Problem Details:

My 1997 Pontiac Sunfire will turn on but I need to leave it cranking for a bit and give it a little gas, it can run, but when I try to accelerate past 40mph, the revolutions drop which reduce my speed, so I can't get past 40mph. Also when I am parked and the car is on I can smell gas. Check engine is on. While I am accelerating towards 40mph it feels like it wants to accelerate faster but it wont do it, it accelerates slowly. If I "floor it" i hear weird sounds like glup glup glup, and if i do it too much and stop the car, it will stall.

Car Specifications:

1997 Pontiac Sunfire

Automatic Transmission

4 cylinders


I replaced the following:

Spark plugs

Spark plug wireset

Mass airflow sensor

Throttle position sensor

I added the following:

transmission fluid

Extra Information:

I was told by autozone it could be the throttle control solenoid, idle air control valve, or that it needs a cleansing of the throttle body.

BTW when I try to use a computer to read what is going on, I can't get anything but that hasn't stopped me from driving past 70mph on the highway before this problem. What else could it be?

  • Welcome to Motor Vehicle Maintenance & Repair! Have you tried multiple code readers to see if that is the issue reading it? Have you eliminated the catalytic converter? Will it rev up in neutral? If so, how far? I think without knowing the codes, you're just going to be shooting in the dark. Commented Mar 21, 2018 at 23:13
  • I tried a OBD2 bluetooth thing to read what problem its having but that doesnt seem to work. The car will rev up to 3000rpm on neutral. I did not remove the catalytic converter. Commented Mar 21, 2018 at 23:28
  • Sounds like autozone is trying to sell you stuff. Whats a throttle control solenoid? None of the things they suggested would cause the symptoms. Maybe the third but only if the plate was blocked. Have them pull the codes if your reader isn’t working. Don’t let them sell you anything you don’t know you need. You may be able to flash the codes through the dlc or if it still has one the aldl.
    – Ben
    Commented Mar 22, 2018 at 1:38

1 Answer 1


I am unfamiliar with that particular car, and without additional information, it's only speculation. And in my experience, the older ODBII cars were still a little primitive on being able to pull good, relevant codes for ever sensor. But, it is obviously flooding while you're driving, and a throttle control solenoid could definitely cause this situation. It is designed to help with throttle adjustment while driving, as When the engine is under a strain or load. If it is damaged, it can send innacurate readings to the ECM, allowing more fuel into the motor than air, resulting in a rich condition. You say you can't get past 40mph and that it doesn't accelerate quickly enough. What happens if you floor it from a rolling start? Do the RPMs still drop and/or does it still seem to hesitate?

An IAC (Idle Air Control Valve) is typically more for just that, idle. So unless it is idling erratically, I wouldn't be so sure to throw that part at it just yet. However, a bad IAC can contribute to the longer cranking time.

Even with a really ugly throttle body, I haven't personally seen a vehicle act that way. Of course, cleaning the throttle body is a free and easy thing to do anyway, but I wouldn't bank on that being the sole problem.

I've seen clogged catalytic converters get red hot. When theyre bad, they will definitely stifle your engine under load. Go feel your exhaust after it is warmed up and see if it is overly hot. I've even seen the exhaust gas get so hot, it has melted the rear bumper.

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