LT1 diagnostic help
04-21-2009, 12:47 PM
#1
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LT1 diagnostic help I have a 128k '94 Camaro Z28 A4 here that belongs to one of my wifes co-workers. Its has PS headers, decat, borla CB and I "think" a very mild cam. He bought the car this way so info is very hard to come by.
Symptoms:
Runs very rich (heavy black smoke on hard accel)
Pops & backfires through the exhaust when you get on it
NO POWER, it will not even spin the tires.
The owner claims to have replaced the Opti, wires and plugs within the last 8 mo. EDIT: The o2's as well.
I hooked up a scan tool, Modus and paper clip all to the ALDL and can not check for codes. The engine will go into field service mode (fan on & CEL flashing) but will not flash any codes. I just get a rapid CEL flash. The Modus can not communicate with the ECM or the ABS module. I checked all the fuses and none appear to be blown.
Ideas? I am trying to help this kid out so any help would be great.
Symptoms:
Runs very rich (heavy black smoke on hard accel)
Pops & backfires through the exhaust when you get on it
NO POWER, it will not even spin the tires.
The owner claims to have replaced the Opti, wires and plugs within the last 8 mo. EDIT: The o2's as well.
I hooked up a scan tool, Modus and paper clip all to the ALDL and can not check for codes. The engine will go into field service mode (fan on & CEL flashing) but will not flash any codes. I just get a rapid CEL flash. The Modus can not communicate with the ECM or the ABS module. I checked all the fuses and none appear to be blown.
Ideas? I am trying to help this kid out so any help would be great.
04-21-2009, 12:51 PM
#2
I have a 128k '94 Camaro Z28 A4 here that belongs to one of my wifes co-workers. Its has PS headers, decat, borla CB and I "think" a very mild cam. He bought the car this way so info is very hard to come by.
Symptoms:
Runs very rich (heavy black smoke on hard accel)
Pops & backfires through the exhaust when you get on it
NO POWER, it will not even spin the tires.
The owner claims to have replaced the Opti, wires and plugs within the last 8 mo. EDIT: The o2's as well.
I hooked up a scan tool, Modus and paper clip all to the ALDL and can not check for codes. The engine will go into field service mode (fan on & CEL flashing) but will not flash any codes. I just get a rapid CEL flash. The Modus can not communicate with the ECM or the ABS module. I checked all the fuses and none appear to be blown.
Ideas? I am trying to help this kid out so any help would be great.
Symptoms:
Runs very rich (heavy black smoke on hard accel)
Pops & backfires through the exhaust when you get on it
NO POWER, it will not even spin the tires.
The owner claims to have replaced the Opti, wires and plugs within the last 8 mo. EDIT: The o2's as well.
I hooked up a scan tool, Modus and paper clip all to the ALDL and can not check for codes. The engine will go into field service mode (fan on & CEL flashing) but will not flash any codes. I just get a rapid CEL flash. The Modus can not communicate with the ECM or the ABS module. I checked all the fuses and none appear to be blown.
Ideas? I am trying to help this kid out so any help would be great.
Usually a flashing SES signifies a misfire detected, but I didn't know if the '94's had misfire detection or not. That could explain all of the symptoms above. You need to find out what the code(s) are.
04-21-2009, 12:56 PM
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I cant get into the ECU to read the codes. Like I stated I have tried everything from a paper clip to a $13k Snap on Modus. The ECU and even the ABS system arent communicating via the diagnostic port (aka ALDL).
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04-22-2009, 04:15 PM
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I bought one of these seems to work ok http://cgi.ebay.com/ebaymotors/Autox...1%7C240%3A1318
04-22-2009, 11:44 PM
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94 cars with the obd1 style plug you cant flash codes out with a paper clip in the A&B and i have yet to find an adapter for my obd2 scanner. I could also use some help on this. Is there a way to adapt the obd2 plug to the ALDL using jumper wires?
