Rebuilt 4L60E issues. Finally fixed!
Moderator
Joined: Aug 2010
Posts: 7,323
Likes: 529
From: Ann Arbor, MI
@mrvedit i got a transgo .500 boost valve from a local builder. Got it out in a pressure is up, but not up to where I’ve seen people state. Reverse is low until I press on the gas and it shoots up past 90PSI for sure. The delayed engagement that I was feeling on take off is shorter. But I still have the fluctuation in RPM in 4th gear. Could this be the PR valve above the boost valve?
Hopefully one of the more experienced trans builders will chime in here to answer your question as it is outside of my limited experience.
If your trans pressure gauge is still hooked up and your trans connector is easily reachable, it might be useful to know what your pressures are in Park, Reverse and Drive with the connector off.
Thread Starter
Staging Lane
Joined: May 2022
Posts: 98
Likes: 4
@mrvedit UPDATE:
line pressure with main unplugged is as follows.
Park from start goes up to 180 then settles at 118-120.
Reverse is 110-113.
Drive is 100.
I find this interesting because I had read before that if main was unplugged and pressure was high, then it was an electronic issue. I tried this before the boost valve and the line pressure was lower than that with it plugged in.
line pressure with main unplugged is as follows.
Park from start goes up to 180 then settles at 118-120.
Reverse is 110-113.
Drive is 100.
I find this interesting because I had read before that if main was unplugged and pressure was high, then it was an electronic issue. I tried this before the boost valve and the line pressure was lower than that with it plugged in.
TECH Junkie
Joined: May 2012
Posts: 3,050
Likes: 716
From: Poplarville, MS
I missed where you posted what line pressure is at 2000 rpm. When did this problem start, was is after the last converter change or immediately after rebuild? I am thinking that something is wrong in the pump, (like a stuck pump slide) and that an autopsy is going to be needed to find the problem.
When unplugging the harness on the side of the trans you remove all electronic control of line pressure. With pug undone you will see the max pressure that the pump is able to produce with all systems install correctly. These pressures should be 170psi or higher at 1500 to 2000 rpm. For some reason, with is not electronic your pressures are way too low. Imo it is time to take it back apart.
When unplugging the harness on the side of the trans you remove all electronic control of line pressure. With pug undone you will see the max pressure that the pump is able to produce with all systems install correctly. These pressures should be 170psi or higher at 1500 to 2000 rpm. For some reason, with is not electronic your pressures are way too low. Imo it is time to take it back apart.
Thread Starter
Staging Lane
Joined: May 2022
Posts: 98
Likes: 4
I missed where you posted what line pressure is at 2000 rpm. When did this problem start, was is after the last converter change or immediately after rebuild? I am thinking that something is wrong in the pump, (like a stuck pump slide) and that an autopsy is going to be needed to find the problem.
When unplugging the harness on the side of the trans you remove all electronic control of line pressure. With pug undone you will see the max pressure that the pump is able to produce with all systems install correctly. These pressures should be 170psi or higher at 1500 to 2000 rpm. For some reason, with is not electronic your pressures are way too low. Imo it is time to take it back apart.
When unplugging the harness on the side of the trans you remove all electronic control of line pressure. With pug undone you will see the max pressure that the pump is able to produce with all systems install correctly. These pressures should be 170psi or higher at 1500 to 2000 rpm. For some reason, with is not electronic your pressures are way too low. Imo it is time to take it back apart.
TECH Junkie
Joined: May 2012
Posts: 3,050
Likes: 716
From: Poplarville, MS
@bbond105
i would also like to add what I found at 1500 to 2000 rpm with main unplugged
park: 240 max out
reverse: 250
drive: 240
i would also like to add what I found at 1500 to 2000 rpm with main unplugged
park: 240 max out
reverse: 250
drive: 240
Put the trans in drive and do a power brake up to 2000rpm for a few seconds, just long enough to see what the highest line pressure reading is. If the pressures are low and we now that know that the pump is capable of making the proper pressures we need to determined why it is low when the trans is plugged up. I saw where you said you replaced all solenoids but I want to verify if the EPC solenoid was replaced.
Do you have a scanner or HP Tuners that will allow you to control the EPC solenoid? If so decrease the amps to the EPC solenoid while monitoring the line pressure. Do this above idle rpm. The less amps to the EPC the higher the line pressure, the more amps to the EPC the lower the line pressure.
Last edited by bbond105; May 28, 2022 at 08:14 PM.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo Thread Starter
Staging Lane
Joined: May 2022
Posts: 98
Likes: 4
That helps a lot!! The pump is making good pressure.
Put the trans in drive and do a power brake up to 2000rpm for a few seconds, just long enough to see what the highest line pressure reading is. If the pressures are low and we now that know that the pump is capable of making the proper pressures we need to determined why it is low when the trans is plugged up. I saw where you said you replaced all solenoids but I want to verify if the EPC solenoid was replaced.
Do you have a scanner or HP Tuners that will allow you to control the EPC solenoid? If so decrease the amps to the EPC solenoid while monitoring the line pressure. Do this above idle rpm. The less amps to the EPC the higher the line pressure, the more amps to the EPC the lower the line pressure.
Put the trans in drive and do a power brake up to 2000rpm for a few seconds, just long enough to see what the highest line pressure reading is. If the pressures are low and we now that know that the pump is capable of making the proper pressures we need to determined why it is low when the trans is plugged up. I saw where you said you replaced all solenoids but I want to verify if the EPC solenoid was replaced.
