1998 Cadillac SLS DTC P0303, P0101, P0103

Your advice is very helpful because I need to plan what to do before taking off the engine cover and it all made alot of sense.

If there was a problem with the fuel pressure regulator wouldn't that set a P0300 and not just a P0303, because the fuel pressure regulator regulates the fuel pressure equally to all of the 8 fuel injectors, so why would it only affect cylinder #3?

The fpr test is done with the engine running, and there should be no sign of fuel anywhere in or at the end of the fpr vacuum line when it is removed, right?

With the engine running and the fpr vacuum line removed, what happens to the fuel delivery as long as the line is off. Will the car stall as soon as the line is removed or just run rough?

With the carburator spray vacuum leak testing, would the idle rise or lower if a leak pulls in the spray, and is the idle changing because the spray temporarily stops the extra air from getting in to the intake or because of the carburator spray going into the the leak area and then into the intake and mixing with the air and gas?

Wy did the battery discharge overnight down to 10 volts if it says in the owners manual that the battery would shut down after 10 minutes to prevent a battery discharge if the lights were left on. Could it be that someone had left the out door lights on and that thery are not covered in the battery shutoff system, that only the interior lights are covered in the automatic battery shutdown system? I asked the person who drovew the car the day before and they couldn't answer whether they had left the lights on the night before. When I got in the car and there was no electric power I might have shut off the sliding interior light switch
which might have been all the way to the right which the always on position.

Was any kind of electrical damage done by the following incident.

After adding 2 quarts of oil the car was driven normaly the next day for local trips.

Then the next day after that I tried to start the car but the battery was down to 10 volts or less with no power available for any of the interior or outside lights.

The owners manual said that there is an automatic battery shut off after 10 minutes for the interior light in case it's left on. I tried to charge the battery with 10 amps at the proper + and - connectors under the hood but the battery chargers needle would go haywire (as soon as I connected the battery chargers - connector to the -bolt terminal ) and all the way to the right as if the terminals were connected backwards? But they weren't. It ook a long time to undo the situation by making a better contact at the - bolt terminal and finally the battery chargers guage needle slowly went towards the middle of its guage reading and started to charge the system. After 30-45 minutes of charging the car was finally able to start. I never figured out how the battery got so discharged and it hasn't happened again.

This is the part I am concerned about.
When I first hooked up the battery charger it was taking a charge and the battery charger guage needle was in the middle indicating a battery that needed a half hour 10 amp charge to get the car started. So I sat in the car while the battery was charging at 10 amps.

After a while the lights were working again, so I turned on the key to check the battery volts info.
With the key on the A/C kept turning on by itself and I kept shutting it off because it had never done that before. There was also a strange sound coming from the upper left of the dashboard that sounded like an intercom and there was a staticy intercom kind of bell/buzz sound that I've never heard before. Every time that I turned off the key and then turned the key on the A/C would turn on to auto A/C. Thats not supposed to happen.

So after a while I went to check the battery charger and it was running, it was on and the guages needle was all the way to the right instead of in the middle or towards the left. That's what usually happens if you touch the 2 battery charger terminal clips together, causing a big spark, and then the charger will shut down. If the battery
charger is plugged into ac and the fuse shuts down
the charger the guage needle will go all the way to the left. So the charger was on and acting as if the 2 terminal clips were touching, but the battery chargers fuse was not turning off the battery charger. This battery charger shutdown will happen if the clips are not quickly seperated after they are touching and sparking.

There was power to the car for the lights, air, etc with the faulty battery charger guage reading connected to the + and - bolts.
When I removed the faulty battery charger hookup there was no more power to the car at all. So all that time the battery had not been charging with the faulty charger hookup but there was power for the lights, air, etc during trhat time.

So the battery chargers terminal clips were hooked up to the cars + and - jumper connections correctly, but the battery chargers guage needle was incorrectly all the way to the right as if the 2 battery charger terminal clips were touching, but the battery charger was continuing to run for a while instead of shutting down like it normally would.

This was happening while I sat in the car waiting for the battery to charge, after I had first hooked it up and the battery chargers guage needle was where it was siupposed to be, in the middle of the guage.

I then kept unhooking and hooking up the battery charger terminal clips to the same + and - jumper termninals trying to get a proper reading from the battery chargers guage which would be towards the middle of the guage. I tried many times, but everytime there would be a big spark at the - jumper bolt and the battery chargers guage needle
would go super fast all the way to the right.

I kept unhooking and trying again. Then I gave up and was sure that the car was now disabled with some kind of shorted out wiring or electrical component.

I got out the owners manual and was reading alot. I checked out as many fuses as I could and they were all ok.

Because this all didn't make sense, I kept trying to hook up the battery chargers clips to the + and - jumper bolts. The - bolt was sparking alot and the needle was all the way to the right. Then I started to grind the - terminal clip all around the - bolt and after a while the battery chargers guage needle slowly climbed to the middle of the guage and then it sdtarted to charge the battery and the car started 30-45 minutes later. The battery has since not discharged.

