New EPCS (force motor) solenoid. Shift points different, bounces off rev limiter WOT
06-09-2015, 05:30 AM
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New EPCS (force motor) solenoid. Shift points different, bounces off rev limiter WOT So I replaced the Electronic Pressure Control Solenoid in my 97 Trans Am. All of the shift points seem higher and WOT it bounces off the rev limiter. Did I need to reset my PCM? Did I screw myself messing with the transmission (178k miles)? The shifts are fine, but everything else is out of whack. I refilled what came out when I dropped the trans pan.
06-09-2015, 08:56 AM
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I reset the PCM and put in a new TPS--no fix. I had to pull the 1-2 accumulator housing to get the EPCS out. I'm thinking I messed up something reinstalling it. Replace the springs?
Edit: Ordered a new 1-2 accumulator piston and springs. I'm hoping this was the problem and I disturbed something that can be fixed.
Edit: Ordered a new 1-2 accumulator piston and springs. I'm hoping this was the problem and I disturbed something that can be fixed.
Last edited by reservoirdogs12; 06-09-2015 at 09:40 AM.
06-10-2015, 09:07 AM
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Exactly. Hook up a pressure gauge to monitor the pressure during shifts. You can buy one on Amazon for $34 (ATD-5550). I suspect you PCS just isn't calibrated correctly. They can be adjusted.
While new springs and piston for you 1-2 accumulator are a good idea, I don't think that is your problem.
While new springs and piston for you 1-2 accumulator are a good idea, I don't think that is your problem.
06-12-2015, 12:02 PM
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Exactly. Hook up a pressure gauge to monitor the pressure during shifts. You can buy one on Amazon for $34 (ATD-5550). I suspect you PCS just isn't calibrated correctly. They can be adjusted.
While new springs and piston for you 1-2 accumulator are a good idea, I don't think that is your problem.
While new springs and piston for you 1-2 accumulator are a good idea, I don't think that is your problem.
06-18-2015, 03:35 PM
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So I lost 3rd and 4th gear. I pulled the pan and found that a wire had melted. I attempted to cut down and resolder/heat shrink it, but the problem is still here. It actually reaches a certain speed in second and just disengages as though I'm in neutral.
Worn 3-4 clutch pack? Bad harness or shift solenoids?
Worn 3-4 clutch pack? Bad harness or shift solenoids?
06-23-2015, 10:29 PM
#7
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Sorry for the slow reply - I was on vacation.
A wire should not melt; never heard of that.
While a worn out 3/4 clutch is a high probability, I often first suggest lower probability solutions because they don't require removing the trans and aren't too expensive.
Considering your melted wire, I therefore suggest a new harness and new solenoids, which is exactly what you are thinking too. They should be replaced during a rebuild anyway. You might need to pull and rebuild the trans, but lets start by replacing the electrical parts.
A wire should not melt; never heard of that.
While a worn out 3/4 clutch is a high probability, I often first suggest lower probability solutions because they don't require removing the trans and aren't too expensive.
Considering your melted wire, I therefore suggest a new harness and new solenoids, which is exactly what you are thinking too. They should be replaced during a rebuild anyway. You might need to pull and rebuild the trans, but lets start by replacing the electrical parts.
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06-26-2015, 02:37 AM
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Sorry for the slow reply - I was on vacation.
A wire should not melt; never heard of that.
While a worn out 3/4 clutch is a high probability, I often first suggest lower probability solutions because they don't require removing the trans and aren't too expensive.
Considering your melted wire, I therefore suggest a new harness and new solenoids, which is exactly what you are thinking too. They should be replaced during a rebuild anyway. You might need to pull and rebuild the trans, but lets start by replacing the electrical parts.
A wire should not melt; never heard of that.
While a worn out 3/4 clutch is a high probability, I often first suggest lower probability solutions because they don't require removing the trans and aren't too expensive.
Considering your melted wire, I therefore suggest a new harness and new solenoids, which is exactly what you are thinking too. They should be replaced during a rebuild anyway. You might need to pull and rebuild the trans, but lets start by replacing the electrical parts.
I have no idea how it melted either. Maybe the insulation was rubbed off somehow. I'm just biting the bullet and saving for a rebuild at this point. With almost 180k miles I'm probably better off getting a rebuild over with while I'm not really busy.