When you yurn it over it does not start but when you let off the key it try to start but dont it swill start sometimes but wont rev up fast it will if you gradually give it gas but if you hit it fast it dies already replaced eletrical part of switch also

no year stated. that is challenging
2 problems.
if it dont start , traction dont matter now so, will the engine crank over fast? if yes, is the spark good? on all cylinders?
yes/no
how many miles on it?
which engine/
2.5 L (156 hp) a V6
2.7 L (185hp) V6

no starts.
Does the Check engine lamp glow key on,
Yes, good
no , fuse blown. (the PCM EFI brain must have power to run)

1. does it crank? fast?
2. check fuses yet. all fuses, related to EFI? and spark.
3. Got spark at all 6? spark plugs. (tedious on C.O.P. cars)
4. if above all ok, we try test fuel to see if you lost fueling.

wont CRANK or CRANKS Fast but will not start , which is it?
the fuses blew or the battery is dead (discharged)
battery voltage is 12.6vdc rested, if not and is lower, its discharged.

did warning lights come on before the STALL? (died is stall)
if yes, and the charge lamp came on, and was ignored this is normal
for the battery to die. with alternator dead.

try jumper cable starts yet? that be next after fuses. and battery volts. (no cranking)
if it cranks fast, still fuses. check. then check for spark if not a diesel. some GV have Diesels, (3 kinds too)

Catch?
cranks fast
starts every time.
idles fine hot or cold , or both? hot idle not too fast.
i race engine , in park and neutral, I can hit 3500 rpm easy, can you.
i release brakes, (brakes are not packed in ICE , are they?)
I select 1gear or reverse (A/T or m/t)
the car moves or dont move, which is it, my guess catch = no move at all.
I try to drive, i look at RPM and MPH
RPM moves up and MPH track.
track means they both move in a linear progression.
RPM rises and for all RPM increases MPH also increases.
does it?
if all that works then we have an engine power issue.
weak on hills?

I had this happen last month. It was my starter. My previous cars would miss and catch, letting me know the starter was finished, but this one just totally died, I had power for lights and gages moved, but would not start.

Do the throttle body cleaning and re- learn idle speed control valve.

well first give both switches a good swilling of switch cleaner or some thing like WD40 then if this dont put it right take off the clutch switch turn on the ignishion and short out the clutch switch if the motor turns over its the clutch switch if it dont its the ignishion switch but i bet a good swilling with WD40 sorts it out first,

Sometimes due to drinking soda or eating behind the wheel might give this problem, make sure you doing right and wheel is clean, connector switch is clean. if still does same thing go to nearest dealer for diagnosis test. Dont forget to check fuses under steering column and seats by the way

Looks like it's sucking air soemwhere. Try using a separate container to **** the diesel and see if there is any difference. Otherwise try leaving the car idling for 10-15 mins as sometimes air trapped in the pump can be very hard to bleed.
Cheers.

Hello, It sounds as if the theft deterrent system is tripped. Look at the key is it worn bad? If so get a new one made at the dealer. To do a key test isert the key, turn to start and release if theft light comes on leave key alone in the on position ten minutes after you try to start never turn off after you yurn to start it puts it in a certain mode, and do not bother it for about 12 minutes. When you come back to car turn switch off then turn to start and it should start thank you.Please rate this answer, thank you.

for the fist little while you can drive 2 footed and the first thing you shuold do for the time being is get some fuel injector cleaner and some high octane gas or some octane booster good luckwith the car