1998 Prizm jerking during constant speed?

1998 Chevy Prizm, auto transmission, 77,000 miles.

When driving at about 35-40 miles or about 50 miles in constant speed, I could feel sometimes the car was jerked by something backwards in a very short moment,

then pushed forward immediately for a very short moment

Or it can be described as someone suddenly applied brake then immediately accelerate the car.

Someone explained this is because “transmission slip”, the gear

switched to a lower gear for a short moment and jumped back to

the higher gear.

The other mechanic explained as engine (or one of cylinder ?) died

for a short moment due to spark plug or spark plug wire.

Also, some people suggested it could be 'torque converter clutch' (TCC) which is is supposed to lock up the converter.

If it was erratic, it seems like it could cause these symptoms.

I changed spark plug and transmission fluid & filter, but the symptom still there.

I would like to know what may cause the problem

Update:

Yes, check engine listh were on several times recently. Today I got Autozone scan it for me:

throttle position sensor (TPS) malfunction,

if that is the cause, I would be relief ...

instead of those expensive engine or tranny service

7 Answers

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  • Anonymous
    1 decade ago
    Favorite Answer

    From least expensive to most expensive:

    1. Water in your fuel due to condensation of water in your gas tank, due to the temp changes back and forth in winter. Does your car sit for a couple of days before you drive it the next time ? Put in a container of "HEET" to get the water out of the fuel system (it's really cheap) and keep your tank full of gas all winter long.

    2. Fuel filter needs replacing; it gets clogged with buildup of various fuel residue.

    3. Transmission needs servicing, are you following the recommended service dates on that. If fluid is old, it gets to be like sludge, or if the level is low, the transmission doesn't shift like it should.

    4. Spark plugs AND wires need replacing. (BTW you have either 4 or 6 spark plugs to change, not just one). It may not solve the problem if you only change a plug and not the wire. This would seem rare for a car with 77k on it but sometimes a wire is near the engine and breaks down quicker.

    5. The "emission control" module/fuel monitoring system, the computer that monitors fuel flow and tells the engine and transmission what to do, during different engine speeds , may need to be replaced.

    4. The transmission is due for overhaul.

  • 1 decade ago

    MOst likely it is just the transmission toggling between gears at that certain speed where the car can't decide if second or third or third or overdrive is the best gear to be in. I would pretty much rule ou tthe momentary misfire issue. You usually won't feel it as much as you are describing it. Besides your computer woul have a stored misfire code in it if that were the case. At the same time if you have a TCC (torque converter clutch) issue there should be a stored code for that issue. It is not impossible that you could e having actual transmission problems but I think you would not notice the issue anymore if you just used a little more or a little less throttle at the speeds of concern and made the transmission choose either the higher or the lower gear.

    In other words it sounds to me like the tranny is just in between shifts when you feel that. But you may still want to hook up a scan tool and see if you have any history codes that suggest transmission issues.

    Source(s): General Motors Area Service Manager
  • 1 decade ago

    Has the onboard computer been checked for errors? That might get you closer to an answer.

    If I had to take a guess, I'd say....

    Transmission.

    If it only does this at high speeds, on the road, it'd seem to be gear specific. Misfires would happen at any throttle/gear combo.

    But check the computer for codes.

  • 1 decade ago

    Sounds like the engine is suffering from Missfire on one cylinder.

    Did you change the plug leads and fuel filter.

    Follow with an injector clean, and if you know how, clean the throttle body.

    This is certainly the cheapest place to start.

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  • dusik
    Lv 4
    4 years ago

    Chevy Prizm IS a Toyota Corolla with a Chevy badge. in fact, they're the two outfitted in Fremont, CA on the comparable line. besides the fact that, you will desire to nevertheless inspect the motor vehicle intimately. only "say" this is particularly a Toyota would not inform you what is the subject of that particular motor vehicle.

  • 1 decade ago

    Check fuel filter!

  • Anonymous
    1 decade ago

    the brakes!

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