Hello everyone,

Due to some unexpected bills, I have to put the rear end on hold for a week or two.

However I am taking the time to try and get my engine running a little better...

Here are the codes and their descriptions from the scanner I used:

43
Electronic Spark Timing (EST) circuit - low voltage detected
Electric spark control (ESC) circuit problems

45
Rich exhaust indicated (left side on dual oxygen models)

53
Calibration package chip or ECM fault or Oil temperature sensor fault/ low engine temperature; faulty or missing prom/calibration package chip; ECM problem
System voltage high for a long period of time

55
Electronic control module (ECM) Fault
or oxygen sensor circuit fault or EGR solenoid #3 failure or fuel lean monitor

I'll be honest, I don't even know where to start to tackle these...

Any help at all would be wholly appreciated. Thanks!

Also, my fans turn on automatically when the key is in the on position. I tried replacing the relay and that didn't do it. I can tell the PO definitely had some fun with wires...

 

What are you working on ?

 

Well I believe my engine is a bit underpowered right now, and I suspect it has something to do with either the computer itself, or actual discrepancies between sensors and the like. I suppose I am due for a spark plug change, though I hadn't had some of these issues before the accident.

The biggest thing I notice is starting the car can take 2 or more tries sometimes, so that leads me to believe something timing related, which brings my attention to code 43... But I don't know how to trouble shoot these particular issues... I had figured the issue was stemming from the ECM, as the PO either replaced the original memcal, or the entire ECM. I did try a different ECM with the current Prom, however the light didn't go away... Though I didn't read that codes during that particular test.

 

 

Check the grounds at the back of the cylinder heads. Some of those codes are referring to the O2 sensor voltage being low (lean), and the ECU has an O2 sensor ground circuit that must be good or those kinds of codes can be the result.

Same with the timing signal - low voltage codes may be the result of a poor ground path for sensor voltages.

GD

 

Where are these grounds exactly? I cleaned up and checked everything I could see...

I also began checking the resistances of the injectors, but I can't seem to figure out how to measure the resistance on the relays or sensors... Any tips for a novice?

 

They are on the back of the cylinder heads. Next to the firewall.

You can't check every sensor using resistance and you don't have any codes pointing to any specific sensors. The codes are pointing to the O2 (resistance checks are useless for an O2) voltage.

Check the grounds first.

GD

 

Whenever you have multiple, somewhat related, but otherwise random-seeming symptoms, ALWAYS look for a common cause of them all. You could waste no telling how much time "troubleshooting" each one, such as with a factory service manual "troubleshooting" chart, and accomplish EXACTLY NOTHING.

In this case, a faulty ground would be the first suspect; closely followed by faulty power. The actual fault might take the form of a loose bolt, a corroded connection, a broken wire, or chafed insulation; ANY of this kind of failure can produce intermittent symptoms all over the system. It is NOT that any number of sensors randomly all failed AT THE SAME INSTANT; it is not that the ECM (although it is "common" to all the symptoms) suddenly developed all these various faults; NOT NOT NOT NOT NOT.

"Troubleshooting" in the sense of those "charts" is based on the idea, appropriate to a NEW CAR STILL UNDER WARRANTY (which is what FSMs are written for, NOT antique hoopties with a million miles and however much hackage accumulated on them) was working perfectly fine up until the very moment that ONE THING broke; and the "chart" is designed to help you zero in on that ONE THING. They are NOT designed as some kind of ultimate authority on every possible thing that can go wrong with a car over its entire useful life; or as these cars are now, after about 3 of what the factory considers the "useful life".

You check resistance with an ohmmeter: you hook it up to the 2 terminals and it tells you what the resistance is. Keep in mind, this is alot like having a GPS device that gives you PERFECTLY ACCURATE 3-dimensional coordinates for WHERE YOU ARE, but doesn't come with a database of roads, places, addresses, and so on, to tell you WHERE TO GO. You can measure resistance all day long, and aside from direct shorts and open circuits, you would have no idea whether it's right or not. Personally I think you'd be wasting your time with that, at least with using it as your first pass at investigating your problem. A half-dozen sensors relays solenoids whatever, didn't just ALL THE SUDDEN ALL AT ONCE develop incorrect resistance. If you had ONE that was suspect, then yes, maybe; but not in this situation.

The ECM rarely gets "destroyed" by a faulty driven device. Its outputs have current-limiting circuitry to prevent them from being burned up in all but the most heinous circumstances. More than likely there's nothing wrong with it. Direct your attention elsewhere.

See my signature for helpful advice.

 

Well, I finally took the bolt off the back of the head and cleaned everything up, but to no avail. I went out and bought a new O2 sensor and Im gonna try popping that in tomorrow morning to see if I can't get rid of at least one code.

Which brings me to another few questions...

Where should I check next?

What's the best personal use OBD1 reader available, and how much would it cost to get me set up for programming my own chips? Or reprogramming a current one?

When you say faulty power, I do notice my volt gauge sometimes drops to where it looks like its only on battery power, and then it will pop back up to 13v or so...

I thought this might be a faulty gauge, and I checked the power coming out of the battery, and it read 13.4 or so. But the problem is pretty intermittent.

Would that be an alternator issue? Or could that be a wire somewhere causing mayhem?
​​​​​​​

 

So I replaced the O2 Sensor and three of the codes went away. Instantly better response and startup time, but I had a hell of a time getting it out, I tell you what.

All that remains is 43...

Where should I continue to look for this?

I guess I am going to replace the knock sensor as well and see what happens.

Hopefully that doesn't give me as much trouble.

Edit: Well when I started her to go to the parts store, the CEL never came on. Hasn't come back on all night...

The O2 Sensor was literally the cause of all my problems lol.

It still feels like there is a loss of power, although much better than it was, but at least there are no blatant codes.

Thanks for all the help guys.

Just for anyone who might want to look this up in the future for any reason.

This is the location of the O2 Sensor on an 88 305 TPI Camaro

Right where that special 22mm O2 Socket is, I would suggest getting the right tool, and you will need some extensions, as well as some PB Blaster if it was anything like mine.