Feeling defeated.

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Ok, so awhile back my Regal started acting up. Looking online I found these cars where known for electrical problems but the car ran fine and I had no problems at the time. Fast forward now and the cars running a little rough and likes to stall out when coming to a stop or letting off the gas a
That was about 3 months ago. Since then the cruise control, A/C, and passenger window all went out magically on their own while the car was off. Decided not to really worry about it as its more of a back up vehicle. A few days back I thought about getting a scanner that was compatible with the car. Thanks to the help of Clinebarger who helped me figure out exactly which type of connection my obd 1.5 was I decided to go out and purchase a scan tool capable of working with the car (second guesing the shop). I ended up with a Actron CP9690 paid $219 and it arrived this morning I hooked it up. Low and behold it is in fact the TPS. Car's throwing error code P0123 (TP Sensor Circuit High Input Conditions).

I'm at a loss of words really with this car. I've replaced the sensor and the wiring harness. My only guess would be maybe just maybe there is a short leading from the PCM to the actual sensor...

Between the scanner and a few parts I threw at it before hand I'm sitting right about $800 invested into fixing this problem and I'm still at square one.

I guess the good news is that my A/C isn't bad after all the scanner also read a A/C freon low code. Which is good news because with all the problems I had with the car in such a short period of time I hadn't wanted to put any more money into the vehicle as I was kinda expecting electrical and the car does run but it just has loss of power on the high end and the occasional stall at low speeds.
 
What year is this?

Yep, I hate it when I do lots of debug but never get anywhere.

Can the code reader read current sensor value? Is it reading high always, or just out to lunch? Sometimes parts are bad right out of the box (or wrong one altogether), so I wouldn't dismiss the possibility that the TSP (or related wiring) is still bad.
 
Originally Posted By: crazyoildude
What year and does it do it when it is cold?
And exactly what is happening in detail i may have a remedy for you.
Mileage?


Car actually runs fairly fine when cold, no real loss of power and no stalling for sure however I do not gun the car expectially while its cold.

Year is a 1995 Regal limited with the 3.8 and 99.6k original miles.
 
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Originally Posted By: supton
What year is this?

Yep, I hate it when I do lots of debug but never get anywhere.

Can the code reader read current sensor value? Is it reading high always, or just out to lunch? Sometimes parts are bad right out of the box (or wrong one altogether), so I wouldn't dismiss the possibility that the TSP (or related wiring) is still bad.


I dont really know if OBD 1 offered live data but the scanner is capable of live data however im under the impression that is only obd 2
 
Originally the car ran fine and it wasnt until I got about 15 miles away did it act up. Mainly started doing it once it would warm up and the car would almost immediately downshift. If I was to floor the car it would accelerate to a decent level (city driving wise) but on the highway any serious gas to move it would case the car to act bogged down. I've had it happen twice while passing a car and it resulted in the car kicking out of gear until it was restarted then magically went back into gear however i think that is unrelated.

The car ran fairly well while cold all tho it still lost most of its top end performance. Transmission wise the car is in a good state this problem is less then 1k miles old and before hand I never had any problem's with the tranny what so ever.
 
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1998 should be OBDII, not OBDI.

Runs good cold? Sure it's not a temp sensor issue? I'd check to see what the scanner says it thinks the engine temp is. That and O2.
 
Originally Posted By: supton
1998 should be OBDII, not OBDI.

Runs good cold? Sure it's not a temp sensor issue? I'd check to see what the scanner says it thinks the engine temp is. That and O2.


sorry about that its a 95 I actually caught myself typing 98 then went to 1995 but apparently typed 1998. Been a long night day (mainly work graveyard).
 
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Originally Posted By: supton
1998 should be OBDII, not OBDI.

