Please Help !!!!!!!!!!!!
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Junior Member
Joined: Oct 2001
Posts: 29
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From: pompano fl
Please Help !!!!!!!!!!!!
I am having problems with my 1986 camaro 305 TPI..
Every time I'm driving my car starts staling . Then I rev the engine and the car hesitates but it does not stall. And the service engine light flickers . But the car hesitates only on low rpms. but the thing is when the service engine light is not on i have this problem but when the service engine light is on the car runs fine . ontill it starts all over again and i have to go through that whole process again. I am getting codes 42,43,and 44 some body please help me thanks......
Every time I'm driving my car starts staling . Then I rev the engine and the car hesitates but it does not stall. And the service engine light flickers . But the car hesitates only on low rpms. but the thing is when the service engine light is not on i have this problem but when the service engine light is on the car runs fine . ontill it starts all over again and i have to go through that whole process again. I am getting codes 42,43,and 44 some body please help me thanks......
Member
Joined: May 2001
Posts: 156
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From: SoCal
code 42- EST circuit open or shorted to ground
code 43-EST circuit- low voltage detected
code 44-o2 sensor indicates lean exhaust condition after 1-2 minutes of engine running
im not very good with the est, id call the dealer and see what they recommend, andpossibly take it in, but its causing your engine to run lean.
code 43-EST circuit- low voltage detected
code 44-o2 sensor indicates lean exhaust condition after 1-2 minutes of engine running
im not very good with the est, id call the dealer and see what they recommend, andpossibly take it in, but its causing your engine to run lean.
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Joined: Jan 2000
Posts: 19,658
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MTH,
Check the electrical connectors at the distributor and the EST module. Don't forget the HEI amplifier/switch module in the base of the distributor. Unplug the connetors one at a time, inspect the individual connectors and wires, clean if necessary, and firmly reconnect them:
Take a close look at the ground and harness connections at the ECM, and unplug an reseat them several times to clean the connections. Check the ground straps from the engine to the chassis. There is one on the rear of the right head that is necessary for a good ECM logic ground, and may affect a lot of sensor inputs if it is marginal. Remember to check and clean the batter connections and ground distibution connection node on the inner fender. Remove, clean, apply a little anti-seize, and reassemble.
Also consider the possibility of two separate problems. It's possible that the oxygen sensor is over 30,000 miles old and cannot report the correct data to the ECM. The noraml failure mode is a loss of signal, or lean indication, so if the engine has smelled a little rich lately you might want to consider a new sensor.
The reason that the engine runs better when the MIL lamp is on is that the ECM reverts to backup fuel and spark tables when it can no longer rely on sensor inputs to monitor the engine. When the lamp is on, you're in Backup Fuel mode. If it runs good in that state, there can't be a lot wrong with the engine, only the control system. Finding the problems is easier if you have scanned for the error codes and take the message they are sending.
Check the electrical connectors at the distributor and the EST module. Don't forget the HEI amplifier/switch module in the base of the distributor. Unplug the connetors one at a time, inspect the individual connectors and wires, clean if necessary, and firmly reconnect them:
Take a close look at the ground and harness connections at the ECM, and unplug an reseat them several times to clean the connections. Check the ground straps from the engine to the chassis. There is one on the rear of the right head that is necessary for a good ECM logic ground, and may affect a lot of sensor inputs if it is marginal. Remember to check and clean the batter connections and ground distibution connection node on the inner fender. Remove, clean, apply a little anti-seize, and reassemble.
Also consider the possibility of two separate problems. It's possible that the oxygen sensor is over 30,000 miles old and cannot report the correct data to the ECM. The noraml failure mode is a loss of signal, or lean indication, so if the engine has smelled a little rich lately you might want to consider a new sensor.
The reason that the engine runs better when the MIL lamp is on is that the ECM reverts to backup fuel and spark tables when it can no longer rely on sensor inputs to monitor the engine. When the lamp is on, you're in Backup Fuel mode. If it runs good in that state, there can't be a lot wrong with the engine, only the control system. Finding the problems is easier if you have scanned for the error codes and take the message they are sending.
