93 vette Missing
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Joined: Feb 2013
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From: CA
93 vette Missing
I have a 1993 Corvette. I've changed the spark plugs/wires,EGR Valve and the ECT, but it's still missing. It vibrate when down shifting between 42 and 45 MPH and when accelerating between 62 and 69, exspecially when I try and used the cruize control. Does anyone have answer to this ongoing problem?
P S:I just had the trans rebuilt as it was sitting for approx 2years. However, I changed the fuel filter about a year prior the to the trans going bad.
Thanks...
P S:I just had the trans rebuilt as it was sitting for approx 2years. However, I changed the fuel filter about a year prior the to the trans going bad.
Thanks...
Last edited by NJD; Mar 10, 2013 at 01:47 AM. Reason: missing words
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Joined: Sep 2010
Posts: 3,752
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From: Indiana PA
Does it ever miss at idle?
Any codes?
Hot? Cold? Warm?
Could be a lot of things....Opti-Spark, ICM, ECM, Wiring, Coil,etc...and we are just talking ignition system.
Not sure how the tranny is part of this unless you suspect the "vibration" is from it.
I've never described a mis fire as a vibration. Usually they are intermittent and the car kinda studders. IDK?
What I'm trying to say is, its hard to diagnose over the internet. I need more details. As many as possible.
Any codes?
Hot? Cold? Warm?
Could be a lot of things....Opti-Spark, ICM, ECM, Wiring, Coil,etc...and we are just talking ignition system.
Not sure how the tranny is part of this unless you suspect the "vibration" is from it.
I've never described a mis fire as a vibration. Usually they are intermittent and the car kinda studders. IDK?
What I'm trying to say is, its hard to diagnose over the internet. I need more details. As many as possible.
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From: CA
Ok 93 Rubie,
It starts at start up Cold to warm w/no codes. The only codes registered were for the EGR Valve and the ECT sensor, which I've replaced both. At stop light/sign while stepping on the brake, it appears to sort of a slight jerk, just slightly, not sever. 2ndly:While driving it begins to vibrate when down shifting, or accelerating between 42-46 mpr. However, if I step on the gas to acceleration to approx 48-50 the vibration stops, but starts again when I'm using the cruse control and accel between 62-66 mpr.
I had the Opti-Spark about 3-4years ago. Aprox 1-2 years later the transmission went out. So the car set parked for approx 2 and half years. I finally had the tranny re-built.
Thanks,
It starts at start up Cold to warm w/no codes. The only codes registered were for the EGR Valve and the ECT sensor, which I've replaced both. At stop light/sign while stepping on the brake, it appears to sort of a slight jerk, just slightly, not sever. 2ndly:While driving it begins to vibrate when down shifting, or accelerating between 42-46 mpr. However, if I step on the gas to acceleration to approx 48-50 the vibration stops, but starts again when I'm using the cruse control and accel between 62-66 mpr.
I had the Opti-Spark about 3-4years ago. Aprox 1-2 years later the transmission went out. So the car set parked for approx 2 and half years. I finally had the tranny re-built.
Thanks,
Last edited by NJD; Mar 11, 2013 at 02:06 AM.
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Joined: Sep 2010
Posts: 3,752
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From: Indiana PA
Ok 93 Rubie,
It starts at start up Cold to warm w/no codes. The only codes registered were for the EGR Valve and the ECT sensor, which I've replaced both. At stop light/sign while stepping on the brake, it appears to sort of a slight jerk, just slightly, not sever. 2ndly:While driving it begins to vibrate when down shifting, or accelerating between 42-46 mpr. However, if I step on the gas to acceleration to approx 48-50 the vibration stops, but starts again when I'm using the cruse control and accel between 62-66 mpr.
I had the Opti-Spark about 3-4years ago. Aprox 1-2 years later the transmission went out. So the car set parked for approx 2 and half years. I finally had the tranny re-built.
Thanks,
It starts at start up Cold to warm w/no codes. The only codes registered were for the EGR Valve and the ECT sensor, which I've replaced both. At stop light/sign while stepping on the brake, it appears to sort of a slight jerk, just slightly, not sever. 2ndly:While driving it begins to vibrate when down shifting, or accelerating between 42-46 mpr. However, if I step on the gas to acceleration to approx 48-50 the vibration stops, but starts again when I'm using the cruse control and accel between 62-66 mpr.
I had the Opti-Spark about 3-4years ago. Aprox 1-2 years later the transmission went out. So the car set parked for approx 2 and half years. I finally had the tranny re-built.
Thanks,
At the stop sign is it a constant jerk like its pulsing?
Did the tranny ever operate correctly in the car since it was reinstalled?
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From: CA
93 Miss
Yes, at the stop sign, it feels like its a knock rough idle sensations. As far as the tranny goes, I took the car back to the shop where I had it rebuilt and re-installed. However, due to the missing, they weren't able to determine if somethings actually wrong with the tranny.
However, I drove it to work today. It still has power, but I just keep expriencing the vibaration at each interm. On my way home from work, the service engine light did come on. I stopped by my machanic and he hook up the diag and the code 32 registered. He seems to thing that the EGR solenoid maybe bad and thinks that might be causing it to miss. I did notice that my MPG takes a little longer to increase when I'm on the highway. It increases about 1.5 mpr per every 10 miles. However, when I first replaced the EGR Valve it was increasing rapidly. Again, thats not case now.
what do you think....Thanks
However, I drove it to work today. It still has power, but I just keep expriencing the vibaration at each interm. On my way home from work, the service engine light did come on. I stopped by my machanic and he hook up the diag and the code 32 registered. He seems to thing that the EGR solenoid maybe bad and thinks that might be causing it to miss. I did notice that my MPG takes a little longer to increase when I'm on the highway. It increases about 1.5 mpr per every 10 miles. However, when I first replaced the EGR Valve it was increasing rapidly. Again, thats not case now.
what do you think....Thanks
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Joined: Sep 2010
Posts: 3,752
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From: Indiana PA
Definilty sounds like a misfire to be sure at this point.
The EGR if operating at idle will DEFINITELY cause misfire. I would pursue that option and then see how it does. Improper EGR operation will also affect gas mileage as you noted.
The EGR if operating at idle will DEFINITELY cause misfire. I would pursue that option and then see how it does. Improper EGR operation will also affect gas mileage as you noted.
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Joined: Feb 2013
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From: CA
DinBob,
You might be right about the torque converter contributing to the vibration, but I don't think it's contributing to the misfire. Unfortunately, the tranny mechanic who rebuilt the tranny is unable to determine that until I can get the misfire issue resloved. So he says.
Thanks
You might be right about the torque converter contributing to the vibration, but I don't think it's contributing to the misfire. Unfortunately, the tranny mechanic who rebuilt the tranny is unable to determine that until I can get the misfire issue resloved. So he says.
Thanks