Loss of power and only 12 mpg?
 

Hi out there
Would anyone know off the top of tier heads what would cause an 81 Caddy to have loss of power (no get and go) and fuel milage so bad it would be cheaper to drive a kenworth?
the check engine light comes on on occasion not always (I don't know how to get the codes) and the valve train does have some noise in it.
If you have any ideas it would greatly help thanks.
Rob N

RE: Loss of power and only 12 mpg?
 

No missing? just lack of power ? timing?

Pull the codes and we can make an assesment.

RE: Loss of power and only 12 mpg?
 

I'm not sure how to pull the codes for this car, it was a birthday gift to me from my inlaws.

RE: Loss of power and only 12 mpg?
 

Hey runtime; Turn ignition on, motor off, go to the CCC and push off and warmer at the same time and hold untill 88 comes up and then let go of buttons. The codes will come up in numerical sequence like 27 30 38 then it will repeat them and go back to 70. write the codes down and get back to us. Sounds like TPS and the ECM are not relaying info. to each other.

RE: Loss of power and only 12 mpg?
 

This is an 81. I think you have to ground 2 pins in the ALDL connector and count the light blinks. This person needs either a factory service manual or at the least a Haynes manual to proceed.

RE: Loss of power and only 12 mpg?
 

THANK YOU
Ok got the codes the numbers are 24, 30, 45, and 88 came up again at the end not sure if it was supposed to or not.

RE: Loss of power and only 12 mpg?
 

O.K. here we go, code 24 is the speed sensor cuircuit, possible failure. Code 30 is the Idle Speed Control cuircuit. Code 45 is the O2 sensor is rich. 45 is most likely a bad O2 sensor and they are easy to change. If you want to do it yourself you will need an O2 sensor socket to do the job. The socket is about $12 and it has a side cut out of it to accomodate the sensor wires so they are not damaged. Before doing the job just check all the wires and make sure the connections are good and the wires are sound and not broken or cracked. There is a possiblility that with these kind of problems that the ECM may be at fault. That was the case on my 81 and a reman unit was around $170. For the code 30 there is a sequence of test to determine if the ISC is functioning properly so let me know if you intend to try the work yourself , have been over this many times on mine. Code 24 could be a number of things too, defective speed sensor, defective buffer amplifier, defective wires or terminals, ECM not processing siganl, a speedo not functioning. Many diagnostic steps on this one too. Good luck and keep us posted.