Runs good cold? Sure it's not a temp sensor issue? I'd check to see what the scanner says it thinks the engine temp is. That and O2.
\

That was my first guess. It has been replaced and engine temps rarely creep above 1/2
 
OK, so the car is older and the factory always uses only crimp connected wire lugs. Over time they get crevice corrosion between the metal surfaces. It's like tarnish. Not much, but changes the nature of the wire and creates tiny semi-conductors which drop the voltage a tad here and there.

It's usually not a big deal on the Positive side as there is voltage to "push" the current to the device. But, it is a big deal on the Ground side as there is no real voltage to overcome the resistance. The voltage has been used up by the device like the window motor of whatever. And the same current still has to flow to back to source ...

Any older car that starts acting up is an automatic candidate for a renewed ground path. I take off the Bat Neg (-) cable and examine it from end to end. It's usually nasty and corroded. Same for the Bat Pos (+), but it's usually harder to do because it goes down to the starter. And if they are side terminal cables and battery, that just makes it worse as there is usually and weak connection at the battery.

If the battery is over about 3 years old and it's a side terminal, loose it. Put a fresh top terminal battery in there and change the cables. If you're handy with a soldering iron/torch, clean the ends that go to the engine and solder the lugs to the actual wire. You can usually do this through the bolt hole. Now clean the area around where the Neg (-) cable attaches to the engine and back off and retighten a few nearby bolts. I'd use a dab of Never Seize on the threads when I re-installed them. But any way you can get a new connection will work.

Make up a couple of like #8 stranded wire leads with appropriate solder-on HD lugs to go from the engine under the new Bat Neg cable (or bolts close by) to the fire wall. Usually a hood hinge bolt works well. One on each side. Passenger and Driver.

Betcha lunch that all your issues are now gone and the car idles and drives better along with the dash and interior functions working
smile.gif


The engine computer (ECM) may be trying to read signals that are "floating" without a solid common ground between the body, engine and battery. That will always lead to just what you are describing ...
 
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The scanner can read the cars data (sorry this is new to me) and I watched the temp rise from 93-120 before I looked at other things. The TPS is throwing a vallue of 4.55v constant at idle.
 
Originally Posted By: BrocLuno
OK, so the car is older and the factory always uses only crimp connected wire lugs. Over time they get crevice corrosion between the metal surfaces. It's like tarnish. Not much, but changes the nature of the wire and creates tiny semi-conductors which drop the voltage a tad here and there.

It's usually not a big deal on the Positive side as there is voltage to "push" the current to the device. But, it is a big deal on the Ground side as there is no real voltage to overcome the resistance. The voltage has been used up by the device like the window motor of whatever. And the same current still has to flow to back to source ...

Any older car that starts acting up is an automatic candidate for a renewed ground path. I take off the Bat Neg (-) cable and examine it from end to end. It's usually nasty and corroded. Same for the Bat Pos (+), but it's usually harder to do because it goes down to the starter. And if they are side terminal cables and battery, that just makes it worse as there is usually and weak connection at the battery.

If the battery is over about 3 years old and it's a side terminal, loose it. Put a fresh top terminal battery in there and change the cables. If you're handy with a soldering iron/torch, clean the ends that go to the engine and solder the lugs to the actual wire. You can usually do this through the bolt hole. Now clean the area around where the Neg (-) cable attaches to the engine and back off and retighten a few nearby bolts. I'd use a dab of Never Seize on the threads when I re-installed them. But any way you can get a new connection will work.

Make up a couple of like #8 stranded wire leads with appropriate solder-on HD lugs to go from the engine under the new Bat Neg cable (or bolts close by) to the fire wall. Usually a hood hinge bolt works well. One on each side. Passenger and Driver.

Betcha lunch that all your issues are now gone and the car idles and drives better along with the dash and interior functions working
smile.gif


The engine computer (ECM) may be trying to read signals that are "floating" without a solid common ground between the body, engine and battery. That will always lead to just what you are describing ...


I will definitely give it a shot but it might be later before I can reply. Been up for about 24 hours now and only reason i've gotten this far is because it was on the porch when I got home. I will most definitely do this and let you know!
 
