1993 K Blazer, hard 1-2 shifts, non-PWM L460E
#1
06-30-2018, 11:10 PM
1993 K Blazer, hard 1-2 shifts, non-PWM L460E
Like night & day. Go to work, fine, coming home, hard shift between 1st & second.
Does this every day now, every 1-2 shift. All other shifts fine, overdrive seems okay,
(hard to tell, always thought it was too steep) and all gears work when manually selected.
TPS maybe? 1-2 shift solenoid? I'm leaning towards electrical, 'cause it happened
all at once, and not slowly over time like a tcc regulator wearing out.
My '93 is all stock, except for replaced exhaust piping. 195k miles.
Does this every day now, every 1-2 shift. All other shifts fine, overdrive seems okay,
(hard to tell, always thought it was too steep) and all gears work when manually selected.
TPS maybe? 1-2 shift solenoid? I'm leaning towards electrical, 'cause it happened
all at once, and not slowly over time like a tcc regulator wearing out.
My '93 is all stock, except for replaced exhaust piping. 195k miles.
#2
07-01-2018, 02:44 PM
Does this happen after an extended drive at highway speeds? Sounds a lot like high line pressure is being commanded after sensing a slip in the TCC circuit. Is the CEL light on?
#3
07-01-2018, 09:01 PM
Yes. This isn't neck-snapping, but it isn't subtle either. It punches harder 1-2 than it ever did before, warm/cold, easy or lead footed.
#5
07-02-2018, 02:51 AM
[QUOTE=Is the CEL light on?[/QUOTE]
I have a single OBD1 code, 32. It's for the EGR, which I disconnected.
I took it out today for many errands, mild or no hard shifting cold, harder shifts as the day went on. Mixed freeway and city driving.
I have a single OBD1 code, 32. It's for the EGR, which I disconnected.
I took it out today for many errands, mild or no hard shifting cold, harder shifts as the day went on. Mixed freeway and city driving.
#7
07-03-2018, 12:38 PM
4L60E. My '93 Blazer is almost stock, Never off road, and little or no towing. Stock wheels/tires. I'm leaving now to see a buddy, 6 miles away, freeway, uphill. I'll note the performance again.
#8
07-03-2018, 12:54 PM
Would you have a tach in the instrument cluster? That being a really early 4L60E it will be hard to pin point over a keyboard. What’s fluid condition? Have you recently done a fluid change? My feeling is the PCM is sensing a transmission component slipping and setting up line pressure to try and preserve itself. Can you feel lockup apply at highway speeds? If so as you feel it engage, stay at a steady speed and just touch your brake pedal and see if engine rpms will raise and let off the pedal to see if rpms go back down.
#9
07-03-2018, 04:08 PM
Yes, I have a tachometer. I just took a short little trip, and found that the hard 1-2 shift is intermittent after all. Does it cold and hot, but stronger when hot, & with most, but not every upshift. (accumulator piston?)
I do notice the lockup depending on how light my foot is on the accelerator, about 200rpm difference.. Next time out I will try deliberately dragging the brakes & watching RPM.
I do notice the lockup depending on how light my foot is on the accelerator, about 200rpm difference.. Next time out I will try deliberately dragging the brakes & watching RPM.
#10
07-04-2018, 05:49 AM
Very well could be the 1-2 accumulator. That year will have the aluminum piston but springs were known to break.