Check engine ??? 1981 Fleetwood

[ThomasBorchers]

Hello !

At the dash board of our 1981 Cadillac Fleetwood the "check engine" light is on. What kind of problems shows the light when it is on ?

Thanks for your help in advance.

Tom

[jaxops]

Oil most likely. Don't run it until you check it out thoroughly. You don't want to sieze the engine. Start with the basics:

-Oil level

-Leaks under the car or on the engine

-Transmission level

-Coolant

What does the owner's manual say? If you don't have one, you can get one online

Books for cars or other places like this. Chiltons also has a good repair book you can check out. My Chiltons is 1970-1977, and it shows the later Cadillac models like yours as having a lot of electronic controls like an Electronic Control Unit for metering fuel and air; and temperature and evaporation control unit; exhaust gas recirc; early fuel evaporation; etc.

[Guest BJM]

Well Tom, make sure it is the Check Engine light and then check your owners manual to verify that a particular image means what it means. By that I simply means that in in 1981 they DID have catalytic converters and computer engine management but it was very crude.

Basically for most of the 1980's if a check engine light comes on, it means a monitoring part FAILURE. For instance, if a diagnostic code can be found by a mechanic and it refers to the oxygen sensor or the choke control device, then more then likely - replace the part. Unless you see obvious frayed wiring.

In 1981 there were just very basic monitoring devices like the oxygens sensor, some EGR monitors, etc. The other poster might be very right, your check engine light may refer to a fluid level. 1st check your owners manual.

[ThomasBorchers]

Hello you two and thank you very much for your information !

We have just a very small owners manual with no information about the "check engine" light.

Could somebody tell me which carb. was installed at the 1981 Fleetwood 6.0 L engine ( it should be a L62 Engine ) when the car left the factory ? I think it was a Quadrajet but I am not sure.

We are thinking about to change the carb to an Edelbrock because after some years of searching, changing parts we can find out why the engine will not run correct. At idle it runs ok but if we accelerate, the engine runs too rich. If we disconnect the lambda feeler it runs too lean. Seems to be an electronic problem that we can't find and no one can help us with this here.

Regards

Tom

[jaxops]

My 56 had a similar problem, and it turned out to be a huge vacuum leak and I had the dwell set too high. They had a wide range for dwell then so I put it at my 70 Buick's range...wrong! Anyway, something to think about. See if you can computer-search the specs on the car. There are some good sites with Caddy info out there. How Stuff Works: 1981 Cadillac "Displacing 6.0 liters (368 cubic inches) and tuned for a modest 140 horsepower, the Cadillac V-8-6-4 arrived as optional on the 1981 Cadillac Seville and was standard in the balance of the 1981 Cadillac lineup (replacing Cadillac's conventional 425-cubic-inch V-8).

The heart of the V-8-6-4 was an electromechanical system, developed by the Eaton Corporation, that opened and closed the valves on two or four cylinders (hence the name) when signaled by an electronic module controlling the engine's digital fuel injection.

The aim, of course, was improved economy. This was to be accomplished via the cylinders shutting down under part-throttle, low-load conditions when the car didn't need all eight, such as in medium-speed highway cruising. It was a good idea, but too complex and undependable, and Cadillac paid a big price in both image and dollars once angry consumers began suing for redress.

Few mourned when the V-8-6-4 was terminated after just one year, though persisted in Cadillac limousines through 1982. (Ironically, GM revived the idea in the early 2000s -- though not for Cadillacs -- as "Active Fuel Management," which interim technical advances made utterly reliable and virtually invisible to the driver.)Fuel economy also figured in the decision to offer a V-6 engine for the 1981 Cadillac lineup. It was the first time Cadillac had offered a six since well before World War II. This one was a 125-horsepower 4.1-liter unit, basically an enlarged version of Buick's 3.8-liter overhead-valve design and supplied by that sister GM division. The V-6 was optional across the 1981 Cadillac line, limos excepted. Another new extra for the 1981 Cadillac line was an electronic "memory" power seat that assumed one of two preset positions at the touch of a button.In 1982, Cadillac introduced the smallest model in its history. Read more about this humble addition on the next page."

Car Spec Directory: 1981 Cadillac

Cadillac History

Rochester carb Manual, 1981 Cadillac

Hope this helps!

[ThomasBorchers]

Hello,

thank you very much, very interesting.

Kind regards

Tom