QuestionWe have a 1993 hyundia excel, 2 dr hatchback, 4 cylinder. The car will run fine then unexpectedly quits running, the check engine light is staying on and it also has a very rough idle when stopped in drive or slowing down to stop. Can you help us?
AnswerIf your check engine lamp is on, the first step is to check the trouble codes. If you've got an analog voltmeter, you can do this yourself.
Go to www.hmaservice.com (requires internet explorer) and register for a free account. Go to the fuel section of the service manual and check the trouble codes by the procedure for manual checking of codes.
Additionally, the self-diagnostic capabilities of this car are minimal. If you can, please answer the following in addition to telling me the trouble code:
1. Is the car misfiring?
2. At what rpm does it idle?
3. Do you feel a jerk like someone hit the rear of your car when you come to a stop?
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In my feedback, you added:
HT, you replied to my ? on the 1993 hyundia. we have tried to check the troublecodes,will not read, just keeps pulsing same pulse. no on the misfiring,it idles at 800 rpm, and yes it feels like someone hit the rear of the car when coming to a stop. Any suggestions would be helpful. And we have taken it to, two different shops for diagnostics to be checked would not read. ECU maybe???
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I've not seen the question form, but there's some method of follow-up other than putting further questions in the feedback. This is not a problem with me, but there may be issues with me seeing additional questions if you put them there.
If you get a constant on/off pulse, that's an indicator that there are no codes stored. If the check engine lamp is on, that shouldn't be what you get. It's possible you were checking the transmission data stream instead of the engine datas stream. I doubt you've got a check engine lamp and no codes. If you can't read them, you should probably have them read for you at a shop that's capable of doing so.
Based on the jerk when you come to a stop, your idle switch (and other throttle body sensors) may not be properly set. The first place to start would be to clean the throttle body, make sure there's slack in the throttle cable, and adjust the idle switch, motor position sensor (idle actuator), and throttle position sensor.
This vehicle also has a known issue with a poor ground splice in the computer harness, causing a trouble code 15 (possibly with other codes). It's TSB 93-36-007. You can view it at www.hmaservice.com as well.
