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How to read aldl log?

I don't think winaldl shows map voltage. at least not in the datalog and I'm not sure what the numbers are that it shows. I think something happened to my cable cause I couldn't pull any data last time I tried. I replaced the o2 sesnsor after I fixed the oil burning problem. I though for the heck of it getting another o2 sesnsor and putting it in. Its under warranty.
 
I checked the vacuum with a gauge and it pretty much stays at 21 no matter what rpm. So i guess the cat is okay. I'm wondering why the values for the map sensor vary so much?
 
21 and steady is great. But it should drop like a rock when you open the throttle, then at steady RPM come back a little.

I'm not sure how a vacuum reading can diagnose a cat?
 
EXHAUST BACKPRESSURE CHECKS
To diagnose a plugged catalytic converter, you can check intake vacuum or exhaust backpressure. To check intake vacuum, connect a vacuum gauge to a vacuum port on the intake manifold. Start the engine and note the vacuum reading at idle. Then increase engine speed to about 2,500 rpm and hold steady. Normal vacuum at idle for most engines should be 18 to 22 inches Hg. When the engine speed is increased there should be a momentary drop in vacuum before it returns to within a couple of inches of the idle reading. If the vacuum reading is lower than normal and/or continues to drop as the engine runs, it probably indicates a buildup of backpressure in the exhaust. Remember, though, that intake vacuum can also be affected by retarded ignition timing and valve timing. What's more, some engines are much more sensitive to small changes in intake vacuum than others, so checking backpressure rather than intake vacuum may give you a better indication of what's going on.
Click to expand...

http://www.aa1car.com/library/converter.htm

In other words, engine can't expel exhaust, it can't ingest air either, so decreased vacuum.

Also notes how to test backpressure, but IMO that's more difficult unless you've already got the gauge and a fitting that will adapt to the O2 sensor hole.
 
I'm really not sure where to go from here. I think I'm gonna order an ecu with the acsu prom. That will get me to a federal tune and see if that changes anything.
 
Its been awhile, but it is finally fixed. I went to the junkyard and got a computer with asdu prom and a map sensor. That solved the code 13, but I was still getting code 32 for egr, So i went back to the junkyard and pulled an egr valve off a suburban that had a asdu prom. It was the ...194 egr and I had a ...196. That fixed the code 32. Thank you to everyone for all the help, Ive never started a thread and had 7 pages of replies before.
 
well I drove for 2 days with no light and it came back. Here's what I've done since. It started running rough right off idle, I went through the troubleshooting procedure for the egr and discovered that the junkyard egr was bad. It would not release when it sensed backpressure, so it was opening up right off idle and making it run bad. I put the 196 egr back on and checked the egr passages and made sure they were clear and the were. Still got the code 32, so I found a new gm 194 egr valve on ebay for $30. Put it on yesterday but still threw a code today. I checked the codes and I have 13 and 32. When I was driving about 50mph the light came on and went off a few seconds later. Then at about 70mph it came on and stayed on. What ever is going on is killing my gas mileage. I'm averaging 11mpg with mostly freeway driving and a light foot. 3.42 gears and 31" tires. I would expect to get better than 11mpg. I'm guessing that the code 13 is coming on at 70 and staying on as I don't think the light will stay on for code 32. While the light is on I guess its probaly running really rich and not using any of the o2 sensor readings. Should I order a delco o2 sensor? it has a new bosch on it now.
 
I also suspected that the cat could be plugged, so I took it out and welded in a piece of pipe, the cat wasn't plugged but it was starting to come apart. I know my exhaust manifold gaskets are leaking, would that cause problems for the o2 sensor?
 
Exhaust manifold gasket leaks don't help if they are upstream of the O2 sensor.

Since that isn't a rich/lean error code, make sure the wiring for the O2 sensor is good.

You've seen this? http://coloradok5.com/forums/showthread.php?t=141717&highlight=troubleshooting

Bosch O2 sensors used to be considered junk, although mine is pretty old and seems to work ok. Experience for many has shown otherwise, as had testing at the time. You need to be careful around them though, you know about "silicone poisoning"? Apparently this is no joke, and silicone not marked "sensor safe" can kill them. "Also, the use of any silicone sealers in the engine, if not marked "sensor safe", or "low volatile" will also affect the O2 to the point of being inoperative!" (from http://www.fierofocus.com/articles/tt-o2_sensor.html )
 
If you have an exhaust manifold leak, that could cause it to be running poorly.

I recently swapped to larger corvette manifolds trying to get rid of a pinging problem. After the swap, the pinging went away and I got noticably better engine performance overall. I have a hard time believing the difference was only from larger manifolds and that I likely fixed an exhaust leak as well.
 
One thing you might want to look for is that the wiring harness, running down the driver side frame rail, is not rubbing against the frame rail and grounding out. Thus causing all kinds of fault codes to trigger.

GM trucks in your trucks year range where known for this. I had two of them with this problem. I cured the problem by just throwing some new wire shielding on the wire loom running from the firewall junction block, and down the side driver side frame rail.
 
1-ton said:
One thing you might want to look for is that the wiring harness, running down the driver side frame rail, is not rubbing against the frame rail and grounding out. Thus causing all kinds of fault codes to trigger.

GM trucks in your trucks year range where known for this. I had two of them with this problem. I cured the problem by just throwing some new wire shielding on the wire loom running from the firewall junction block, and down the side driver side frame rail.
Click to expand...

I think its okay, I was just under it running a wire for my trailer brake controller and put it in that harness loom.
 
I'm looking at the troubleshooting procedures for code 13 and it shows a purple wire for the o2 sensor and a tan wire for an o2 ground to the engine. Does anyone know where this wire grounds? Is it on the intake somewhere? Is this ground only for the o2 or is it a common ground for the ecm?
 
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According to my *91* R/V wiring diagram, the tan wire (O2 low/ground) is a separate wire all the way to the ring terminal. Fuel pump relay ground and ECM ground are also terminated at this ring terminal however, so it's not really separate. If the ring terminal wasn't hooked up or the terminal corroded then you'd have problems with those as well.
 
dyeager535 said:
According to my *91* R/V wiring diagram, the tan wire (O2 low/ground) is a separate wire all the way to the ring terminal. Fuel pump relay ground and ECM ground are also terminated at this ring terminal however, so it's not really separate. If the ring terminal wasn't hooked up or the terminal corroded then you'd have problems with those as well.
Click to expand...

Is that the one that is on the intake manifold?
 
Dunno where they put it on TBI, but my guess would be somewhere on the passenger side rear of the motor, intake or back of head.
 
I went through the troubleshooting procedure for code 13 and I'm not sure what to conclude from the results. with my meter on the 2 terminals at the ecm and with the engine around 2000rpms the reading steadily increases, the ses light came on when the reading was I think .58v it then proceeded to steadily increase to 1.4v before I stopped testing. I then unplugged the o2 and and jumpered the o2 plug to ground and the reading was .39 at the ecm with the engine running. I then removed the jumper and checked the voltage at the o2 plug with the key on and engine not running and it was 1.4 volts. So the chart says "open ckt413 or faulty connection or faulty ecm" I will try cleaning the connections at the ecm, i doubt the ecm is faulty since I've had this problem with 2 different ecms. I've checked continuity on the o2 wire and it is good. I'm not real sure what to look for now? I've got to take a trip in the Jimmy in a week and I hope I can get this fixed so I can pass up a few gas stations instead of filling up at every one. I'm almost to the point of cutting the o2 wire at the ecm and running a new wire to the o2 sensor. I guess I could always solder it back together. I'll wait for input before I start sniping.
 
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