1995 Park Avenue Ultra Idling Low

[GyraFan]

I'm having a strange issue with my '95 Park Avenue where it will routinely idle low when in park, reverse, or neutral. I recently swapped out the battery, alternator, and starter since the old alternator which was in the car was not charging the battery when I drove; I was having low voltage readings, sometimes just a hair above 8 volts, on the dashboard while idling. After replacing the battery, alternator, and starter, the battery now appears to be good when stopped at stop lights or idling in traffic, but once every minute or so, the volt meter will drop. Normally when driving, it sits around 14-15 volts. When idling, it will sit at this point, then momentarily drop down to 11 volts for no more than a few seconds before returning to its previous position of 13-14, sometimes 15. The drop is more noticeable when I have the AC running, turn signal engaged, etc.

I just replaced the alternator again today to see if it was an issue with the internal regulator, but as soon as I started the car, the issue returned. I've already checked all of my battery and alternator connections, all of them are tight and secure. When I was mounting the new alternator, I checked the belt tensioner to see if it was loose, but it seemed to be fairly tight and the belts themselves are taut. When the engine is running and the car has the voltage drop, I don't see any kind of interruption or issue with the belts; they're running the same as when the car is either in recovery from the drop or running normally.

What are some other possible causes for this issue? I've put a ton of time, effort, and money into making this car shipshape and I want to hold onto it as long as I possibly can.

 

[Alan 55]

Welcome to the group! It seems that the low idle issue is a mystery at this point. There are several components that could play a role in this low idle situation. In my opinion three things should be checked out with a scan tool. The throttle position sensor, air idle controller and the coolant temperature sensor. The challenge that you are likely to be facing is an OBD 1.5 system. In 1996 OBD 2 was released for diagnostic testing. In some rare cases some OBD 2 systems were found on late 95 models. Do you know which type you have? OBD 2 has a 16 terminal connection near the steering column.

 

[GyraFan]

Thanks for the quick reply! I checked down near the brake pedal and found a port which looks to have 16 slots. I cannot tell if each slot has a terminal, so I've attached a picture (apologies for the poor quality!)

 

[Alan 55]

Thanks for the quick reply! I checked down near the brake pedal and found a port which looks to have 16 slots. I cannot tell if each slot has a terminal, so I've attached a picture (apologies for the poor quality!)View attachment 18428

That is the 16 pin OBD 2 type connector but am concerned that it may actually be the 1.5 system which is not as easy to work with. The fastest way to find out is to go to an Autozone or other auto parts store that advertises a free check engine test. If they are able to access the computer then it is OBD 2 which is good news. To access the OBD 1 or OBD 2, it takes more of a specialized scan tool and the info is not nearly as detailed. Hope you have a parts store that will take an interest in your situation. If a certain store is no help try another.

 

[GyraFan]

Sounds good, I have a couple near me who should be able to try a scan and see what comes up. I'll post my results tomorrow and let you know what they found.

 

[GyraFan]

Quick update: I found an Autozone near me which was still open so I had them check and the reader kept throwing error codes, so it doesn't appear to be OBD 2.

 

[HotZ28]

You need to have a scan of the system with a capable OBD1/OBD2 scanner! I have never heard, nor seen a '95 PA that was fully OBDII compliant! The first year of OBD2 was 1996.