Levelers + engine dying

92 PA, 111K miles

OK, I've discovered 2 more problems I'd like some advice on.

Yesterday I drove my wife to a gymnastics meet (she's a coach) about 100 miles from home, no problems at all. But as I was being supportive during the meet (sitting out in the car, reading a book) I noticed something. The air pump, which I assume does ride leveling or something like that, would come on, run for about 10 seconds or so, and cut off. This was happening about every 10 minutes or so, key NOT even in the ignition. Does this indicate something is leaking and needs replacing? If so, how do I figure out what it is? I had not noticed this before, but again I had never just sat in it for long periods with everything off before (I've only had since this May).

Also, my son has been driving the car a good bit, and he kept telling me it would go dead when stopping for some reason. I had not noticed it at all, until this AM, going to church. As I was driving out of my neighborhood, rolling through a stop sign at the bottom of the hill (come on, quiet neighborhood, no cars in sight, you would have done it too), I slowed down enough to make sure nothing coming, then lightly applied gas to make the turn, sure enough, it went dead, no warning. I was able to put it in neutral and recrank, no problem. This is yet another of those things that only happens once in a long while, so it'll be difficult to track down.

Thanks for all advice.

Unfortunately, you have an air leak in the rear strut bladders. You will need to replace the air struts. :crying: Monroe SensaTracs, are the best choice for the Buick.

The RAP module (Retained accessory power) is part of the battery protection circuit and if it is working correctly, it will shut down all power to accessories after 10 minutes, from the time the driver exits the car or when the lock is pressed on the remote. If you are sitting the car reading a book, it should shut down all power (with ignition off) within 10-minutes and you would not have any power to run the air pump or any other accessory. If your compressor was coming on after the 10-minute interval, you may have a RAP module problem. (Very rare) Check this out again, when you have some time on your hands!

The random stalling, points to the code you mentioned in your previous thread about the crank position sensor & cam sensor. Usually, this is the first sign of, crank position sensor failure!:crying:
:sadwavey:

Within 10 minutes after I exit the car... well, I never actually did exit the car, but I did turn it off and pull the key from the ignition. It was definitely firing up the pump after that time.

I did notice that it shut down the radio after a while, so the system is doing something.

Looks like about $80 each for those struts! I haven't read up on it yet, but I assume an alignment would be in order after replacement. More $$.

And I know I need to do something about the crank/cam sensors, just putting it off until I get one of my other cars put back together (89 Civic, new rings/bearings/valve seals). I'll never get finished with these cars! Still cheaper than buying new ones, though.

Within 10 minutes after I exit the car... well, I never actually did exit the car, but I did turn it off and pull the key from the ignition. It was definitely firing up the pump after that time.

I did notice that it shut down the radio after a while, so the system is doing something.

The RAP will time out after the 5-10 min interval, with ignition off while just sitting in the car; the same logic applies to exiting the car and locking the doors. If it did shut down the radio, it would also disable the compressor at the same time. If you sat in the car for more than ten minutes, you should not here the compressor run again, unless you turn the ignition on/off to excite the RAP. If you turn the ignition on/off, you would then have another power-on, 5-10 min timeout. Yes, the pump will come on during the 5-10 min timeout, with ignition off and keys removed! It sounds like that part of the system, is working as intended on your car.:lol:


Also, you will need an alignment after installing struts.:crying:
All this work is, "Still cheaper than buying new ones, though":grinyes:
Good luck!

Before I had my Park Avenue, I had a 95 Roadmaster (I miss that car :crying: ) that had auto-levelers. I had a leak in my system, causing the compressor to cycle on/off every 20 min's or so, even when the car was off. I would work in my garage and hear it kick on for about 4-5 seconds about every 20 min's, even though I had not driven the car since the day before. In working with people on a Roadmaster/ImpalaSS/Caprice/Fleetwood message board (sorry, not on AF :uhoh: ), I was told and read about numerous times that the system was live even when the cars were off. If I remember correctly, I even noticed that in the wiring diagrams in my shop-repair manuals that the power feed to the compressor is hot at all times. Good thing I had a good battery!

