My 1992 Chevy Lumina 3.1 starts very rough; you have to press on the throttle to start it and it sputters - almost dies - in gear.

I put a new fuel pump in a couple months ago and today I put a new fuel filter in, filled it up with gas and put fuel injector cleaner in it. I also put a new thermostat in and that made it a little better but it still is very rough to start and sputters in gear.

What could be the problem?

  • Welcome to Motor Vehicle Maintenance & Repair! Commented Mar 24, 2018 at 17:26
  • Has the throttle body ever been cleaned? Has the air filter ever been replaced?
    – Al_
    Commented Mar 25, 2018 at 16:26

1 Answer 1


Whether or not T-stat replacement was indicated, that might have diagnosed your problem, even if by costly dumb luck. The only connection between Coolant recycling and fuel throttling would seem to be the ECT (engine cooling temperature) sensor. Indeed, a defective sensor has been shown to produce the symptoms you described, and I quote: Your symptoms are a dead ringer for a bad engine coolant temperature sensor (ECT). The computer is calculating an air/fuel mixture that is too lean. That's why pumping the gas pedal keeps your engine running. You can have a bad sensor even without a “check engine” light or trouble code Your source is: https://www.google.com/search?rlz=1C1PRFB_enUS483US483&q=chevy+coolant+temperature+sensor+symptoms&sa=X&ved=0ahUKEwiUmP71uYfaAhVJxFQKHasjDNEQ1QIIgAEoBg&biw=1024&bih=550&dpr=1.25

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