Quite possible. The low vacuum could've caused the transmission modulator to up line pressure, putting a load on the engine at idle. Basically, the transmission thought you had the gas pedal pressed (which causes a drop in vacuum), so it compensated by trying to apply that power to the rear wheels. But at idle you're not moving, and the rpm's are so low that you just bog the engine down and kill it.
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Engine Idling Dilemma
- Thread starter jonward786
- Start date
Update:
Jon came by and talked to me at work yesterday. Said the car was still idling poor/shaky, but ran fine at higher rpm's. Holley tech and I both said vacuum leak. He then asked me about vacuum hose for the a/t vacuum modulator line. Turns out, the rubber hose hooked up to the modulator is super soft and loose on the nipple, which is likely causing a vacuum leak. After questioning, he also said he noticed an oil pool on the inside of the intake under the fitting where the modulator line connects.
I sent him off to one of our other local stores to pick up a new modulator, so hopefully he gets home ok
Edit: Apparently that didn't fix the issue. He's going to take it to a local shop to get it checked out=/
Jon came by and talked to me at work yesterday. Said the car was still idling poor/shaky, but ran fine at higher rpm's. Holley tech and I both said vacuum leak. He then asked me about vacuum hose for the a/t vacuum modulator line. Turns out, the rubber hose hooked up to the modulator is super soft and loose on the nipple, which is likely causing a vacuum leak. After questioning, he also said he noticed an oil pool on the inside of the intake under the fitting where the modulator line connects.
I sent him off to one of our other local stores to pick up a new modulator, so hopefully he gets home ok
Edit: Apparently that didn't fix the issue. He's going to take it to a local shop to get it checked out=/
jonward786
Member
And the saga continues. Since i head to my parents house for christmas, i just decided to trailer it home with a friends Yukon. Started it up, sounded good, nice and smooth. Let it warm up a bit then shifted into reverse and nothing happened. Back up into park, and down into reverse again, still nothing. Sigh, this had happened before when the pin that holds the shifted lever had fallen out, so i got under the car to see if that was the case again. Nope, it was still there.
So i lowered the car down, started it up and put it in reverse again. This time is shifted properly. Cool. So i decided to take a spin around the parking lot before loading it on the trailer just so see if it was still running well above idle speeds. But now there are bigger issues. Car is shifting into second and back into first and second and first and pretty much shifting however it sees fit. I would give it throttle and it would rev up and then seemingly slam into first after a couple seconds.
So the question is: did my torque converter just bite the dust? or maybe the new modulator isnt playing well with the tranny?
So i lowered the car down, started it up and put it in reverse again. This time is shifted properly. Cool. So i decided to take a spin around the parking lot before loading it on the trailer just so see if it was still running well above idle speeds. But now there are bigger issues. Car is shifting into second and back into first and second and first and pretty much shifting however it sees fit. I would give it throttle and it would rev up and then seemingly slam into first after a couple seconds.
So the question is: did my torque converter just bite the dust? or maybe the new modulator isnt playing well with the tranny?
daveSanborn
Active Member
When you removed the modulator.... did you notice a removable "pin" within the hole? This pin has to be inserted/aligned when installing the modulator.
jonward786
Member
Yeah, when the old modulator was pulled out, the pin came out with it. So i just kinda stuck the pin into the new one and screwed it in. maybe the pin is not in there correctly?