# 92 Eclipse with severe engine stumble

**URL:** <https://community.cartalk.com/t/92-eclipse-with-severe-engine-stumble/40603>\
**Category:** Maintenance/Repairs\
**Tags:** eclipse, mitsubishi\
**Created:** [December 10, 2009, 10:55pm UTC](https://community.cartalk.com/t/92-eclipse-with-severe-engine-stumble/40603 "2009-12-10T22:55:36Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![OldArmy](https://avatars.discourse-cdn.com/v4/letter/o/c2a13f/32.png) [@OldArmy](https://community.cartalk.com/u/OldArmy)\
**Post date:** [December 10, 2009, 10:55pm UTC](https://community.cartalk.com/t/92-eclipse-with-severe-engine-stumble/40603/1 "2009-12-10T22:55:36Z")

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I have a 92 Mitsubishi Eclipse 4 cyl 1.8L with a SOHC, non-turbo, 5-speed manual. It has 165,000 miles on it and is well maintained. The car has developed a severe stumble when accelerating in 1st gear from a stop. It appears to be an lean air/fuel mix problem. I have cleaned the fuel injectors, and the fuel pressure regulator, replaced the PCV valve and fuel filter. I have also replaced plugs, wires, and distributor cap and rotor. I have also checked for obvious vacuum leaks. None of this maintenance has solved the stumble problem. The strange part is … if I start from stop in 2nd gear then there is no engine stumble. Car dives well after I get it started off the line. With this many miles on it I suspect there is some degree of blow-by but unsure how this would cause this 1st gear start-up stumble. I did not do anything with the mass air sensor or oxygen sensor since a failure in either of these would cause a rich air/fuel mix. The car does not have an EGR valve. Any ideas as to my next move?

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**Author:** ![OldArmy](https://avatars.discourse-cdn.com/v4/letter/o/c2a13f/32.png) [@OldArmy](https://community.cartalk.com/u/OldArmy)\
**Post date:** [December 11, 2009, 2:50pm UTC](https://community.cartalk.com/t/92-eclipse-with-severe-engine-stumble/40603/2 "2009-12-11T14:50:04Z")

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Additional info / update … yesterday I spray cleaned the throttle body and added an additional bottle of STP fuel injector cleaner to the gas and 4 cyl Engine Renew additive to the oil. This morning, with 20 degree temps, I took a short trip and again experienced the engine stumble but after a few miles the problem disappeared. This has happened before … severe engine stumble that disappears only to return sometime down the road, usually after a high speed trip on the interstate. Any ideas?