328 FI Oil Temperature Switch

Hi JRV et al,

Finally -about 9 months into this- think I have isolated my idle run problem (symptom: running rich and "popping" in exhaust).

The K-Jetronic/lambda uses an "oil temperature switch" to signal the ECU to accept input from the throttle microswitch idle position; effectively once warm with completes the circuit to ground to adjust (lean) mixture accordingly.

This is shown as #154 on the FIG 2 wiring diagram; note this is exclusively a FI control switch and *not* the oil temperature switch FIG 5 #13/part# 107576 that signals the dash gauge, nor the coolant tank switch #158, nor either oil pressure/low oil pressure warning light switches. It is shown as red/pink-striped wire into one side and black out the other, leading me to infer this is a two-terminal switch.

The left fenderwell multi-connector indeed has two red/pink-striped wires joining at the plug on the engine side, leading me to beleve the wiring diagram is accurate and the switch is located *somewhere* on the engine side. Retrograde grounding this terminal simulates a closed switch, and car idles properly.

Anyone know exactly where this switch is located? I've (erronously & experienced small oil slick -smile) replaced the dash oil temp switch, but have scrutinized as best as possible the lower aspect of the motor & searched the archives to no avail.

All suggestions much appreciated. If anyone needs help on the K-Jetronic/lambda system I've had to learn a reasonable amount and will be happy to share.

Thanks in advance,

Carl

Carl ,
I think that the oil temperature switch screws into a banjo fitting at the oil return hose from the oil separator on the front of the sump.

Brian

Thanks Mr. Brown!

Found this (after posting) late last night before going to bed. Part #115652. Ordering one tomm.

Thanks for your help,

Carl

Carl could you send me a pic of the diagram? I haven't heard of this part on 308s. Do they have it as well? I couldn't even find it in my Bosch books. Thanks.

Sure - this is from Carmine:



You're looking at "rear" side of motor adjacent to starter motor. It's listed as "water temp sender" but is actually an oil temp sender. Ordered this AM from TR for $22. It's in the parts book but is actually referenced in the owner's manual. I don't think it's a Bosch part (perhaps Veglia)?

Carl