QuestionQUESTION: So, I was reading some of your other questions and answers and my little thingy might be stuck open - the thing with the vapors, I'm sorry, I forgot what it's called. But my car is begining to stall, or at least it feels like it's not getting any fuel and begins to lose momentum often at speeds of up to 50-65 mph! It scares me and I've taken it in and had the fuel filter replaced, the transmission looked at and so now I think it's the fuel pump or line. Any ideas?
ANSWER: Evaporative system problems shouldn't cause any abnormal symptoms other than a check engine lamp or perhaps difficulty fueling the vehicle or starting the vehicle after fueling. Other than that you shouldn't be able to notice any problems.
While I'll agree a faulty fuel pump can cause the vehicle to lack power, there's not enough information in your description for me to determine whether you have an engine performance issue or a transmission problem. Presuming this problem occurs every time you drive the vehicle, a shop competent in driveability diagnosis should be able to determine the cause.
The following information may help me determine what's occurring with your vehicle:
1. Is your check engine lamp coming on?
2. When you depress the accelerator while driving does engine speed (RPM) increase?
3. Is there a correlation between power and depressing the accelerator? If so, does depressing the accelerator result in an increase in power?
4. Presuming you have an automatic transmission, does the vehicle ever act as if it's in neutral (engine revs easily but no power is applied) even though the gearshift is in the "D" position.
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QUESTION: My check engine light has been on for several years. I had it read by different mechanics and the free places several times and every time they said there was nothing wrong. So I finally gave up and just go on the feel of the car.
When I press on the accelerator, the RPM's do not increase.
There is not really a correlations between stepping on the gas and the power of the car...it's as if the gears are slipping (I drive a manual transmission).
Hope these details help you. I actually took it in on Friday and the mechanic drove it around and couldn't find anything wrong. He said it drives great but it doesn't! At least not ALL of the time.
AnswerOkay. So we've definitely got an engine performance issue. The potential problems are still large, though. Could be a misfire, a bad air flow sensor, defective throttle position sensor, etc. The diagnostic trouble codes are the next step. Have the trouble codes read and follow-up with them along with code numbers and the year and model of your vehicle. That'll hopefully help me identify what sort of engine performace issue you're having.
If your check engine lamp is on, there is a problem. Any mechanic that reports to you that there is nothing wrong when your check engine lamp is on is either lying to you or is not qualified to diagnose check engine lamp concerns. Also, be aware that most of the people reading your trouble codes for free are not mechanics and are often not qualified to interpret the codes, let alone determine what's causing them.
As for the mechanic that drove the car around-- I presume the check engine lamp was still on. Did he read the trouble codes? If not, he wasn't making much of an effort to find and repair your problem. If that's the case, you shouldn't continue to take vehicle performance or check engine lamp issues to him. He either doesn't car about repairing your vehicle or isn't properly qualified to do the diagnosis.
