'93 1.6L valve adjustment
pdonnell
01-16-2004, 07:31 PM
After looking at the engine mounts for a low level vibration. Higher level after car has been sitting a few days out in the cold. I am going to do my valve adjusment on this rolla. Since buying it new in '93 its never been done. So I figure I'll tune it up and adjust the valves. Ordered a valve adjustment tool today and will get a micrometer at home depot. I've done more complicated valve adjustments (removal of cam's) so its pretty straight forward.
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Since the motor mounts look good I figure a poorly tuned engine might be the cause of the vibration. Who knows. But it needs a tune up anyway as I got it smogged the other day and the hydrocarbons registered 92. (Calif limit is 93) And I wasn't getting any faults on the O2 sensor. So what the hey.
.
Anyways has anyone done there own adjustment? How did the car run after the valves were adjusted.?
.
Just curious.
.
Since the motor mounts look good I figure a poorly tuned engine might be the cause of the vibration. Who knows. But it needs a tune up anyway as I got it smogged the other day and the hydrocarbons registered 92. (Calif limit is 93) And I wasn't getting any faults on the O2 sensor. So what the hey.
.
Anyways has anyone done there own adjustment? How did the car run after the valves were adjusted.?
.
Just curious.
TekPhobia
01-18-2004, 05:51 AM
After looking at the engine mounts for a low level vibration. Higher level after car has been sitting a few days out in the cold. I am going to do my valve adjusment on this rolla. Since buying it new in '93 its never been done. So I figure I'll tune it up and adjust the valves. Ordered a valve adjustment tool today and will get a micrometer at home depot. I've done more complicated valve adjustments (removal of cam's) so its pretty straight forward.
.
Since the motor mounts look good I figure a poorly tuned engine might be the cause of the vibration. Who knows. But it needs a tune up anyway as I got it smogged the other day and the hydrocarbons registered 92. (Calif limit is 93) And I wasn't getting any faults on the O2 sensor. So what the hey.
.
Anyways has anyone done there own adjustment? How did the car run after the valves were adjusted.?
.
Just curious.
Whoa, you're running pretty rich! That can make it vibrate more than usual.
Anyways, for the valves. I doubt that they're that much out of spec to cause a vibration. All you need is some time and a feeler gauge to check the lash. The numbers will be on the VECI sticker. IIRC, Exhaust is 0.25-0.35mm (0.0010 -0.014 in.) and Intake is 0.20 - 0.30mm (0.008 - 0.012 in.). If the measurements are really outta wack, sometimes you can swap shims. Forget going to the dealer for shims...they're going to be around $10 each!
I haven't tried it yet, but I believe you can get them from a Yamaha dealer as some of their engines used shim overbucket designs. Plus, they've designed a lot of Toyota's engines (heads mainly).
How did you go about testing the O2 sensor to make sure it was working correctly?
-Tim
.
Since the motor mounts look good I figure a poorly tuned engine might be the cause of the vibration. Who knows. But it needs a tune up anyway as I got it smogged the other day and the hydrocarbons registered 92. (Calif limit is 93) And I wasn't getting any faults on the O2 sensor. So what the hey.
.
Anyways has anyone done there own adjustment? How did the car run after the valves were adjusted.?
.
Just curious.
Whoa, you're running pretty rich! That can make it vibrate more than usual.
Anyways, for the valves. I doubt that they're that much out of spec to cause a vibration. All you need is some time and a feeler gauge to check the lash. The numbers will be on the VECI sticker. IIRC, Exhaust is 0.25-0.35mm (0.0010 -0.014 in.) and Intake is 0.20 - 0.30mm (0.008 - 0.012 in.). If the measurements are really outta wack, sometimes you can swap shims. Forget going to the dealer for shims...they're going to be around $10 each!
I haven't tried it yet, but I believe you can get them from a Yamaha dealer as some of their engines used shim overbucket designs. Plus, they've designed a lot of Toyota's engines (heads mainly).
How did you go about testing the O2 sensor to make sure it was working correctly?
-Tim
pdonnell
01-18-2004, 03:24 PM
Actually intake in the book indicates .006-.010 inch.
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Thank's for the heads up about the shims. I know the state of tune of the motor (valves,plugs, filters etc...) is a long shot as to causing the vibration but the motor needs it anyway.
.
Regarding the O2 sensor. From what I've read the ECM contains a built in diagnostic system. (using flash pulses of the engine light after you've started the car. I've jump the terminals TE1 and E1. The check engine light flashed an output of code 1 (i.e. normal) which is a flash every .25/second. Code 26 is for oxygen sensor or circuit. Maybe what I'll do is erase any codes in memory and operate the car and look for any ECM codes that I may have missed in the past. Or (in worse case) take it to a dealer for a reading. You erase any stored codes by removing for 10 seconds the 15A EFI fuse located right behind the battery.
.
So bottom line is that the diagnosis of the O2 sensor is within the ECM. Although I'm still going to get a voltmeter and check the voltage output of the O2 sensor. It may be running in "open loop" mode. A default mode when the sensor is bad. If its working correctly the volts should measure 0.1-0.9 volts if its running correctly. Basically you use the voltmeter to probe the contact point where it plugs into the circuit a few inches behind the sensor. Pretty easy really. Gotta remember though this car has a dual O2 sensor. One at the exhaust manifold and another just in front of the catalytic converter.
