350 running rich in open loop
08-02-2018, 06:21 PM
#1
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Car: 92 Camaro RS 25th aniversary editio
Engine: 305 tbi
Transmission: auto
350 running rich in open loop
Looking at buying a 88 iroc but have a question. The owner says it runs rich on start up when in open loop but runs fine when it goes to closed loop. Says blue smoke and spits and sputters. His mechanic says it needs a new computer. Any thoughts on what this might be and if it is an easy fix? Don't want to buy if there is something major wrong.
08-02-2018, 08:53 PM
#2
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Re: 350 running rich in open loop
Burning oil and leaky injector(s) possible.
A new computer?
A new computer?
08-04-2018, 05:56 PM
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Car: 92 Camaro RS 25th aniversary editio
Engine: 305 tbi
Transmission: auto
Re: 350 running rich in open loop
He says it only does it when its hot outside. Runs fine during cold weather.
08-04-2018, 07:16 PM
#4
Re: 350 running rich in open loop
Probably needs valve stem seals. Blue smoke would be oil, not fuel.
Cold vs. Hot might be an issue with the coolant temp sensor or the cold start injection system.
Not likely to be the computer if it runs good in closed loop. How did he come to this conclusion? It is typically the mechanic that needs to be replaced not the computer when such diagnoses are thrown around without details on how this conclusion is reached. Now if the mechanic said that the coolant temperature reading from the ECM didn't match the sensor resistance and that the wiring had been ruled out I might be inclined to look closer, but blaming "The Computer!" is usually a cover story for not knowing how to properly diagnose it.
GD
Cold vs. Hot might be an issue with the coolant temp sensor or the cold start injection system.
Not likely to be the computer if it runs good in closed loop. How did he come to this conclusion? It is typically the mechanic that needs to be replaced not the computer when such diagnoses are thrown around without details on how this conclusion is reached. Now if the mechanic said that the coolant temperature reading from the ECM didn't match the sensor resistance and that the wiring had been ruled out I might be inclined to look closer, but blaming "The Computer!" is usually a cover story for not knowing how to properly diagnose it.
GD
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