Why did the battery discharge down to 10 or less volts overnght even if the lights were left on if there
is a discharge battery save system.

Why did the battery charger do all of that faulty hookup and guage readings without shutting down for 15 minutes? What was that strange intercom sound coming from the upper left side of the dashboard and why was the auto A/C turning on all by itself everytime the key was turned on during the faulty battery charger hookup.

I only realized yesterday that the strange symptoms of the auto A/C coming on by itself everytime the key was turned on and that strange intercom sound from the upper left dash, which I've never heard before in this car was becuse of that faulty battery charger hookup. After the car was charged normally those 2 symptoms went away.

But there is this clicking sound that has started from the right side of the dash or from the right door or right side rear view mirror and it continues to make this clicking sound.

What damage if any could that 15 minute or more faulty battery charger hookup to the jumper bolts have done to any part of the electrical system.

Could it have damaged the MAF sensor or the electrical connection to any of the fuel injectors or to the pcm etc, etc. I read those codes a week after the battery needed charging.

Could this charging incident have brought on the conditions that then set off the 3 codes?

Could there be damage to anything electrical after that faulty charger hookup with the needle all the way to the right with the charger continuing to run and the fuse not shutting the charger down the
whole time?

What caused the battery charger to not just be able to charge the battery at the + and - jumper terminaals succesfully, right from the start?

Did this happen because the battery was in shutdown mode when I tried to charge the battery.
If yes, what was the right way to go about reactivating the battery and then rechargeing
it, and why did the system act or react this way to a
simple battery charger hookup that was hooked up correctly?

Is the electrical system protected from this kind of faulty battery charger hookup?

With the faulty battery charger hookup and/or the charger guage reading described above and the charger running all that time, was the battery charger sending a 10 amp electrical current to places where it normally wouldn't or shouldn't, because of the battery being in shutdown mode and could that have damaged any electrical wires, connections, components, etc?

Be as technical as you want, I just got a pc pda and will soon get an elm 327 scanner to go with it, I will probably get a vacuum guage, and maybe a fuel pressure guage, etc.

Thanks

I just read about the battery discharging and the ECM having to relearn all of its settings.

Could that have changed the ECM adjustment instructions to all engine performance sensors, controls, components, etc, and with that then resulting in incorrect readings back to the ECM, which then set off the 2 MAF codes. Could this have maybe even brought on the pending P0303 because #3 was prone to missfire, but not doing so yet, until the ECM lost all of its optimal settings and that then finnally brought on the #3 mosfire? The 3 codes listed were read days after the cars battery was discharged and recharged.

Here is what the article said:
The ECM found in General Motors cars has the capability to learn or modify it's programming with regard to differing fuel requirements over time. Its a complex computer and it can adjust to different conditions easily. It learns while you drive and doesn't forget when you turn your car off either.

But, if you ever change your battery, or your battery goes dead for any reason, your computer will lose it's stored memory and will have to relearn everything. It's a quick learner, but it's something
you don't really want to go through all the time.

Since the battery was totally discharged, could it have anything to do with the codes being set off because of it's affect on the ECM losing all of it's settings? How long does it take for the ECM to recover from the battery discharge? What are the actual affects this has on the cars performance or on any part of the car.

Are the ECM and the PCM the same thing?

How can I test if there was any damage to the ECM or PCM, or anywhere else from that shorted battery charge attempt that you helped me out on?

What would be the best or max size CCA battery to replace the battery for the best performance.
Since its under the seat, there may be a certan max WxDxH battery size. Does it have to be side terminals?

Has AC Delco fixed that problem with their newer side terminal batteries? Does it have to be an AC Delco battery or just any good brand.

Thanks

Are those kind of batteries common for late model cars? What % more would it cost than a regular or non vent set up battery.

The dash voltage reader has always read around 13.9 - 14.2 volts with the engine running with lights, radio, and A/C on, and still does give those same readings.

The dash info battery voltage reading after driving with all the accesories on, with the key on/engine off, is 12.0 volts, and I'm not sure if it was always that low. The car starts ok at 12.0 volts.

I've always only checked the dash info battery voltage with the car running because there never was a problem starting this car.

A few months ago after driving around locally, with all accesories on, I shut off the car and was working on something, for around 15-30 minutes with the headlights on, I am not sure if the domelight was on. After that the car wouldn't start. I Had to get a jump, and it started right up after 5 minutes with another car charging it. I didn't keep track of the battery voltage readings at that time.

Does a dash info battery voltage reading of 12.0 after driving with all the accesories on, key on/engine off, show that the battery is ok, or charging ok, or is that sort of low? How can I test if the battery is still ok, or should be replaced,
besides checking out the physical condition of the battery and the cables.

You had mentioned that a battery could be shorted internally. Can that be ruled out if the car starts and runs ok, with all of the accesories on, or can that condition be intermittent, and only show symptoms once in a while? Can a battery have an intermittent partial short?