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Discussion Starter #1
Hi all,

Just finished a lot of major maintenance on my 91 Spider: new Spruell motor mounts, gearbox mount, new muffler and tailpipe, new belts, three radiator hoses, new intake runners, fuel hoses, injectors serviced by Marren, oxygen sensor and more. I cleaned every electrical connection I could find and the battery is fully charged. The car performs well and the hesitation and thumping in the rear under acceleration are gone, but now when the car is hot the Check Engine light comes on (which it never did before). Turn the ignition off and restart the engine and all is well until I rev it to 3000 RPM, then its back on again. When I rev the engine cold, I do not get the Check Engine light.

I checked the malfunction codes and received 1-2-2-4: "Lambda sensor and/or wire assembly and/or E.C.U." I purchased the non-Bosch 3-wire sensor from IAP and had no trouble installing it as it plugged right in.

Any suggestions? I am new at this Alfa game.

Thanks in advance,

John
 

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Sorry I can't help, but I also just picked up a 1991 spider, how did you retrieve the fault codes?

Doug
 

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1224 indicates that the O2 sensor is not giving a reading. So not in range at all. Could be improper connections. Could be a faulty O2 sensor. Could be a broken/burned harness on the exhaust. Could be no power for the heater...so blown fuse. So in short....get out a Digital multimeter and see what the reading is from the O2 sensor...if there is one. Do this by leaving the O2 sensor connected to the car's harness...but slide in the red probe into the orange capped connector near the brake booster. Ground the other probe. Set DVM to DC Voltage in 1-.1 range. If you are getting proper readings (.2-.8) and it bouncing around....then you might have a problem elsewhere....extremely unlikely. Most likely you won't get any reading or a sub .2 reading.

Next check the heater wires. Two white wires in the black connector next to the orange capped connector. One is ground. One is 12V. Make sure that is the case with your multimeter.

My bet is that you will find the problem as being either the heater wire is not getting power...or maybe a short in the harness between the car's connectors and the O2 sensor.



Link for checking codes: http://www.alfabb.com/bb/forums/showthread.php?t=6089&page=1&highlight=check+engine+codes

Best Regards,
John M
 

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Discussion Starter #4
Thanks for getting back so quickly, John. I don't have a digital voltmeter, only an older analog type. I do get 12V between the two wires for the heater (with the O2 sensor disconnected) and also 12V between one of the wires and the engine. When I measured the voltage between the orange connector and ground (with the O2 sensor still connected and just the black rubber cap slid out of the way) I get what appears to be about .2 volts with a steady reading. But it is hard to tell with the analog meter, and my finest scale is 0-15V.

Everything is plugged in OK and the harness is not burned nor touching the exhaust header, as I had cable tied it to the firewall and used the bend-over metal clip there.

Any other ideas?

Thanks again.
 

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Get a digital meter. Less than $20 anywhere. REQUIRED for any troubleshooting of computer controlled cars. That is, basically, any car not running point ignition, and made after the late 70's.
 

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Discussion Starter #6
Update on the O2 sensor. Bought a digital multimeter and everything checked out to spec as John described. Called IAP where I bought it and they concluded it might be a faulty sensor. Sent me a new one no charge and I finally put it in tonight. Went out and drove the car hard and no check engine light appears. Problem solved and many thanks to John and the boys at IAP.
 

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Congrats John. Sounds like you got it licked!

Best Regards,
John M
 
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