BMW / Wells TPS users - how do you have your Variable TPS wired?
 

On my '92, the TPS signal wire is on pin 2L of the ECU (not labeled/unused on Brain's diagram). I plan on using that wire to go to megasquirt, but on my parallel boomslang, should I splice or cut it? I'm assuming the stock ECU won't understand the variable TPS, but how does the ECU get the information, for example, the WOT data to turn off A/C, etc?

How does everyone have theirs wired?

With the 1.6 TPS (-0161)I have, there is outputs at 1.5degrees and 70 degrees for idle and WOT. I don't know what the stock ECU would do with the 'wrong' data, but it probably wouldn't like it. I actually have a 240SX TPS that I use for all my VTPS stuff, it has the same 3 pin connector with idle and WOT switching, and also has a separate pigtail with VTPS wiring. Its a clever little deal.

If you modify your TPS like this: https://www.miataturbo.net/forum/t12239/#post157397


wiring your boomslang is easy. I'd have to go downstairs to look at my notes as to the wire location, but it's zombie killing time.

That's exactly what I'm gonna do, except I'm using a BMW and not a Wells. What I need to know, though, is whether to do a splice or a cut on the ECU pin (2L, wire color lt grn-white on my 92). Ben's post doesn't address that.

Another thought, how does the ECU know when it's WOT for the A/C?

I'm using a BMW vTPS. Not sure my install would help though, as I'm using an MSPNP. I didn't add any wiring to the ECU, just used the stock stuff.

i assume your doing a piggyback MS? how about turning off the a/c when you go wot?


here's what i do:

send your 5vref out through 1N, cut the lead to the stock ecu.
send your TPS signal out through 2L, cut the lead to the stock ecu.

wire the TPS as outlined in the above link. The WELLS makes more sense since you can use the stock connector and don't have to hack up your wiring.

Quoted for truth. I ended up opening a spare TPS I had to steal the pins. I wired pigtails to those pins and popped them into the stock female connector, and put some bullet connectors on the opposite end. The bullet connectors snap onto the BMW pins. Basically, a short little harness so I didn't have to cut off the stock connector. Not as ugly all wrapped in tape, but if I had known about the Wells a year and a half ago...

I know what you're saying about the wells and using stock wiring. I'm gonna see if I can't find a TPS at the junkyard and hack it up to use the connector so I can make an adapter out of it.

Anybody know of any other cars that use the same TPS?