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I would think the ECM (cars computer) would be able to tell me. But checking the voltage output of the O2 sensor once the car is at operating tempature should be easy enough.
.
Thank's for the heads up about the shims. I know the state of tune of the motor (valves,plugs, filters etc...) is a long shot as to causing the vibration but the motor needs it anyway.
.
Regarding the O2 sensor. From what I've read the ECM contains a built in diagnostic system. (using flash pulses of the engine light after you've started the car. I've jump the terminals TE1 and E1. The check engine light flashed an output of code 1 (i.e. normal) which is a flash every .25/second. Code 26 is for oxygen sensor or circuit. Maybe what I'll do is erase any codes in memory and operate the car and look for any ECM codes that I may have missed in the past. Or (in worse case) take it to a dealer for a reading. You erase any stored codes by removing for 10 seconds the 15A EFI fuse located right behind the battery.
.
So bottom line is that the diagnosis of the O2 sensor is within the ECM. Although I'm still going to get a voltmeter and check the voltage output of the O2 sensor. It may be running in "open loop" mode. A default mode when the sensor is bad. If its working correctly the volts should measure 0.1-0.9 volts if its running correctly. Basically you use the voltmeter to probe the contact point where it plugs into the circuit a few inches behind the sensor. Pretty easy really. Gotta remember though this car has a dual O2 sensor. One at the exhaust manifold and another just in front of the catalytic converter.
.
I would think the ECM (cars computer) would be able to tell me. But checking the voltage output of the O2 sensor once the car is at operating tempature should be easy enough.
TekPhobia
01-18-2004, 03:38 PM
Actually intake in the book indicates .006-.010 inch.
.
Thank's for the heads up about the shims. I know the state of tune of the motor (valves,plugs, filters etc...) is a long shot as to causing the vibration but the motor needs it anyway.
.
Regarding the O2 sensor. From what I've read the ECM contains a built in diagnostic system. (using flash pulses of the engine light after you've started the car. I've jump the terminals TE1 and E1. The check engine light flashed an output of code 1 (i.e. normal) which is a flash every .25/second. Code 26 is for oxygen sensor or circuit. Maybe what I'll do is erase any codes in memory and operate the car and look for any ECM codes that I may have missed in the pass. Or (in worse case) take it to a dealer for a reading.
Yea, my apologies. I went to double-check my information and looked at the wrong specs. Here's the correct data:
Intake: 0.15 - 0.25 mm (0.006 - 0.010 in.)
Exhaust: 0.20 - 0.30 mm (0.008 - 0.012 in.)
Yes, a nice tune-up could do wonders. Who knows, maybe the rough idle is a misfire, which would account for the high HC's.
The ECU will only set the CEL when the O2 is stuck in a certain state (either lean or rich). It won't trip the CEL if the O2 is sluggish. The best way to check the O2 sensor is with an oscilloscope or an analog voltmeter. You're wanting to see the voltage cycle between roughly .2V and .9V at a 2500 RPM. If it's sluggish or doesn't respond, then that's your culprit for high HC's.
-Tim
.
Thank's for the heads up about the shims. I know the state of tune of the motor (valves,plugs, filters etc...) is a long shot as to causing the vibration but the motor needs it anyway.
.
Regarding the O2 sensor. From what I've read the ECM contains a built in diagnostic system. (using flash pulses of the engine light after you've started the car. I've jump the terminals TE1 and E1. The check engine light flashed an output of code 1 (i.e. normal) which is a flash every .25/second. Code 26 is for oxygen sensor or circuit. Maybe what I'll do is erase any codes in memory and operate the car and look for any ECM codes that I may have missed in the pass. Or (in worse case) take it to a dealer for a reading.
Yea, my apologies. I went to double-check my information and looked at the wrong specs. Here's the correct data:
Intake: 0.15 - 0.25 mm (0.006 - 0.010 in.)
Exhaust: 0.20 - 0.30 mm (0.008 - 0.012 in.)
Yes, a nice tune-up could do wonders. Who knows, maybe the rough idle is a misfire, which would account for the high HC's.
The ECU will only set the CEL when the O2 is stuck in a certain state (either lean or rich). It won't trip the CEL if the O2 is sluggish. The best way to check the O2 sensor is with an oscilloscope or an analog voltmeter. You're wanting to see the voltage cycle between roughly .2V and .9V at a 2500 RPM. If it's sluggish or doesn't respond, then that's your culprit for high HC's.
-Tim
pdonnell
01-18-2004, 03:45 PM
Yea, I was thinking checking the actual volts was the better way to go. Thank's for the heads up about the ECM.
.
My brother tells me its common for O2 sensors to go after 100,000 miles. I checked with the stealer the other day and they want $120 for the front one. Those bastards!!!
.
Heres a good article on O2 sensor for the rest of us.
.
http://www.aera.org/Techside/oxygen_sensors_101.htm
.
My brother tells me its common for O2 sensors to go after 100,000 miles. I checked with the stealer the other day and they want $120 for the front one. Those bastards!!!
.
Heres a good article on O2 sensor for the rest of us.
.
http://www.aera.org/Techside/oxygen_sensors_101.htm
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