Surging engine?

Maintenance/Repairs
1

I drive a 1991 Chevy Cavalier. On some mornings when I’m heading to work and get stopped at a traffic light, the engine surges – the tachometer jumps and falls back and I can hear the engine surging and relaxing. I recently drove the car on the highway, and after about 15 miles it started to do the same thing from time to time when I was going at speeds of greater than 60 mph. I made it to my destination and home and now that I’m driving around town, it seems to be fine again. Any idea what’s happening…and whether it’s worth getting an 18 year old car with this problem repaired? Thanks for any insight you can offer!

2

Here are a few suggestions:

  1. Intake air (vacuum) leak
  2. faulty fuel pump
  3. Idle Air Control system faulty
  4. Possible emissions system faulty

Also, a loose or broken TPS (Throttle Position Sensor) can cause surging too.
Check the wiring for corrosion and tightness.

3

Thanks so much for the leads – we’ll start with these!

4

hay not sure if it has one but try the knock senstor not sure if it spelt like that but yer try that

5

Thanks for this – it will be worth a try!

I really appreciate that you took the time to reply as well.

Hopefully it will be one of these things…