We just picked up a 1985 Cadillac Deville with 42,000 original miles. The car had not been driven in 4 years. It was given a tune up, all liquids were changed. When we changed the gas filter there was some water gave it a treatment with Heet. When you drive and press on the gas pedal it chokes. Could it be some water in the gas or another problem?

Yes, water could be in the gasoline. Try to run a few tanks of gas through it to clear up that problem.

Are there any engine codes on this car that are readable? Maybe a throttle position sensor is not giving good data to the computer.

BASIC TROUBLESHOOTING

1. NOTE: The following explains how to activate the Trouble Code signal light in the instrument cluster. Before suspecting the C-4 or CCC system, or any of its components as being faulty, check the ignition system (distributor, timing, spark plugs and wires). Check the engine compression, the air cleaner and any of the emission control components that are not controlled by the ECM. Also check the intake manifold, the vacuum hoses and hose connectors for any leaks. Check the carburetor mounting bolts for tightness. NOTE: For information regarding computer control/troubleshooting of the Electronic and Digital fuel injected vehicles, please refer to Section 5 of this manual. The following symptoms could indicate a possible problem area with the C-4 or CCC systems:
   1. Detonation
   2. Stalling or rough idling when the engine is cold
   3. Stalling or rough idling when the engine is hot
   4. Missing
   5. Hesitation
   6. Surging
   7. Poor gasoline mileage
   8. Sluggish or spongy performance
   9. Hard starting when engine is cold
   10. Hard starting when the engine is hot
   11. Objectionable exhaust odors
   12. Engine cuts out
   13. Improper idle speed (CCC only). As a bulb and system check, the Check Engine light will come on when the ignition switch is turned to the ON position but the engine is not started. The Check Engine light will also produce the trouble code/codes by a series of flashes which translate as follows: When the diagnostic test lead (C-4) or terminal (CCC) under the instrument panel is grounded, with the ignition in the ON position and the engine not running, the Check Engine light will flash once, pause, and then flash twice in rapid succession. This is a Code 12, which indicates that the diagnostic system is working. After a long pause, the Code 12 will repeat itself two more times. This whole cycle will then repeat itself until the engine is started or the ignition switch is turned OFF. When the engine is started, the Check Engine light will remain on for a few seconds and then turn off. If the Check Engine light remains on, the self-diagnostic system has detected a problem. If the test lead (C-4) or test terminal (CCC) is then grounded, the trouble code will flash (3) three times. If more than one problem is found to be in existence, each trouble code will flash (3) three times and then change to the next one. Trouble codes will flash in numerical order (lowest code number to highest). The trouble code series will repeat themselves for as long as the test leads or terminal remains grounded. A trouble code indicates a problem with a given circuit. For example, trouble code 14 indicates a problem in the cooling sensor circuit. This includes the coolant sensor, its electrical harness and the Electronic Control Module (ECM). Since the self-diagnostic system cannot diagnose every possible fault in the system, the absence of a trouble code does not necessarily mean that the system is trouble-free. To determine whether or not a problem with the system exists that does not activate a trouble code, a system performance check must be made. This job should be left to a qualified service technician. In the case of an intermittent fault in the system, the Check Engine light will go out when the fault goes away, but the trouble code will remain in the memory of the ECM. Therefore, if a trouble code can be obtained even though the Check Engine light is not on, it must still be evaluated. It must be determined if the fault is intermittent or if the engine must be operating under certain conditions (acceleration, deceleration, etc.) before the Check Engine light will come on. In some cases, certain trouble codes will not be recorded in the ECM until the engine has been operated at part throttle for at least 5-18 minutes. On the C-4 system, the ECM erases all trouble codes every time that the ignition is turned off. In the case of intermittent faults, a long term memory is desirable. This can be produced by connecting the orange connector/lead from terminal S of the ECM directly to the battery (or a hot fuse panel terminal). This terminal must always be disconnected immediately after diagnosis as it puts an undue strain on the battery. On the CCC system, a trouble code will be stored until the terminal R at the ECM has been disconnected from the battery for at least 10 seconds. Fig. 1: C-4 system diagnostic test lead location - above ECM Fig. 2: Under dash test terminal location
       Fig. 3: CCC system diagnostic test terminal locateWe just picked up a 1985 Cadillac Deville with - 85874041.gif the left side of the instrument panel