sportblazer350
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- Apr 19, 2013
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so my 1994 Blazer 5.7l was due for a major tune up. replaced: spark plugs and wires, dist cap and rotor, then had problems with idle and very rough idle at start up that almost faded away after the engine warmed up. So- replaced the egr valve, egr solenoid, egr vacuum line, another vacuum line, iac valve, and the coolant temp sensor. also replaced the dist pick-up coil and the coil itself.
Then a few days later: the horrible idle at start up returned! engine shakes bad, exhaust is blue and smells funny, check engine light comes on and off, fluctuating idle. so I took my Blazer to another shop, and here is what they did:
- found the new vacuum line to the EGR valve was a loose fit, so he heated it to shrink it and made a tighter fit; adjusted the throttle position sensor (did not know that was possible??), and found the throttle cable had a bit of a kink causing some binding.
results: this old Blazer with 254,000 mile purrs like a kitten!!
just a head's up for any out there with the same problem with a cold start idle. it's always either a vacuum leak and/or a sensor whenever this engine runs poorly.
Then a few days later: the horrible idle at start up returned! engine shakes bad, exhaust is blue and smells funny, check engine light comes on and off, fluctuating idle. so I took my Blazer to another shop, and here is what they did:
- found the new vacuum line to the EGR valve was a loose fit, so he heated it to shrink it and made a tighter fit; adjusted the throttle position sensor (did not know that was possible??), and found the throttle cable had a bit of a kink causing some binding.
results: this old Blazer with 254,000 mile purrs like a kitten!!
just a head's up for any out there with the same problem with a cold start idle. it's always either a vacuum leak and/or a sensor whenever this engine runs poorly.
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