1988 Chevy Silverado intermitent miss/ poor performance

153,000 MILES • V8 • 4WD • AUTOMATIC
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BUBBA78
  • MEMBER
  • 2 POSTS
ok...i just bought a 1988 chevy half ton four wheel drive single cab long box. it has a 5.7/350 in it out of a 1987 with 50k miles on it. when i bought the truck it was extremely out of time, i re-timed it with a timing light.
it starts really cold like a carbureted motor would..it is throttle body injected. when driving down the road it has a slight miss, but when it is warm the check engine light comes on and it wants to stall when trying to hold a speed. when accelerating rapidly it acts somewhat fine. i have replaced the fuel pump, O2 sensor, temp sending unit and sensor, fuel filter, cleaned injectors, new cap rotor and coil, plugs and wires.
Oct 23, 2009 at 2:26 AM
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JDL
  • ✓Experienced Mechanic
  • 16,098 POSTS
Welcome, if the cel is on, there should be some code/s, did you check for codes?
Oct 23, 2009 at 2:35 AM
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BUBBA78
  • MEMBER
  • 2 POSTS
i checked it for codes and i had codes 42, 43, and 45. i replaced the knock sensor and the ignition module...i was going to try a new esc module today. after replacing the knock sensor when the SES light comes on it will hold a speed, it still has a slight miss. also since i have replaced the egr valve and solenoid, and map sensor. it didnt give me this problem until the ignition in the column went out and it wont shut off with the key so i wired a kill switch.
Nov 11, 2009 at 12:39 AM
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