Not shifting when I mash down on the accelerator

Tiny
JASONPYZO
  • MEMBER
  • 1993 CHEVROLET 1500
  • 5.7L
  • V8
  • 2WD
  • AUTOMATIC
  • 180,000 MILES
Alright, with my truck when I'm driving normal and not getting on it the truck runs well. But when I mash down on the accelerator from a complete stop it shifts really quick from first to second then third. But as I said if I drive regularly it shifts fine. I thought it was a transmission issue all together but I was talking to so folks and said it might be throttle position sensor, a shift solenoid, speed sensor or even computer issues. So I was wondering if you had an input on this problem that might help me?
Thursday, December 10th, 2020 AT 12:33 PM

8 Replies

Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

There are a few different things that can cause this issue. Tell me, does it transmission shift at the same speed regardless of throttle pressure? Also, have you scanned for diagnostic trouble codes? This vehicle has an OBD1 system that doesn't require a scan tool to retrieve codes. All that is needed is a short jumper wire or even a paper clip.

If you haven't already checked, follow this link and see if any codes are present.

https://www.2carpros.com/articles/buick-cadillac-chevy-gmc-oldsmobile-pontiac-gm-1983-1995-obd1-code-definitions-and-retrieval-method

Try that and let me know what you find.

Joe
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Friday, May 14th, 2021 AT 11:23 AM
Tiny
JASONPYZO
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Well, when you press down on the accelerator in normal driving conditions it shifts just fine, let's say it's when I need to cut out into traffic quickly from a complete stop it does that quick shift from first to second and third and I mean in a matter of seconds. I try the other think you mentioned with trying to retrieve any codes and let you know what I find.
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Friday, May 14th, 2021 AT 11:23 AM
Tiny
JASONPYZO
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Okay, I just checked for codes on the truck and system came back normal. It kept flashing 12, I let it flash 15 times so no code present.
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Friday, May 14th, 2021 AT 11:23 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
Hi,

That is the opposite of what it should do. First, check the connection at the control module under the dash. See the attached pic. See if anything is loose, corroded, or damaged.

If it checks good, I have a feeling the control module needs to be reprogrammed.

Let me know.
Joe
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Friday, May 14th, 2021 AT 11:23 AM
Tiny
JASONPYZO
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  • 87 POSTS
Alright I'll check that. Thanks
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Friday, May 14th, 2021 AT 11:23 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
  • 110,176 POSTS
You are very welcome. If you have a chance, let me know what you find.

Joe
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Friday, May 14th, 2021 AT 11:23 AM
Tiny
JASONPYZO
  • MEMBER
  • 87 POSTS
Hey Joe, some crazy stuff happening. The truck seems to shift fine now, I don't know what is going on. I'm going to just put that off to the side for now. Now it's back Dodge Dakota again with that misfire. I'll write on that question thread that we were chat on so you can scroll back if need be to refresh your memory on what we were doing, thanks again.
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Friday, May 14th, 2021 AT 11:23 AM
Tiny
JACOBANDNICKOLAS
  • MECHANIC
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Sounds good.

Take care,
Joe
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Friday, May 14th, 2021 AT 11:23 AM

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