My car is acting up can you help me?

Question

When I am sitting at a stop light it idels low, then high, then stalls. But it only does it very randomly... It helps when I put it in nutrel while at the stoplight. Does anyone know whats wrong... my car is a 1991 mercury topaz lts.

if it is the O2 sensor or something like that is it safe to drive on the highway... should I be worried about breaking down?

Answer 1

Replace PCV valve

Answer 2

I'm not completely sure, but ask a mechanic about your THROTTLE POSITION SENSOR. When this goes bad, vehicles will cycle a high, then low, then high, then low, etc.

This information is from an auto parts salesman with no mechanic's experience- only through info search for the purposes of sale have I concluded this to be a good starting point to remedy the situation.

Answer 3

this sound,s like your idle solenoid switch is going bad,,all this does is control your idle,,when your driving ,,I'm assuming the car is all right,,the only other thing that might even effect it any at all would be the 0-2 sensor,,this can cause erratic idling,at certain time,s,,and even it wont act up all the time,,if you have done any work to it lately,,check and see if you have any vacuum lines off,,this will cause some what of bad idle,,if all this fail,s take it to a shop,,and let them diagnose the problem for you,,even auto zone has a free computer scan,,and believe me this can save you some money,,hope this help,s some.

Answer 4

Could be sludged up throttle plate. the symtom is called a rolling idle. remove air snorkle [rubber hose from air cleaner to TB], TB = throttle body. carb cleaner /old tooth brush scrub bore and plate ignore black and yellow tag that said not to. Ford instructors told me so. spray out residue, replace snorkle, w/ throttle partly down, start vec. it will be flooded, release throttle when it fires, then rev a few times . Drive , will have to re-learn to idle right becouse of new reading from TPS [throttle position sensor.] hope that was the problem, it's the cheapest, but Very common on earlier Fords.

Answer 5

Check your Transmission torque Convertor Lock up solenoid 91
topaz's had a solenoid that locked up the Torque Convertor during driving . If it doen's unlock when sitting at a red light the car tends to stall .

Answer 6

Billy TK's response is right on the money. Good job describing the fix. I had an '86 Sable that did the same thing and it was a dirty throttle body.

Answer 7

Take the car to a car repair shop.

Answer 8

your car may need a tune up.. it can be anythign really.. it also that they caps may not be adjusted the igtht way.. not enough gas in the tank.. those are some big reasons. mainly because of a tune up you may need one.

Answer 9

sounds like a problem with the timing

Answer 10

Have it tuned up and be sure to tell them to change the fuel filter(s)