Odd occurance with throttle
10-29-2006, 07:41 PM
#1
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Join Date: Aug 2006
Location: Longview, TX
Posts: 199
Odd occurance with throttle
1994 Lt-1 fairly heavily modified shortblock and out.
Problem started about a month ago, used to be 50/50, now its 75/25 percent of the time from startup to shutdown the throttle requires significantly more effort to press as RPM's increase.
e.g. It took 10 N of force previously across the entire throttle position range previously, now it takes 10N of force at 0-20% throttle, 20N of force from 20-40% of throttle, 30N of force from 40-60% of throttle, et cetera. Obviously those are not the exact forces required, but you get the idea.
Thus far to figure out this problem I have completely stripepd down the throttle body and cleaned it, checked the spring linkage and throttle cable from start to finish, no new wear, no bindign, when the engine is not running throttle operates as it always had in the past. However once the engine is on, be it out of gear or in gear it requires siginificantly more force to move it as RPM's increase in an exponential fashion. So much so, that I'm literally worried about breaking the throttle cable while driving.
Other things I've tried is loading up the car and driving it with Datamaster's EE scanner running, reports show it as running exactly the same on all the sensors as before with no error codes....
I'm stumped!
Now if I hadn't been used to it requiring a linear 10N of force across the RPM range to depress the throttle then I would almost expect it slightly, my old car with a carb would behave radically different (throttle pressure required to accelerate) if it was lean or rich as opposed to dead on, more air forced through venturi's and throttle plates makes it increasingly difficult to operate them. But this is not the case.
Problem started about a month ago, used to be 50/50, now its 75/25 percent of the time from startup to shutdown the throttle requires significantly more effort to press as RPM's increase.
e.g. It took 10 N of force previously across the entire throttle position range previously, now it takes 10N of force at 0-20% throttle, 20N of force from 20-40% of throttle, 30N of force from 40-60% of throttle, et cetera. Obviously those are not the exact forces required, but you get the idea.
Thus far to figure out this problem I have completely stripepd down the throttle body and cleaned it, checked the spring linkage and throttle cable from start to finish, no new wear, no bindign, when the engine is not running throttle operates as it always had in the past. However once the engine is on, be it out of gear or in gear it requires siginificantly more force to move it as RPM's increase in an exponential fashion. So much so, that I'm literally worried about breaking the throttle cable while driving.
Other things I've tried is loading up the car and driving it with Datamaster's EE scanner running, reports show it as running exactly the same on all the sensors as before with no error codes....
I'm stumped!
Now if I hadn't been used to it requiring a linear 10N of force across the RPM range to depress the throttle then I would almost expect it slightly, my old car with a carb would behave radically different (throttle pressure required to accelerate) if it was lean or rich as opposed to dead on, more air forced through venturi's and throttle plates makes it increasingly difficult to operate them. But this is not the case.
10-30-2006, 03:06 PM
#5
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Join Date: Aug 2006
Location: Longview, TX
Posts: 199
completely loose, like a cable should..
side note, I've driven it twice today, no sign of the problem (only change being that I got around to ensuring the tranny fluid was at the right level (it was 1 cup-1 pint low (and as we all know even 1/10 of a cup low or high from the correct level of fluid will make the transmission behave radically different))
I don't see how this could effect anything as there is no kick-down linkage from the throttle to the tranny.
side note, I've driven it twice today, no sign of the problem (only change being that I got around to ensuring the tranny fluid was at the right level (it was 1 cup-1 pint low (and as we all know even 1/10 of a cup low or high from the correct level of fluid will make the transmission behave radically different))
I don't see how this could effect anything as there is no kick-down linkage from the throttle to the tranny.
10-31-2006, 09:00 AM
#7
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Join Date: Aug 2006
Location: Longview, TX
Posts: 199
definitely wasn't a floormat, I've been on the road nearly a dozen different times since I put the tranny fluid level back where it belongs and the problem has not yet repeated itself, which is very odd as there is no kickdown linkage...
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