Went to have my car smog today and in the initial test it failed in two areas. First was in the ignition timing and second in the emission (CO % max reading s/b 0.58 car measured at 0.68). Brought it to a shop to check timing. Timing was sent based on smog specification (6 degree BTC). Now the car runs like it has no power and check engine light came on. Pull codes and codes 15, 36 and 42 came up. Thought maybe shop forgot to reset computer, so clear codes and started car up again. Check engine line came on again. Check code and code 42 came up. Clear code one last time and started car up came....code 42 again. Based on both Smog Test only center and car repair shop the timing is on spec. What could be causing a code 42. Car was running fine before having to smog.

 

Check to see if the timing bypass connector has been reconnected after the timing was set. It is the tan/black wire near the A/C condenser.

 

Re-check and all wires were re-connected. Any other suggestions.

 

Check all the connections at/in the distributor, including the HEI switching module.

IIRC, the '89 does not have a separate ESC, since I believe it was incorporated into t6he ECM about that time. I may be wrong, and you might find an ESC module on the firewall behind/near the brake power booster. If so, check the connector there as well.

You can also check the connection and condition of the detonation sensor just above the starter. If it is disconnected or damaged, the "42" will not go away.

 

Yes there is a seperate ESC module on the 89 camaros and it is located on the driver side firewall behind the fuel pump relay, MAF power relay, & MAF burn-off relay.

 

Thanks for the suggestions. The problem appeared to be the Module in the dizzy. Took the module out, clean it off, greased it and put it back on the dizzy and the code 42 went away. But what getting me is this is the three time in the past three months I have problems with either the module or dizzy. About two months ago we replaced both the dizzy and module. We purchased both parts as one unit from Auto zone. A month later the car completely stall on the freeway. Turn-out to be the same parts again. Since there was a life time guarantee, brought both parts back to Auto zone for a replacement. That was on 6/24. Now more than a month later the same part (module) is having problems again. The only difference is it did not go completely bad. I think I need to just replace the module. Took the car out a few minutes ago and stalled on me down the street from my house. It started right back up but I did not want to take the chance of stalling again. Don't get why the car keep having the same problem with either the dizzy or the module. I'm either getting bad parts from Auto zone or something causing the module to burn out.

 

My car has the 42 and 43 code. I can make a pass down the track one time and it will run. The next time it will slow down about a .10 in the 1/8 mile. I have narrowed it down to the module. I rebuilt the dist. with a module and a pickup from autozone. Module lasted two weeks. Put a new Holley module in. It lasted about a week. Just would like some info as to why the module is getting fried?

 

I wish I could help with your problem. Seems like no one here in the forum can help either. My car will run great for a few weeks then service engine light would come one\. Just went out to the store and before I could get home service engine light came on. Check and read codes 15, 36 and 42. I cleared the code and just 42 came back. Just do not get this. Car pass smog test yesterday with no problems. Can anyone in the forum answer the question as to why module keep burning out.

 

did you replace the module, or did you clean, and put it back in. If it is bad, many times after heating up (like driving it uptown and back) the module will start screwing up.

 

Have done both. The module has been replaced twice. The last time shop clean and regreased module. Code 42 was gone. Now code is back again but this time codes 15 and 36 is showing along with code 42. If it's the module again, something is causing it to burn out or keep getting a bad module from Auto zone. Like the other guy, module seem to last between 2 weeks to 1 month before problem reappears. I can keep replacing the module but really not solving the problem.

 

Your code 15= Coolant Temperature Sensor circuit (low temperature indicated) & code 36 = MAF Burn-off circuit. I don't know if you have seen it or have done a for it, but there is a trouble shooting chart for all three of your codes that I have posted on the board several times in the past few months. I have posted them for the 2.8L, TBI, & TPI engines.

 

Are you using an aftermarket coil? Many higher current coils will kill an HEI switch quickly, since the coil primary current exceeds the HEI switching transistor ratings.

 

I'm not sure if its an aftermarket coil. The coil was replaced by shop I brought the car to about two months ago. The coil was replaced twice on the vehicle. What is troubling is that we have replaced almost everything in the ignition area. The wires, rotor, spark plugs, coil (twice), distributor (twice), cap, and the module (twice and possibly a third time if it needs replacing again). This last time the shop (where the smog check was done) took the module out and clean it off and regrease. The code went away long enough for the car to pass smog but came back three days later. This weekend we plan on again examining all connectors to and from coil and distributor (maybe even replacing the connectors, if necessary) along with having the module tested. We'll check the coil to see if maybe it's causing the problem with the module burning out. If this does not work......well I'll have an Iroc for sale.

 

I found that the throttle position sensor was bad and that caused the computer to have a hard time with the timing. Hope this helps. I didn't get any reading from mine at all.