Oxygen (Lambda) sensor
From WikiLEC
About
The Oxygen (02) Sensor monitors the amount of unburnt oxygen which passes out of the engine through the exhaust manifold. This reading is then used by the ECM to determine the correct input fuel mixture. It is not the only sensor that controls fuel mixture, but it is regarded as the 'primary' sensor, because ultimately whatever is exhausted from the engine is the 'actual' result of the burnt mix - whereas all the other sensors read pre-burn factors such as air and coolant temperatures.
Oxygen Sensors only came into mainstream production use in the early-mid 90s, and hence not found on the N/A or SE Elan M100. However, it is possible to convert the SE to use an O2 Sensor.
Replacement Parts
In the LEC repairs area, Jade and Nitro identified the Discount Auto #11039 as a direct replacement for Fed Elans, Doug also identified the Bosch #13277 and Charlie the NGK #21012.
Having dug around unsuccessfully on UK sites to find these part numbers, it looked like I was going to have to get one in from the US.
However, I happened upon one on a well known international auction site for a Rover 218 VVC. The only apparent difference is that the wires appear longer than the Elan's which are about 40cm long. Fortunately, a European Bosch number (10 numbers) was on the photograph so a quick search on 0 258 003 229 threw up the Just Lamba website whose details confirmed the Rover part appeared to have the right connector but that the lead length was 59cm. Never mind, 13 lines above it are the details for the 0 258 003 193 which has a lead length of 39cm. A further search of the part number throws up the 1300 Mk1 Mini from Seik for €24.
The European Bosch reference for the O2 sensor would appear to be 0 258 003 193 from a 1300 Mini {although I've just noticed it's four wire not three wire and the pins are spade rather than round ... bugger!} Also very useful information at Lucas Electrical
There are some other possible replacements listed at OxygenSensors.com under:
Year: 1991
Make: Isuzu
Model: Impulse
Sub-Model: RS
Engine: L4 cyl (1.6 L,1588)
These are:
Walker #250-23127 3-Wire
Denso #234-3014 3-Wire
| This site also lists a 'Universal' part #250-23000. Ignore this, as the fitting is not correct |
Replacing
- Apply copious amounts of penetrating oil, heat and/or cold to get the old sensor out.
- Use an 18mm O2 sensor socket which has a slot up the side for the lead.
- Check that the thread in the exhaust system is clean and in good condition before attempting to install the new sensor. Don't drop any swarf into the pre-cat!
- Handle the sensor with care to prevent damage - dropping a sensor could inflict damage to the ceramic, which would not be apparent during installation.
- During production an anti-corrosion compound is applied to the threaded portion of the sensor body. This is a sensor friendly grease compound and no other anti-seize compounds should be used as they may contain ingredients that could poison the sensor elements. Do not use any other cleaning or anti-rust solvents near the sensor body as this could similarly affect the element.
- Remove the protection cap just prior to fitting. Screw the sensor into place by hand then tighten to the specified Torque settings ensuring that the wiring harness is not twisted as the sensor is screwed in.
- Secure the harness using the correct fixings, ensuring that the routing does not produce any kinks in the wires, touch any part of the exhaust system or other hot components and does not foul any rotating parts.
- Reconnect the harness connector.