There is a very very good chance it is a bad injector or maybe more than one, very common on those years GM's you can check the injectors with an ohm meter.. When they get really bad in some cases they will shut off the ecm so it wont be overloaded and car won't start until it cools off for a while.
This stumps many people in the business.

Runs great cold then acts up at operating temperature...
 
Check for vacuum leaks. I just went through something similar on daughters camry. I decided to look at the hoses that go to the air cleaner. It has two bellows type hoses, both were cracked on the bottom, letting in air after the MAF sensor. Fouls everything up with the fuel ratios. New air hose, car runs perfectly now. Just as an off chance idea, no scanner finds this type of thing.
 
you need to go back to the basics, spark, fuel, air. while were are spitballing here, my wild guess is lack of fuel pressure. good luck.
 
Originally Posted By: goodtimes
Check for vacuum leaks. I just went through something similar on daughters camry. I decided to look at the hoses that go to the air cleaner. It has two bellows type hoses, both were cracked on the bottom, letting in air after the MAF sensor. Fouls everything up with the fuel ratios. New air hose, car runs perfectly now. Just as an off chance idea, no scanner finds this type of thing.


Already have, in fact I replaced all the vacuum lines.
 
Originally Posted By: cptbarkey
you need to go back to the basics, spark, fuel, air. while were are spitballing here, my wild guess is lack of fuel pressure. good luck.


Originally I was certain it was ignition related. I've replaced most ignition related components except fro the fuel injectors. I've had the fuel pressure tested and the pump seems to be fine.

I've invest close to if not more then $800 trying to fix this.

On a side note the MAF sensor was replaced right before I got the car so it has less then 7k miles on it, vacuum lines have been replaced and it has a new air filter as well. Thats why I'm kinda feeling defeated. I want to fix the car but by this point its becoming a battle. I'm thinking it might be some bad wiring or short.

I am open to all suggestions tho and I do not mean to criticize guess its my fault for not listing everything but I've tried most of the basics before it got to this point.
 
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Originally Posted By: BrocLuno
OK, so the car is older and the factory always uses only crimp connected wire lugs. Over time they get crevice corrosion between the metal surfaces. It's like tarnish. Not much, but changes the nature of the wire and creates tiny semi-conductors which drop the voltage a tad here and there.

It's usually not a big deal on the Positive side as there is voltage to "push" the current to the device. But, it is a big deal on the Ground side as there is no real voltage to overcome the resistance. The voltage has been used up by the device like the window motor of whatever. And the same current still has to flow to back to source ...

Any older car that starts acting up is an automatic candidate for a renewed ground path. I take off the Bat Neg (-) cable and examine it from end to end. It's usually nasty and corroded. Same for the Bat Pos (+), but it's usually harder to do because it goes down to the starter. And if they are side terminal cables and battery, that just makes it worse as there is usually and weak connection at the battery.

If the battery is over about 3 years old and it's a side terminal, loose it. Put a fresh top terminal battery in there and change the cables. If you're handy with a soldering iron/torch, clean the ends that go to the engine and solder the lugs to the actual wire. You can usually do this through the bolt hole. Now clean the area around where the Neg (-) cable attaches to the engine and back off and retighten a few nearby bolts. I'd use a dab of Never Seize on the threads when I re-installed them. But any way you can get a new connection will work.

Make up a couple of like #8 stranded wire leads with appropriate solder-on HD lugs to go from the engine under the new Bat Neg cable (or bolts close by) to the fire wall. Usually a hood hinge bolt works well. One on each side. Passenger and Driver.

Betcha lunch that all your issues are now gone and the car idles and drives better along with the dash and interior functions working
smile.gif


The engine computer (ECM) may be trying to read signals that are "floating" without a solid common ground between the body, engine and battery. That will always lead to just what you are describing ...
Kirchoff's Laws with respect to current and voltage make no reference to voltage "pushing and pulling".
 
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