Engine rpm erratic and shutting off while driving

Yes, it sounds like you have an intermittent short circuit in your battery or positive battery cable.

Can you try this test and let me know?

https://www.2carpros.com/articles/car-battery-load-test

Please let us know what happens.

Cheers, Ken

car starts most of the time cold, then stalls after a few minutes. I have replaced the fuel pump & fuel regulator, bot the problem still is there. It starts to run really bad just before stalling & I noticed that the exhaust is red hot just after the CAT.

This sounds like a fuel pump or the crankshaft angle sensor has gone out. When you turn the key to the on position without cranking the engine over can you hear the fuel pump run in the tank for 5 seconds?

https://www.2carpros.com/articles/car-cranks-but-wont-start

and

https://www.2carpros.com/articles/engine-stalls

Please run down this guide and report back.

there is no engine light on, I plugged a scanner into it and it said there were no codes, the live feedback while it was running said everything was ok. I can smell fuel and see black smoke out the tail pipe when i rev it,the fuel pressure is 44- 50 psi. I took off the cat but cannot look into it because of the curves in the pipe, the rear o2 sensor is white, the front o2 sensor in the exhaust manifold is black with suit. the car seems to be running rich and I suspected that was why the pipe on the rear of the cat got red hot, if the cat was plugged would the back pipe get hot? could I have a bad o2 sensor w\out a service light? when I had the cat off I tapped it on the ground and only got a little bit of gray powder.

well according to what your saying fuel is dumping into the system and unburned, I suspect a leaking injector or injectors,

I have checked all the injectors and found a shorted one on #3 I got a new one all fixed:)

Glad you could get it fixed, that kind of problem can be tough. Please use 2CarPros anytime we are here to help.

Hi I swapped my 3.8l motor for a 3.8l supercharged motor. The car will shut off while driving. The gas gauge doesn't work anymore. It will read full for about 10 sec then read empty. I replaced the sending unit/fuel pump, gas lines, Mass air flow sensor, and throttle position sensor. I get a p0101 code was talks about my MAF. Please help.

if you put a supercharged motor in it you need to update the computer to same . check the following items in pic but a pro should do some of them. also check to make sure duct work form maf to throttle body has no holes in it or is installed correctly

I did have my computer reflashed. I will get the stuff in the pic checked. Thanks

I changed the ignition cylinder lock. Programmed new keys next day had to reprogram keys again. A week later as I was driving all lights on instrument panel started going out then it just shut off. The trunk push button doesn't work anymore and the new keys don't work so I have to use old ones. I bought this car from someone and don't know what else us going on.

Hello my name is Dave.

According to the manufacturer's instructions there is no need to do any reprogramming when changing the lock cylinder as all the electronic coded components are located in the cylinder housing.Have you checked for any trouble codes? If you haven't I would recommend checking for them.

Here is a link to our tutorial on how to check for trouble codes:

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

In case there are no codes I am pasting a copy of the relearn procedure for the security system and would try that in case something went wrong when it was last performed.

30 MINUTE LEARN PROCEDURE

TOOLS REQUIRED
None

1. Turn ON the ignition, with the engine OFF.

2. Attempt to start the engine, then release the key to ON (vehicle will not start).

3. Observe the SECURITY telltale, after approximately 10 minutes the telltale will turn OFF.

4. Turn OFF the ignition, and wait 5 seconds.

5. Repeat steps 1 through 4 two more times for a total of 3 cycles/30 minutes (the vehicle is now ready to relearn the Passlock Sensor Data Code and/or passwords on the next ignition switch transition from OFF to CRANK).

IMPORTANT: The vehicle learns the Passlock Sensor Data Code and/or password on the next ignition switch transition from OFF to CRANK. You must turn the ignition OFF before attempting to start the vehicle.

6. Start the engine (the vehicle has now learned the Passlock Sensor Data Code and/or password).

7. With a scan tool, clear any DTCs if needed (history DTCs will self clear after 100 ignition cycles).
Please keep us up to date on your progress and thank you for using 2CarPros!

my car shut off for no reason ive had 4 mechanics look at it and no luck they told me it was the fuel pump then the mass air flow sensor then a throttle body position sensor then the spark plugs. ive even took it to the chevy dealer and they told me vaccum leaks please help me.

give me a list of what was done.

give me any codes as well

Roy

what was done new fuel pump new mass air flow sensor new throttle body position sensor new spark plugs and there are no codes when they diagnose it

when does it cut off??

Roy

whenever i can be going 60 and it shuts off or i can be going 20 and it shuts off

does it start right back up??

Roy

no the only way i can get it to start back up is either wait 4 hours or spray some starter fluid in the filter like toward the throttle body. and i dont want to keep doing that because im pretty sure it will mess up the car even more

then it is fuel delivery issue.

if the fuel pressure is correct, something in the injector area may be the culprit

Roy

so maybe it could be the fuel pump again because the fuel pump i got my dad got it from the junk yard

bad move, never, never use used parts in critical systems as this,

start with a new one

Roy

I’m having the same Problem what is this that broken off

That is a breather tube.

Feel free to start a new question and we will be glad to help you.

Roy

I have a 2003 Impala. it started to "stutter" when it was shifting gears automatically a few months ago but only very sporadically. If you stopped and turned the car off for 10 seconds it would start back up with no problems thereafter. a few days ago it would start right up but when put in gear dies immediately. After a good many tries, it made it to the neighbors house roughly about 1/4 mile away without anymore problems. on my return trip it died half way back and wouldn't stay "on" no matter what I did. The next day my husband went to check it out and it started & drove without any problems. He changed the fuel filter and checked gauges, etc but it seemed to work fine for him. However the next day it left me on the side of the road again after going 1/2 mile away from home! It seems to only go 1/2 mile at best before it warms up and then dies and presents the same problem again. It starts fine but doesn't want to idle at all. the only way to get it going now is to put in neutral, start car with gas & brake pressed at the same time. Is my car possessed? what could be wrong?
thanks!

You might be losing the fuel pump. It's a high pressure system, you have high mileage and it is a common problem. Check the fault codes with an engine scanner. It should show something. If not it may have a bad fuel pump. I just hope this helps. ok