extra 3.4.1 release Firmware from Megasquirt Downloads Firmware and Software - Megasquirt EFI

Car is reading tps even though I do not have a jumper on it. I was able to calibrate it without any jumper.. odd..

I calibrated the IAT, Injectors, wideband, and set the timing to 4g63. I am receiving no spark. I do have fuel ( I can hear the pump priming at key on)..

I attached my MSQ file and a composite logger. fyi, I am not sure if I did the composite logger correctly, but I'll do it again if necessary.

AdoboMiata

iTrader: (3)

second log. Cranking, then after a few cranks it would stop..

AdoboMiata

iTrader: (3)

changed cas... tried to start it, heard a loud "poof" sound and still doesn't start.