will cruise at 65 or 85 but shudders and stalls at 75

1991 CHEVROLET CORSICA
160 MILES
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CIROCCO
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  • 2 POSTS
3.1L v6 replaced egr tps iac catalytic converter and crank position sensor. catalytic converter was plugged and back pressure blew seals out of egr.
Mar 8, 2012 at 11:59 PM
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DRCRANKNWRENCH
  • CAR REPAIR CONTRIBUTOR
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I am going to give you a diagnostic walk though for your situation. Just follow the link below;

https://www.2carpros.com/articles/engine-stalls
Mar 9, 2012 at 1:25 AM
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CIROCCO
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Why does leaving the gas cap off cure the problem?
Mar 24, 2012 at 9:00 PM
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DRCRANKNWRENCH
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You have a problem with the vent on the fuel tank. You can try getting a new fuel cap and tight will hopefully fix it. If not, you will have to look into clearing the gas tank vent as it has become cloged somehow. This may also be happening in the EGR pipe system near the exhaust and causing the same situation. You may also have a larger blokage in the exhaust itself at the catalytic converter, but leave that aside for now.
Check EGR lines and get a new fuel cap. Do each fix one at a time to see which one cures the problem.
Mar 25, 2012 at 3:55 AM