Maybe Vacumn Problems?

MJWIDD

MEMBER
GMC

When I'm driving and let my foot of the gas, Then press the gas again it feels like it's shifting into overdrive and then it will downshift and accelerate. Sound like a vacumn leak.

Thursday, January 19th, 2006 AT 8:22 PM

6 Replies

SC1 RACING

MECHANIC
117 POSTS

Probably just the lock up converter.

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Friday, January 20th, 2006 AT 1:04 PM

MJWIDD

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12 POSTS

Where is that?

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Friday, January 20th, 2006 AT 4:14 PM

SC1 RACING

MECHANIC
117 POSTS

When you let off the gas and coast the converter will unlock then when you get back on the gas the vehical is still in over drive. What you feel is the lock up converter kicking in.

If you have an overdrive transmission start out and count the times it changes. It will go to 1st, 2nd. Drive, then overdrive. Then the converter will lock up and it will feel like another gear. When you let off the gas the converter unlocks and it stays in o/d unless you give it alot of gas to kick down to drive.

Unless it picks up rpm to 2,500-3,000 when it does this everything is fine.

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Friday, January 20th, 2006 AT 4:20 PM

MJWIDD

MEMBER
12 POSTS

Thats exactly what it does, how do I fix it?

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Friday, January 20th, 2006 AT 4:22 PM

SC1 RACING

MECHANIC
117 POSTS

If the rpm jumps that high more than likely it is something in the engine. Really hard to tell. You have so many options that work with when the trans shifts. Do you hear any pinging noise when you are exelrating or climbing a hill? Would be best to scan the computer for codes. To make sure all sensors are in good shape.

Did you mean it jumps up to 2500 while gently getting back in the gas?