1999 pontiac sunfire 2.2 - engine idles fine, engine accellerates fine untill 3,500 rpm then rpm drops to around 3,000 or so then surges back to 3,500. i hold the throttel steady as this is happening. i've replaced the fuel filter thinking maybe clogged filter due to my son possibly running out of gas.

SOURCE: 1999 pontiac sunfire will not start

Maybe the starter is not notify to the engine.

SOURCE: 1998 Pontiac Sunfire won't accelerate

I assume that you do not have a "check engine" light?

The next thing I would do is check the pressure from the fuel pump. You can have this done at your preferred garage, or by purchasing a fuel pressure gauge from any parts store.

Vent the fuel tank vapors by loosening the fuel cap. Remove the electric fuel pump fuse and start the engine. Allow the engine to run until it runs out of fuel and stalls. After spinning the engine over for a period of 3 to 5 seconds, turn off the ignition switch and install the electric fuel pump fuse. Next, install a fuel pressure gauge in the fuel rail supply line, and secure the fuel tank cap. With the ignition key in the on position, verify that no leaks are present and start the engine. Visually verify the PSI reading on the gauge. The pressure for your vehicle should be 41-47 PSI (Pounds per Square Inch). Hope this helps and good luck!

Marvin

• 85242 Answers
• Posted on Mar 30, 2009

SOURCE: car starts run's 3 seconds shuts down

Your car is equipped with a system called PASSKEY standard on all GM cars and light trucks, try the following procedure to reset the system, the battery being dead will trigger the system.

PASSKEY LOCKOUT RESET GM CARS 1999 UP
1) Put the key in the ignition and turn to the "ON" position. Leave it that way for 10 minutes. After 10 minutes turn the key and take it out. Repeat this process (2) more times (3 times, 30 minutes total) This should reset the passlock system to recognize your key.

SOURCE: Hesitation and slight rpm drop at idle and while driving.

it is possible there is a soft vacuum line. try looking behind the maf sensor [attached to the air filter box] on the right side near the plenom next to a blue connector. it's a small piece of hose that is looped from one vacuum circuit to another. I have found them to get very soft and **** air.

Testimonial: "The problem seems to be less consistent now. Guessing maybe there is still a vacuum leak somewhere else. Thanks for the tip :)"

SOURCE: Engine oil type and capacity for 1999 Pontiac Sunfire SE

kinda of oil,, should be on oil cap,,5-20 or 5-30,,10-30,,oil with out filter change,,4qts,,with filter 4.5qts,,that mean four & a half quarts only,,always ck ur oil stick for oil level,,