Weird Issue at roll to WOT... I think
07-27-2010, 07:13 PM
#1
Weird Issue at roll to WOT... I think Ok, weird issue, i may try to get a video this weekend.
But, if im at a dig, and mash to wot, i have no issue,
If im rolling at about 25mph and roll into the throttle to wot, i have no issue,
BUT...
If im rolling at just about any speed 25-45mph and just pull it into gear and mash it, or just mash it and let it kick down on its own, It goes weird, pedal on floor, afr goes -- on the gauge, car does not accelerate, and does not gain rpm, it sounds like its winding out, but its not doing anything.
little run down, built 4l60e with vaccum mod, yank 3200 single disc. and rearmounted turbo.
This issue did not start until recently, and im lost, when we logged it, it was weird, my tuner couldnt even explain what was happening.
I posted here as i wasnt sure if it was a trans/stall problem, or what.
Like i said, its fine under any condition except an immediate wot when rolling at lower speeds.
i thought i shimmed the converter according to specs given to me by yank, but would a converter thats not shimmed properly do this??
im lost.
But, if im at a dig, and mash to wot, i have no issue,
If im rolling at about 25mph and roll into the throttle to wot, i have no issue,
BUT...
If im rolling at just about any speed 25-45mph and just pull it into gear and mash it, or just mash it and let it kick down on its own, It goes weird, pedal on floor, afr goes -- on the gauge, car does not accelerate, and does not gain rpm, it sounds like its winding out, but its not doing anything.
little run down, built 4l60e with vaccum mod, yank 3200 single disc. and rearmounted turbo.
This issue did not start until recently, and im lost, when we logged it, it was weird, my tuner couldnt even explain what was happening.
I posted here as i wasnt sure if it was a trans/stall problem, or what.
Like i said, its fine under any condition except an immediate wot when rolling at lower speeds.
i thought i shimmed the converter according to specs given to me by yank, but would a converter thats not shimmed properly do this??
im lost.
07-27-2010, 07:32 PM
#2
Whats the trans line pressure when it does this?
Where do you have the vacuum hose for the trans connected?
With a turbo you need to run a check valve in the vacuum modulator hose, do you have that? Or is it run in a way where it'll pull vacuum at wot?
Where do you have the vacuum hose for the trans connected?
With a turbo you need to run a check valve in the vacuum modulator hose, do you have that? Or is it run in a way where it'll pull vacuum at wot?
07-27-2010, 10:34 PM
#4
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you cant have vacumm at WOT if you do this means that your intake is restricted lol. with a turbo under boost you wil have positive pressure in the intake which could be messing with the pressure signal to the modualtor.
07-27-2010, 10:45 PM
#5
Just like ported vacuum on a carb, venturi effect.
I was just asking questions to see how the guy is set up with it, I never said anything about a turbo manifold pulling vacuum.
07-28-2010, 10:56 AM
#7
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yes i understand that however transmissions do not use ported vacumm they use manifold vacumm to shift and for pressure control high vacumm=low TV, low Vacumm =high tv, ported vacumm will never send a correct signal and it will not reach 21hg, furthermore things would be opposite with ported vacumm at wot throttle you would have a high vacumm with ported which would be opposite as to what the modualtor would want to see at wot. and vise versa at CT or PT
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07-28-2010, 05:30 PM
#8
yes i understand that however transmissions do not use ported vacumm they use manifold vacumm to shift and for pressure control high vacumm=low TV, low Vacumm =high tv, ported vacumm will never send a correct signal and it will not reach 21hg, furthermore things would be opposite with ported vacumm at wot throttle you would have a high vacumm with ported which would be opposite as to what the modualtor would want to see at wot. and vise versa at CT or PT
Again, I'm asking the OP questions. I've seen people connect it to a vacuum source, the right one or the wrong one.
I never said **** about ever connecting it to ported vacuum, or to the manifold of a turbo car without the check valve.
07-28-2010, 07:45 PM
#10
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what's confusing me is your saying when you mash the pedal the rpm doesn't go up? If that is really what's going on, the issue that I think is creating the problem is your afr. If your afr goes lean off the gauge your not going to make power just noise.
If your not making power your rpm is not going to change just make alot of noise because the converter is loaded and trying to accelerate the vehicle.
If your not making power your rpm is not going to change just make alot of noise because the converter is loaded and trying to accelerate the vehicle.
07-28-2010, 10:32 PM
#11
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Are you ******* serious? you're giving me a lesson on how vacuum modulators work? You can't even spell vacuum OR modulator.
Again, I'm asking the OP questions. I've seen people connect it to a vacuum source, the right one or the wrong one.
I never said **** about ever connecting it to ported vacuum, or to the manifold of a turbo car without the check valve.
Again, I'm asking the OP questions. I've seen people connect it to a vacuum source, the right one or the wrong one.
I never said **** about ever connecting it to ported vacuum, or to the manifold of a turbo car without the check valve.
