Car runs like crap, shows codes 21 and 42
05-25-2017, 01:31 AM
#1
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Car: Camaro Iroc-Z -89
Engine: 350 TPI
Transmission: Automatic
Car runs like crap, shows codes 21 and 42
Hello,
Some weeks ago I replaced the distributor cap, rotor and coil on my '89 Camaro 350 TPI. Before this it ran fine. When starting it up it ran very poorly and has been since. Feels like it's running only on a few cylinders, hardly responding to throttle. When keeping the throttle halfway down, it will run but again poorly (undrivable). I've swapped back to old ignition parts with no difference. Tried to start without EST connected -no difference. Now I'm lost.
Last time I was tinkering I managed to get two trouble codes -21 and 42. I've read what they mean (21 - high voltage etc. on TPS; 42 - EST problems). Can one of these set off the other? Has anyone experienced something similar?
I have tried the following:
Checking spark plug cable order - OK
Timing is unchanged 6 degrees BTDC (no EST) - OK
Spark to plugs - OK
Fuses (from what I can see/find) - OK
Pressure in fuel rails 45 PSI - OK
Br,
Per
Some weeks ago I replaced the distributor cap, rotor and coil on my '89 Camaro 350 TPI. Before this it ran fine. When starting it up it ran very poorly and has been since. Feels like it's running only on a few cylinders, hardly responding to throttle. When keeping the throttle halfway down, it will run but again poorly (undrivable). I've swapped back to old ignition parts with no difference. Tried to start without EST connected -no difference. Now I'm lost.
Last time I was tinkering I managed to get two trouble codes -21 and 42. I've read what they mean (21 - high voltage etc. on TPS; 42 - EST problems). Can one of these set off the other? Has anyone experienced something similar?
I have tried the following:
Checking spark plug cable order - OK
Timing is unchanged 6 degrees BTDC (no EST) - OK
Spark to plugs - OK
Fuses (from what I can see/find) - OK
Pressure in fuel rails 45 PSI - OK
Br,
Per
05-25-2017, 08:54 AM
#3
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Car: 87 GTA, 88 GTA, 92 TA, 72 RS SS
Engine: 350, 350, 305, 396
Transmission: T56, 700r4, 700r4, T56
Axle/Gears: 3.42, 3.23, 3.23, 3.73
Re: Car runs like crap, shows codes 21 and 42
I agree with tootie pang, the firing order is not right or you damaged the plug wires in the process of changing parts..
05-25-2017, 03:28 PM
#7
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Car: Camaro Iroc-Z -89
Engine: 350 TPI
Transmission: Automatic
Re: Car runs like crap, shows codes 21 and 42
Thanks for your ideas, I'll look for a bad ground. Possibly I could have caused something while tinkering. Will let you know how it proceeds.
Br,
Per
Br,
Per
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05-28-2017, 05:26 PM
#8
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Car: 1985 Yellow Iroc Z w/LS interiors
Engine: 305ci 5.0L
Transmission: 700r4
Re: Car runs like crap, shows codes 21 and 42
Sorry not to high jack the threat but in the same line ,any one have the ground diagram for the same car 89 Iroc? I'm helping a friend to chasing the same problem but i have been out of the TPI sine close to 15 years.