I don't know that this would be true for the 92 PA, but I only bring this up to suggest the possibility that dwhisent's car may be set up the same way...and if so, would mean that his RAP module may be ok (considering it appears to be working in other aspects...ie. radio). I realize his may be set up only to run when he has power, either with the key or with RAP. My 01 PA, I have found, is different from my 95 Roadmaster. I brought home bags of sand from Home Depot and really loaded the car down. With my Roadmaster, it would have been leveling the car as I was loading it, but notice that my PA waited until after I started the car and it passed it's "waiting period", then pumped up the rear of the car.

Just a thought.

Yes, that is strange how some GM products may be active all the time! That could be a real problem, if you parked your car for a few weeks with air system leaks! Can you imagine how many times the compressor would cycle on/off during this time and how quickly your battery would die? My 92 PA had strut bladder leaks several years ago and I did have the time to observe the operation of the timers. My ALC, would try to keep the car level after the ignition was turned off and sometimes would cycle again within five minutes, however, after the timeout, it would not cycle again. (The car would just drop in the rear). :disappoin The next time the ignition was turned on, the cycle would start the timers again.

Basically, this is how the system should work;

System activates when ignition is turned on, and will remain active until 6 min after switching ignition off.

Compressor head houses the dump valve. There is an 8-15 second delay in the sensor circuit, to prevent compressor/dump valve operation during normal driving.

Sensor also limits compressor run time/dump valve, cycle to 6-min in the event of severe system leak; turning ignition on & off resets the run time. This has been known to cause the fuse to blow, or the compressor to fail. (Too many run cycles in a short period of time)

An air replenishment cycle is initiated when the ignition is turned on. If the vehicle is a the correct height, a timer starts and after 35-40 seconds, the compressor will run for about 4 seconds to ensure that the shocks are filled with adequate residual pressure.(8-14 psi)

If weight is added to the vehicle during the replenishment cycle, then replenishment is over ridden.

To reduce compressor starting current, the dump valve is opened for 1.5 sec. each time the compressor starts.

After turning on the ignition and allowing the replenishment cycle to complete, add 300 pounds (1,2or3 friends depending on size) to the rear and observe the drop in ride height. After 8-15 seconds you should hear the compressor start (listen closely by the front left fender and you will even hear the 1.5 second dump valve operation). Then with the 300 pounds still in the rear, observe the body trim moving up to the correct ride height. The compressor should then cut off, and your car will stay at the correct height, provided you do not have leaks.

Remove the load (car will rise too high) and listen again near the compressor, after 8-15 seconds, you should hear the air escaping through the dump valve until the car is level.:screwy:

Well, after all this, I had to try it out again. Another gymnastics meet this past Saturday, more waiting in the car reading a book. Here's what I noticed:

Before time for my wife to go in and start coaching, we waited 45 min in the car, and the levelers never kicked on. Started to doubt what I heard the previous Saturday.

I drove around some during the meet, then parked again, turned the car off and took the key out of the ignition, and grabbed my book. The levelers kicked in every 4 minutes! After 10 mins or so, the radio clock went off, but the levelers continued kicking in, again every 4 minutes. I did happen to look up once, and I noticed the courtesy lights came on when the compressor kicked on, then shut off about 10 sec or so after the compressor stopped. So, no, I am not losing my mind (well, maybe I am, but at least I was right about this).

I don't have any battery problems, even after the car not being cranked at all for 6 days, so I assume the levelers are only doing their thing with my weight in the driver's seat (especially since they didn't do it with my wife sitting in the passenger seat).

Anyway, I guess the bottom line is I need to replace them.

I posted a lengthy thread a while back about replacing the rear struts. I pulled out my shoulder when I replaced mine, so be careful to use the right tools and techniques if you plan to do it yourself

Thanks, Diogreer. Good advice. I'll look for your post.