TPS Conundrum

[rob0r]

Hey all,

I'm in the middle of my E28 M30B34 swap with the E34/E32 motronic 1.3 loom/sensors/ecu. I've fitted the loom to the engine but have found that the TPS plug on the loom is the 5 pin round variety and I had already fitted the rectangular 3 pin TPS (ex E30 m1.3 325i) to the throttle body. The ECU I have is E34 manual, 179 I believe.

I've done a bit of research but have come across conflicting advice.

1) I can use the "variable TPS" with the 5 pin plug which will work with the ECU. The conflicting advice here is that it won't route the WOT signal as this signal previously went through the autobox evu first.

2) I can cut the plug off and the three correct wires and all the signals are all present and correct to splice in the rectangular 3 pin connector.

Option 2 is my current favourite as I have spare (E30) looms to hand, but I've still not had firm confirmation on the best route to take.

Another option is finding an E34 manual loom or adapt an E30 M1.3 loom to the M30, but I'd like to avoid these if possible!

[jimbom30cab]

Option 2 should work fine and i think i have a spare 3 pin connector i can post you, i'll confirm the correct 3 pin wiring colours this eve when i get home

the other option of re-using a M20B25 manual loom is not a bad idea as long as it's motronic 1.3 as it will be the same loom, but you might have to lenthen some of the fuel injector wires (2 cables each). The advantage is there are plenty of M20B25 motronic 1.3 manual looms about but M30B34/5 manual looms are very rare.

Best thing to do is try to re-use the TPS you have and splice it on the current loom, if it works then great, if not get a M20B25 loom (dead cheap) and see if it fits (might not need any adjustments but if so it should be very easy and minor)

hope that helps

jim

[jimbom30cab]

forgot to mention,

I've got both M20B25 and M30B35 manual looms at home - did you want me to measure and compare them and report back??

drop me a text if so

Jim

[rob0r]

Thanks for the offer Jim, I have an M20B25 M1.3 loom on the floor of my workshop, I think I will just try splicing a three pin connector onto it and hope for the best!

[jimbom30cab]

ok, let us know how you get on

[rob0r]

Not quite finished this job yet but I've made some wire cuts...

Rectangular Connector from Motronic 1.0 loom
Brown/Blue
Brown/Black
Red/White

6 pin plug TPS wires on the M30 loom
Same wire gauge size as above
Brown/Blue
Brown/Black
Brown (maybe Brown/Orange)

Slightly thicker wires which I'm ignoring
Solid black
Solid brown
Solid yellow

I'll be joining the relevant looking three up and hoping for the best