2000 Impala:Hard start and couple times Idles extremly high

when it does not run check for spark if you have spark check fuel pressure. it as to be one of them for it not to start. I have a 1991 civc with 1.5 4cly doing the same thing. need more information to help more

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/jim_c09d8140f32619a8

try first fuel pressure ck then go to the crank sensor how many km,s does it have ,could have bad fuel change the filter then do the test ther is crank fuse too to ck also ck the coil packs for spark get back too me if ya wood thks again for your time The Farmer

A temp sensor out of range giving a false cold reading can cause high idle . A MAP sensor can also cause high idle by advancing the timing resulting in higher idle .

many possible causes. sounds all too much like a crank sensor failing. when it dies, does it act like you shut key off, (instant stall)? or does it sputter and cough, then stall out? seen this same situation and problem many times in my shop and a cranksensor fail can be hard to catch when it fails. most likely cause.

Check under the hood on the side of the fuel rail, the fuel pressure regulator value, this is a common problem.

Sometimes on cold days if the cranking amps on the battery are low, then it will be hard for the vehicle to start. Also, check the oil level. If the level is low it will create a hard start and rough idle for the vehicle.

check the crank sensor because the computer uses its signal to control fuel and spark

Fooling with the battery cable only fixes the problem because it wastes time while the car is flooded. Instead... pretend like you are fooling with the battery cable and then after a couple minutes, try starting the car again. It will start.

There are many things to check. Most commonly, the crankshaft position sensor. Unfortunately, it's the hardest to replace. It will take about 1 hour to replace if you have the right harmonic balancer puller. Other things to check that are easier...

2 Camshaft position sensor
3 MAF sensor
4 IAC
5 Fuel pressure regulator
6 Vacuum leak

Most of the time this problem is fixed by replacing the Crank sensor, but not always. Lesson learned here... Never buy a GM again.

Luckily your heated seats haven't caught fire and burned your clothing and your back. If it ever does happen... do yourself a favor, let it burn and get a new car (not another GM.)

First thing to do is check under hood for any "hissing" noises, and check all vacuum hoses are connected properly, and not leaking.

check the battery cable connection that is sandwiched between the battery and the outside cable, It runs the computer and if it is corroded, clean it with sandpaper. Mine was loose and corroded and I would stall out of no where.