I just bought a 1989 Chevy 4WD 350 auto pickup K/model. The engine had a terrible miss so I replaced plugs, wires and another computer. It now runs good for city driving but as soon asI get up to about 35 mph there is yet a miss. My speedometer isn't working. Does the speedometer have to work for the computer to work at a higher speed. Any info would be appreciated.
Thanks, Joe
I don't believe the speedo could cause a ECU malfunction. Replacing the ECU was a waste of money (support your local parts dealer). You did'nt mention changing the cap or rotor (inspect first and check) before you support your local parts house some more. Perform a resistance check on ignition coil as it may be breaking down under load . Unless you're sure that it's not missing at any engine speed then you may wanna hook up a vacuum guage and/or a compression tester.
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