Do you have a scanner or HP Tuners that will allow you to control the EPC solenoid? If so decrease the amps to the EPC solenoid while monitoring the line pressure. Do this above idle rpm. The less amps to the EPC the higher the line pressure, the more amps to the EPC the lower the line pressure.
TECH Junkie
Joined: May 2012
Posts: 3,050
Likes: 716
From: Poplarville, MS
That helps a lot!! The pump is making good pressure.
Put the trans in drive and do a power brake up to 2000rpm for a few seconds, just long enough to see what the highest line pressure reading is. If the pressures are low and we now that know that the pump is capable of making the proper pressures we need to determined why it is low when the trans is plugged up. I saw where you said you replaced all solenoids but I want to verify if the EPC solenoid was replaced.
Do you have a scanner or HP Tuners that will allow you to control the EPC solenoid? If so decrease the amps to the EPC solenoid while monitoring the line pressure. Do this above idle rpm. The less amps to the EPC the higher the line pressure, the more amps to the EPC the lower the line pressure.
Put the trans in drive and do a power brake up to 2000rpm for a few seconds, just long enough to see what the highest line pressure reading is. If the pressures are low and we now that know that the pump is capable of making the proper pressures we need to determined why it is low when the trans is plugged up. I saw where you said you replaced all solenoids but I want to verify if the EPC solenoid was replaced.
Do you have a scanner or HP Tuners that will allow you to control the EPC solenoid? If so decrease the amps to the EPC solenoid while monitoring the line pressure. Do this above idle rpm. The less amps to the EPC the higher the line pressure, the more amps to the EPC the lower the line pressure.
TECH Junkie
Joined: May 2012
Posts: 3,050
Likes: 716
From: Poplarville, MS
@bbond105
Do you mean foot on break and pressing gas? I can do that no problem.
as far as controlling the EPC, I’m not sure how else to do it without a scanner.
Do you mean foot on break and pressing gas? I can do that no problem.
as far as controlling the EPC, I’m not sure how else to do it without a scanner.
Thread Starter
Staging Lane
Joined: May 2022
Posts: 98
Likes: 4
@bbond105
I don't have a scanner, just a reader that is Bluetooth to my iPad. Basic diagnostics only. I have asked around to a few people that may have one, but no one has one that reads transmission data.
I will record the pressures when I get home from work this evening around 7:30 pm eastern time.
I don't have a scanner, just a reader that is Bluetooth to my iPad. Basic diagnostics only. I have asked around to a few people that may have one, but no one has one that reads transmission data.
I will record the pressures when I get home from work this evening around 7:30 pm eastern time.
Thread Starter
Staging Lane
Joined: May 2022
Posts: 98
Likes: 4
im still trying to find someone that can scan for me.
I appreciate your help man.
Thread Starter
Staging Lane
Joined: May 2022
Posts: 98
Likes: 4
Can anyone here help me understand two things.
1. How does the torque converter apply when I press on the gas?
2. Does TCC valve have anything to do with that?
im wondering if what I’m feeling at take off is a leak in that regard. If another valve is worn out or wrong.
thanks to everyone for their help that has gotten me this far, and thanks in advance to anyone else who chimes in.
1. How does the torque converter apply when I press on the gas?
2. Does TCC valve have anything to do with that?
im wondering if what I’m feeling at take off is a leak in that regard. If another valve is worn out or wrong.
thanks to everyone for their help that has gotten me this far, and thanks in advance to anyone else who chimes in.
TECH Junkie
Joined: May 2012
Posts: 3,050
Likes: 716
From: Poplarville, MS
Can anyone here help me understand two things.
1. How does the torque converter apply when I press on the gas?
The Torque Converter Clutch should only apply in 3rd and 4th gears at speeds above 35mph. A quick way to test engagement is to lightly apply brake pedal just enough to turn on the brake lights but not engaging the brakes. This should cause the TCC to not apply while applying the brake pedal or if applied unlock the clutch.
2. Does TCC valve have anything to do with that?
The TCC valve has a lot to do with TCC apply. Usually a worn TCC valve will not let the TCC apply.
im wondering if what I’m feeling at take off is a leak in that regard. If another valve is worn out or wrong.
More info on what you are feeling would be useful. Like what gear do you feel your issue in, speed, and throttle position.
thanks to everyone for their help that has gotten me this far, and thanks in advance to anyone else who chimes in.
1. How does the torque converter apply when I press on the gas?
The Torque Converter Clutch should only apply in 3rd and 4th gears at speeds above 35mph. A quick way to test engagement is to lightly apply brake pedal just enough to turn on the brake lights but not engaging the brakes. This should cause the TCC to not apply while applying the brake pedal or if applied unlock the clutch.
2. Does TCC valve have anything to do with that?
The TCC valve has a lot to do with TCC apply. Usually a worn TCC valve will not let the TCC apply.
im wondering if what I’m feeling at take off is a leak in that regard. If another valve is worn out or wrong.
More info on what you are feeling would be useful. Like what gear do you feel your issue in, speed, and throttle position.
thanks to everyone for their help that has gotten me this far, and thanks in advance to anyone else who chimes in.
Thread Starter
Staging Lane
Joined: May 2022
Posts: 98
Likes: 4
so the two main issues now are the fluctuations in RPM when at speeds of 45-60 MPH. Seems as if torque converter is slipping or something. I’m not sure if that is the case.
the other issue is when applying gas from start, the pressure and RPM raises, but the transmission hardly reacts until it reaches over 90PSI, at which I feel it somewhat jump into gear. As if a band or something is not being applied correctly.