i have a 92 camaro 3.1 v6
The car runs rough and i went to adjust the timing. Well even after setting it to 10 degree btdc(factory) the car still ran rough. I read codes and got...

15-coolant sensor(which was replaced recently)
33-Digital egr system
42-Elec. Spark Timing
43-Elec. spark control

any ideas why all these codes are showing up? and each code has defective ecm as one of the causes. Is there a simple way to test ecm? thanks for any help

 

did you reset the ecm and erase the codes after setting the timing? when you set the timing it will throw the code 42 or 43 i cant remember which.

 

Unplug the battery for 5-10m plug it back in then see what codes if any are still present. Unless the 3.1s are OBD II in which case you need a scanner to manually reset the ECU.

 

odbII didnt start untill 95-96 in most cases

 

its obdI, thanks for all the help. Ill try resetting it over night. Ill bring results tomorrow. Thanks again.

 

True, kind of forgot that till you mentioned it, lol. Btw that thing rdy for the 1/4 yet?

 

it would be lucky if it moved 1/4 inch at the moment...need rubbers

 

Let's clear up some misinformation here. Don't know where you got the definition of code 33, but it's wrong...
Code 15, IIRC, is temp sensor failure low (Generally puts the ECM's sensed engine temp at -130*F)
Code 33 is MAP (manifold pressure sensor) failure high
Code 42 sets when setting ignition timing, but also means a failure on the EST bypass line.
Code 43 is a spark control problem, somewhere between the knock sensor and the ECM. The knock sensor is on the passenger's side of the block, screwed into the coolant drain just above the starter. Make sure it's connected and that the connector and wire are in good shape and not melted and shorted to the exhaust.

An EGR failure, be it digital or vacuum, is code 32... Reset your ECM by disconnecting the battery, for the idle relearn procedure, and let the ECM learn how to play with the new part(s). Then post up any continuing codes.

 

i reset the ecm, nothing changed. Is there something that can cause all these codes? none of these codes were on the car before i replaced the fuel pump. And thanks for the clarification on the codes!

 

Same trouble codes? Or different ones?

 

same codes....
Heres what is going on.
1. Rough Idle
2. Rough acceleration
3. Stalling at idle
4. Loss of gas mileage
I believe it to be my EGR, is there any easy ways to test it?
thanks!

 

Don't do ANYTHING with the EGR until you get rid of the trouble codes. IF the EGR is stuck open at times, it's only magnifying the problem. Not to mention that if you get a new one, you've probably wasted about $200...

Code 15: CTS temperature low (generally -130*F): Generally dumps fuel into the cylinders as the ECM thinks the engine is extremely cold and dumping fuel provides easier starting due to the extremely dense air charge. May cause hard start, poor economy, black exhaust with carbon ***** shooting out the tail pipe (best seen in snow). Check the black wire for being broken if the sensor has already been replaced by checking with a test light connected to the battery. Test light should light when the ignition is turned on. If not, there is either a broken wire or the ECM is bad.
Code 33: MAP sensor voltage high, indicating low engine vacuum: Generally dumps fuel into the cylinders as the ECM thinks there is high internal manifold pressure and/or the engine is at WOT (when engine vacuum is at its lowest). Same symptoms as above. Same test as above, but also check for a voltage difference between the gray and green wires. If the voltmeter reads 0 (ignition must be on again or still), there is a short in the signal circuit, indicating either a broken wire or a bad ECM. The meter should read 5V on this second test.
Code 42: Spark timing circuit error: Generally set with the set timing connector disconnected as this is a normal function. However, with the connector connected and the wire grounded somewhere along the line, the ignition module will go into EST mode but the ECM will not be controlling the spark timing. So, as a result, economy and performance will suffer, as the ignition module isn't as accurate as the ECM in controlling the timing without external sensor input, and the spark timing will always be on base timing at idle.
Code 43: Knock sensor circuit error (spark control circuit error): Only parts to fault here are either the sensor, the ECM, the MEMCAL, or the wire between the sensor and the ECM. There is no filter module like on the V8 cars, it's within the MEMCAL itself. Disconnect the sensor with the ignition on and engine off, check for around 5V at the terminal inside the connector. And then disconnect the ECM and check the wire (still disconnected from the sensor) for both shorts to power and ground. If the wire is not shorted, then the ECM needs to be replaced. Also check the resistance of the sensor between the terminal and the engine block (the terminal in the sensor, not the connector), should be between 3300-4500 ohms. If incorrect, the sensor is bad.

Seeing as how the same codes came back, first thing I would do is get a junkyard ECM. A lot of times, multiple codes indicate the ECM is toast. If it doesn't work, you can either keep it as a spare or sell it.