how do i fix engine from running rich and car from bucking ?

Asked by Mar 20, 2013 at 05:31 PM about the 1986 Pontiac Fiero SE

Question type: Maintenance & Repair

jus t rebuilt 1986 4 cyl fiero engine. after reinstalling the engine is running rich and the car bucks as you apply the gas, i also get a oxygen sensor code . have replaced oxygen sensor and still get code, still runs rich and still bucks. i am not driving car at this time. any ideas .thanks

2 Answers


check egr valve


Wouldn't think a faulty egr would be to blame... Mine is blocked of and runs fine and before would leak frequently causing it to rapidly increase rpm... check injector for even spray pattern... maybe throttle position sensor... or maybe MAP sensor... also check all vacuum lines as a vacuum leak may make the engine think it's getting more air than it actually is.

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