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Discussion Starter · #1 ·
Need a little help to diagnois.... 92 with OBDI.

Last week converted to all Tubi, including test pipes.

Driving yesterday at 3K RPM..steady cruise, all temps normal.

L Cat light starts blinking (cats removed) continues to blink for about a minute, then L Check engine comes on. Car lost power, felt like one bank shut down, no throttle response.

This episode lasted for about 30 seconds. Then, all lights went off and car ran fine. Drove another 30 minutes or so and continued to run great.

What do you think?

I spend a long time reviewing the old lambo-talk tech site... I saw a post by JRV that said a bad coil could trigger the CAT Light... I suspect that's what it is.

Any other things I should check or what other failure can trigger a Cat Light?
 

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Discussion Starter · #3 ·
Naw that's not it....just got back from a quck drive...still doing it.
Think it's time to go to the shop...damn! Car show sunday is out...
Just hope she's back in time for a show next weekend.. it's a big one... I've been detailing this car for the last 6 days...
 

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L Cat light starts blinking (cats removed) continues to blink for about a minute, then L Check engine comes on. Car lost power, felt like one bank shut down, no throttle response.
This is "typical" of a ThermoCouple Controller going Bad! Just Unplug Them!!!!

The Thermocouples Activate at approx 1200-1300 degrees F to prevent Cat Meltdown and the very real Fire Hazard!!!!!

It's not possible for the exhaust gas to reach 1200-1300Degees F without cats!!!

The Controllers Shut Down "the offending banks" injectors (causing a power loss) in case raw fuel is flooding a cat which is a very bad thing!!!

Unplug the Controllers and go to your show!!!!

HTH's

:)
 

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Discussion Starter · #5 ·
Well.... I thought it might be the ecu that they plug into...the one by the right rear shock... Hmmm...unplug the bad boys? Crap, just put her on the trailer... will take her off so I can remove tire to get at it...

JRV ... if this works I'll send you something :)
 

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Discussion Starter · #7 ·
WHOOOOOOO YAAAAAAAAAAAAAAA

YOW ZA, YOW ZA, YOW ZA!

Not only did it work like a charm, the freakin car never has run as good!!!!!!

JRV - Something headed your way. Will be delivered on Thursday to you.

You'll know it's from me :)
 

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fl_355 said:
WHOOOOOOO YAAAAAAAAAAAAAAA

YOW ZA, YOW ZA, YOW ZA!

Not only did it work like a charm, the freakin car never has run as good!!!!!!

JRV - Something headed your way. Will be delivered on Thursday to you.

You'll know it's from me :)
Glad it was one of the common simple problems!!!!!

NOW LIKE I SAID "GO HAVE LAMMMBBBOOOOO FUUUUUUUNNNNNNNNN!!!!!"

:D
 

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Can someone explain a little more in detail on this? I think I may have the same problem. I take it you shoul not unplug the thermocoupler if the cats are on?
 

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Adam,

you are correct. If you still have Cats on it is NOT a good idea to unplug the Thermocouples. They are there to Warn about EXCESSIVE Cat Temps that can & have led to fires. They are prone to going bad, however the Cat Temp needs to be checked to insure the Cat is Not Overheating (or is overheating) before just replacing the thermocouples & control units. You can do this with an Exhaust Gas Analyzer (one bank running Rich) or with an Infrared Thermometer checking the Cat Temp.
 

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WOW! You guys really know what your talking about, reading through this thread i got excited when it all worked!!! JRV Your AWESOME!
 

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I take it when I plug in a wide band 02, it should be before the intake of the cats. I checked after the cats and it appears to be running 15 to 1 for air to fuel ratio which should be okay.
 

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Adam, you can't do this with a WB [email protected] Sensor because the Computers are controlled by the 02 Sensors, so if the stock 02 Sensor is disconnected from the computers they have no metering control besides the TPS & Water Temp Sensors, which is not how the system was designed to work. Additionally 15-1 is very rich. But this could be expected without the 02's to send Metering info to the Computers (LIE's).

I explained the two ways to check for the problem previously.
 

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ltadmin said:
Adam, you can't do this with a WB [email protected] Sensor because the Computers are controlled by the 02 Sensors, so if the stock 02 Sensor is disconnected from the computers they have no metering control besides the TPS & Water Temp Sensors, which is not how the system was designed to work. Additionally 15-1 is very rich. But this could be expected without the 02's to send Metering info to the Computers (LIE's).

I explained the two ways to check for the problem previously.
15 to 1 is rich? I thought that was stoich (SP?). My check engine light flashed two times which means low lambada signal...so would that mean with a weak signal...it increases the fuel?

Oh by the way the wide band O2 is a stand alone system.
 

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Get out your volt meter and select dc voltage. Ground the volt meter to the car. Use the red wire from the meter and connect it to the black wire to the lambda sensor at the connector (I know that sounds backwards). Just gently slide the boot back a little to expose the connection, but do not disconnect it. When the car is normal opp temp, the meter should bounce around .4 to .7 volts. Bouncing around is normal. Below .4 is too lean, above .8 is too rich.
Do not try to use the ohm function on the meter. It can short out the sensor. :)
 

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ltadmin said:
What do you mean by "stand alone system" ? is it plugged into the LIE's or not?

I does not plug into the LIE system. It's a Innovative Wide Band Kit I have. It will tell you the A/F real time by just inserting it into the tail pipes.
 

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SYNYSTR said:
Get out your volt meter and select dc voltage. Ground the volt meter to the car. Use the red wire from the meter and connect it to the black wire to the lambda sensor at the connector (I know that sounds backwards). Just gently slide the boot back a little to expose the connection, but do not disconnect it. When the car is normal opp temp, the meter should bounce around .4 to .7 volts. Bouncing around is normal. Below .4 is too lean, above .8 is too rich.
Do not try to use the ohm function on the meter. It can short out the sensor. :)

Thanks Synstr!! I will try that and post results by the end of the week hopefully.
 
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