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Lamborghini V10 and V12 Engines -- Two Engines In One.

One of the often overlooked features when it comes to detecting engine faults with later Lamborghini engines is the fact that they are really two engines in one.  The front "Check Engine Lights" have a (L) Left and (R) Right lamp.  This not only means that if there is a localized fault with the engine you can determine on which bank of cylinders it resides on, but you can further localize the fault by switching components from one side to the next.

Fuel Injectors

There are 10 or 12 of then in the recent cars. A bad injector can give rise to a number of check engine warnings.  A bad "stuck on" injector will pump excess fuel into a cylinder causing an engine misfire, trip the check engine light and cause an OBDII code of 1303 (and perhaps others) to appear.  Please see "OBDII Codes" and "Injector Repairs" for more information on this topic.   If you suspect a faulty fuel injector - it sounds strange - switch it to the other side of the engine.  Then see if the check engine light changes sides also.

You will need a handheld OBDII reader to reset the engine check codes first. Remember the ignition should be on but the engine not yet started before clearing the codes. Then you can start the engine.


Spark Plugs

A faulty plug is usually apparent by just looking at it. If it is pitted up it can be corrected by simple cleaning and adjusting the spark gap if necessary.  One fouled plug alone often indicates a cylinder oil leak or a bad valve.  Nevertheless if you suspect a plug switch it from one side to another. See if the check engine light changes sides also.  To state the obvious - take care not to switch the spark plug wires themselves!

Spark Plug Coils

In the recent cars (Diablo 6.0L and later) each plug has its own spark coil. These are known as "Coils on Plugs" or COPs. While they are quite reliable and efficient if they go they are difficult to test. The coils are buried deep in the engine directly over the plugs. For this reason a hand held COP tester cannot get to them. Again switch a suspected coil from side to side as above to determine if one is at fault. See more on Spark plug coil repairs for more info. On the older cars the coils are away from the engines. Switching is probably not an easy option.

Engine Misfire Sensors

There are two engine misfire sensors on later Diablo's. (I do not know about the more recent cars). Please see the Engine Misfire Sensor Repairs for more information about these units. If you suspect one is tripping the check engine light try switching them from side to side. Again reset the engine codes first. See Repair Misfire sensors for more information.



    Engine Air Temperature (and other) Sensors

The air temperature sensors on a Diablo can fail from time to time. This will fire up the left or right check engine light. If you suspect one, you can switch them from side to side, reset the LIE computer codes/Check engine light and see if the L or R check engine also switched sides.

The same is also true for the catalyst lambda sensors (upstream and downstream) although these are more difficult to remove. So also for the coolant temperature sensors and gas pressure regulators.


The Lamborghini "LIE" Computer

This is the brain of the car engine. It is situated behind the passenger seat for Diablo's. Again it is really two identical computer boards (each in its own sealed box) sitting one beside the other. One computer for the left hand side of the engine, the other for the right. The left hand computer seems to have a few leftover responsibilities that the right does not do. For example controlling the Carter motor. However the other board appears capable of doing this if switched.
Each LIE computer box has two connectors. One pair is yellow colored. The other white. These connections (at least in Diablo's) can be switched if you again suspect a fault with a LIE board. The only thing different here is that the battery power kill switch must first be opened before switching. Again reset codes before starting the car. Take care messing with the $5000+ LIE computer in these cars is not for the faint hearted. However it does illustrate how wonderfully symmetrical the engine is in these cars.



This page was last modified on 03/12/2014

This page was last modified on 09/06/2014