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John, Master A.S.E Automotive technician
Category: Chevy
Satisfied Customers: 9176
Experience:  A.S.E MasterTechnician A1-A8 w/L1,38 years experience General Motors Master Technician
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92 chevy s10: runs rough..runs fine..injectors on throttle body

Customer Question

92 chevy s10 4.3 throttle body new fuel pump new map sensor starts randomly runs rough like running real rich until you keepgiving gas pedalsmooths out and runs fine then after you shut off may not start again for quite some time when not starting it has spark but I see no fuel flow from injectors on throttle body with air cleaner off 140000 miles
Submitted: 8 years ago.
Category: Chevy
Expert:  John replied 8 years ago.


Start with scanning the computer data list & look at the data parameters.Check for failure codes.In 92 there is not much onboard diagnostics.The injector pulse ,which you do not seem to have when starting,is commanded by the ECM when conditions are proper.One is clear flood mode-achieved by tps at 100%-ECM will stop injector.Make sure fuel pressure to engine is 12-17 & holding.I believe you have a bad ECM or no fuel pressure on start up.Check fuel pump relay,usually you can here it cycle with the ignition switch on/off, when under the hood.