M20 ITB install

[Lugnuts]

Yup.

Firstly, I'm using a MegaSquirt. The factory DME expects a throttle position switch, so it won't work with stock.

If you refer to page 20 of the Product Brochure (available on the same site under "Related Documents"), you'll see it can be programmed to your requirements by the supplier, to supply different voltages across a specific range of butterfly movement (across 2 different channels - output wires) and clockwise/counter-clockwise/both shaft rotation. You'll have to work out what the orientation of the shaft is at idle, and how many degrees it'll move through to reach WOT...+/- some headroom. Can't recall what stock is, or if the ITBs went a different direction. You can request it be supplied with bare wires then attach a Bosch 3-pin to make it compatible with the stock connector. I adapted my stock connector to a Deutsch, since the TPS was sold to me by another forum user who had it installed in their track car.

From memory, I used RHD's adapter. The TPS bolt holes are compatible:

http://racehead.com.au/products-page/parts-and-accessories/m20-bmw-adapter-or-e36-tps-for-stand-alone-ecu/

Edit: correction, I adapted the TPS wiring to a Bosch 3-pin so I could revert if it all went pear shaped.

[zaq123]

even OEM TPS gave you trouble?

Yup.

Firstly, I'm using a MegaSquirt. The factory DME expects a throttle position switch, so it won't work with stock.

If you refer to page 20 of the Product Brochure (available on the same site under "Related Documents"), you'll see it can be programmed to your requirements by the supplier, to supply different voltages across a specific range of butterfly movement (across 2 different channels - output wires) and clockwise/counter-clockwise/both shaft rotation. You'll have to work out what the orientation of the shaft is at idle, and how many degrees it'll move through to reach WOT...+/- some headroom. Can't recall what stock is, or if the ITBs went a different direction. You can request it be supplied with bare wires then attach a Bosch 3-pin to make it compatible with the stock connector. I adapted my stock connector to a Deutsch, since the TPS was sold to me by another forum user who had it installed in their track car.

From memory, I used RHD's adapter. The TPS bolt holes are compatible:

http://racehead.com.au/products-page/parts-and-accessories/m20-bmw-adapter-or-e36-tps-for-stand-alone-ecu/

Edit: correction, I adapted the TPS wiring to a Bosch 3-pin so I could revert if it all went pear shaped.

[Lugnuts]

From memory, I tried 2 different brands of E36 TPS with the ITBs. Hella and another brand that looked a almost identical to a Hella, except the factory markings had been machined off. Both were noisy (like +/- 12% TPS position under load/decel)...but only while the engine was running. Smooth as glass at KOEO.

The P&G TPS was bought after I went back to stock, on the assumption that at some point I would try the ITBs again. The offer price was too good to turn down.

I was advised that in order to use the P&G TPS with the ITBs, you need to carefully modify the ITB shaft, as it's too long. Plus the ITB-firewall clearance is tight and the P&G TPS is taller than an E36 unit.

Want to point out that my issues were most likely the result of me half-assing something during install - not trying to throw blame on RHD.

[Kershaw]

You can't say back to stock and still be running ms. That's why you confused me originally.