Cadillac Repair: 1984 deville stalling, gray court sc, jim speed

Question
QUESTION: Hello,

  First, THANK YOU for any help you can give me. My son has an 84 Deville (old sled). He just replaced wires and plugs because it was running badly. It starts but smells like its running very rich and stalls when put into drive. It seems to idle just fine which leads me to believe there is a bad vacuum line somewhere or a bad sensor? Again, Thank you for any help!~

Jim Speed
Gray Court, SC

ANSWER: IS or HAS the check engine light ever illuminated while driving the vehicle ?.

Does the check engine light illuminate when the ignition switch is in the ON position and the engine OFF ?.


---------- FOLLOW-UP ----------

QUESTION: He tells me that the Check engine light is always on. As far as when the key is in ignition in on position and engine off - yes its on. But, he says sometimes it does turn off when he has managed to start the car previously but then comes back on again.

Thank YOU!

Jim S.

ANSWER: Perform this test:

1. Ignition switch ON. Engine OFF.

2. Simultaneously push and hold the OFF and WARMER buttons on your climate control panel for 3 seconds and release them.

3. Codes will appear and then stop at .7.0

4. Tell me EXACTLY what you see on the display EXACTLY as the codes display.

5. When it gets to .7.0 turn OFF the ignition.

---------- FOLLOW-UP ----------

QUESTION: Hi,

  Tavis got out and did the test you told us to do. He got these results.

The code 4.8.8 came up then 13,16,19,34,44,52

they repeated a few times.

Thanks again!

Jim

Answer
The FIRST thing you want to do is replace the oxygen sensor and CLEAR all the codes from the computer and drive the car and see if any codes return.

To clear the codes:

1. Re-enter diagnostics and after the codes appear you will see .7.0

2. Simultaneously push and hold the OFF and HI (^) buttons on your climate control panel until you see E.0.0 and release the buttons.

3. Turn OFF the ignition key and wait 30 seconds and then start the engine and drive it for a 1/2 or so and see if the check engine light illuminates. If it does re-check for CODES and let me know what codes you get this time.