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Old 04-23-2009, 03:37 PM   #1
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Default Oh *****...

I need some help please!

I've a 96 Roadster, I've been happily MS'd for over 3 years, running in parallel with the stock ECU. the Wiring was a mess and I figured I'd convert to full standalone all good so far.

I've hit a few snags though..

Where do I plumb the TSP 5vref line into on the harness? from the Madracki wiring diagrams - page 9 bottom right, it looks like it should be Blue/Black, but that doesn't lead to anywhere on the ECU harness...

Which line should the tacho signal plumb into? is it 4L as per the above linked PDF - page 8?

Finally, I no longer have a working Coolant temp gauge in the instrument cluster...wtf? I was under the assumptioin that this is independent from the OEM ECU?

Many thanks all!
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Old 04-23-2009, 06:39 PM   #2
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Right from the link I posted above, I've finally found the tacho circuit, page 17.

there's 2 lines off the tacho 2k and 1H

1H is black/white and goes to the transmission control module?
2K goes to?? lost on that one...

Looking at that the temp guage is indeed run off the temp sensor, so why does mine not work with the OEM ecu not plugged in?
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Old 04-23-2009, 08:45 PM   #3
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Best way to figure out with wire is the 5vref on your car is to probe the TPS sensor plug at the throttle body. I think its like ltgreen/white or something with ltgreen in it though.
Could be mistaken.
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Old 04-24-2009, 01:57 AM   #4
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TPS: Find the two pins on the TPS whose resistance does not change when you turn the TPS by hand. Of these two pins, one is 5Vref and the other is the ground. Find the ground by checking the resistance between the pins and a known ground (engine, chassis). That resistance should be 1 Ohm or less. The other pin is the 5VRef. Look at the wires going to that pin, note the colour and find the same wiring on the harness.

Jim
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Old 04-24-2009, 04:03 AM   #5
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Cheers Jim and cjernigan!
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Old 04-24-2009, 05:07 AM   #6
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Ugh.... right connected the 5vref line to the light green/white wire and the sig wire to red/black, that should be correct right?

All I get is the TPS ADC slowly rising, and if i but a voltmeter across the two wires it drops back to zero, remove the voltmeter and they slowly rise again. I don't get it?

Also, when removing my old wiring I could've sworn my TPS sig was plumbed into the lightgreen/white wire, but looking at the wiring diagram that should never have worked?

I'm really lost on getting the tach and clt guages to work...

You know when you wish you'd never started a job?
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Old 04-24-2009, 05:19 AM   #7
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I have these wiring diagrams at home written on a piece of paper, i remember it being hard finding out where it goes (as most people here have ms'd < 94 with no tps) but it definately solders into one of the db37 connectors. I'll post up the wire colours when i get home tonight.

Also don't forget the 1kohm resistor otherwise your tach and possibly clt gagues won't work.
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Old 04-24-2009, 05:40 AM   #8
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Quote:
Originally Posted by Seal View Post
I have these wiring diagrams at home written on a piece of paper, i remember it being hard finding out where it goes (as most people here have ms'd < 94 with no tps) but it definately solders into one of the db37 connectors. I'll post up the wire colours when i get home tonight.

Also don't forget the 1kohm resistor otherwise your tach and possibly clt gagues won't work.

cheers matey appreciated.

I was under the impression that the 1k resistor was for 94/95 only?
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Old 04-24-2009, 07:58 AM   #9
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Replying to my own thread again... I've sussed my non working tacho, so happy days on that count

TPS is doing my nut in, it's wired correctly as I can see yet it doesn't work :( should the 5vref line be outputting 5v? or is it expecting 5v?

Also is there any reason my stock coolant guage should've stopped working, I get nada out of it can't see there being a fuse considering it's fed from one wire from the back of the head... grrr
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Old 04-24-2009, 08:26 AM   #10
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****** ay! got the TPS sorted, it needs a ground aswell as a 5vref dumbass!

now I'm full standalone, woot! just need to figure out why the **** my coolant gauge doesn't work...
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Old 04-24-2009, 09:17 AM   #11
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Excellent, no doubt soon you'll be able to help me tune my idle, mines a little rough and slow just off idle.
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Old 04-24-2009, 10:05 AM   #12
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Isn't the coolant gauge just run off the front sensor in the thermostat housing?

ECU runs off a sensor in the backside by firewall.
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Old 04-24-2009, 10:09 AM   #13
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1.8 so it's off a sensor on the back of the head.

Still I've fixed it now, seems the needle had fallen off......oh dear lord!
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Old 04-24-2009, 10:12 AM   #14
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i keep wanting to post in here, but i keep forgetting to go downstairs and look at my sheet with the pinouts....
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Old 04-24-2009, 11:16 AM   #15
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too late, all fixed now :lol:
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Old 04-24-2009, 05:55 PM   #16
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Quote:
Originally Posted by richyvrlimited View Post
Still I've fixed it now, seems the needle had fallen off......oh dear lord!
That one just made my day - thanks!
Congrats on getting it all working.
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