ECM 1227165 6E mask
TunerPro shows:
No flags
= Air Word Mode=
False---Burnoff Failure Check Complete
No-----Skip Burnoff if >17 volts at start
No-----Burnoff Air Meter

I've tested the circuit, relay turns on when I ground D12 of the ECM 32 pin connector (disconnected.)

Previously it wasn't going into closed loop and I didn't think it was the O2 since I don't use the car as a daily driver.

So I changed the ECM then logged data at idle for 12 minutes.
It goes close loop in 3 minutes, idles around 900-1000rpm, the IAC starts at 160 counts and is down to zero in 16 seconds and remains zero, understandable given the high idle.
knock counts to 64 in 40 sec, knock count starts again when it goes into closed loop for another 3 minutes and stays at 142 for the rest of the run.
Before the new ECM knock counts were never more than 10, but it never went into closed loop.

Freeway run
It begins to jerk at part throttle (above 50mph,) or if I try to hold a speed, but not at WOT (if it does I can't feel it.)
Once I t get back and scan it there's a code 33.
I think the DTC 33 is cause by the burnoff not cleaning the wire.
Should I be concerned about the knock counts?

I'll log a run as soon as I can get another battey for my Laptop.

 

This is what the book has about code 33
Code 33- This indicates a faulty maf or map sensor, depending on your tpi system. MAF: This code is set when the ecm sees a indicated airflow of greater than 45 grams per sec (gps) and the tps is less than idle, and engine rpm's is around 2000. This can be set by intermittent problems, usually a bad connection. These can be extremely difficult to find. Check the harness and connections very thoroughly. Also check for routing of wiring near the spark plug wires, this can induce a voltage high enough to cause problems. If this code is being set along with other maf related codes (34 and 36) suspect strongly a bad maf connector. If all else checks out, the maf is bad. But since this sensor is very expensive, exhaust all your efforts to find and correct a wiring problem first. MAP: If you have speed density, this code will be set when the ecm sees the engine running, tps less than 2%, and a indicated air flow of 11psi or about 8" of vacuum. A faulty map sensor is the problem.

I had this code( and others) pop up and the car would jerk like your talking about and in general run like crap. The problem ended up being the TPS, check it out before you buy a new MAF. A TPS going bad can cause a code 33 because the MAF will be showing more air than the ECM thinks the engine can handle at any given throttle position.

Hope this helps.

 

The burnoff flag actually switches to "yes" when the ignition is turn off, I expected it at the beginning of the run cycle.
Things got worse, O2 sensor was going below 50mv and the ECM would drop out of Closed Loop and it idled real rough.
Turn out to be an intermittent MAF relay, but I had to reset the IAC before it would idle correctly, but the IAC is still at zero. I haven't driven it so the 33 could still be an issue. I'll update on that after I take for a test run.

Thanks all, for the help.

 

Code 36 is for the Burnoff not working and the Burnoff occurs after you shutoff the car to burn all the stuff you picked up on the sensing element while driving. It makes the sensing element red hot for a few seconds and then shuts it off.

DSmith hit it on the head with his analysis, if you are still having problems go back and read it closely. A TPS with a dead spot in it may cause a code 33.
Also if you break the tab off that is on the connector to secure it to the MAF, you may get an intermittent PIA problem.

All else fails before you slap down the cash for a new sensor, spray the inside of the MAF and the screens with Electronics Cleaner (TV Tuner cleaner) from the local parts store.

PS: Make sure you clear the codes before you do another test run.

 

Well, it's still ofter the first 5 minutes after it warms up and goes into closed loop.

What I really would like is if one of you who can data log in TunerProRT, or already has a file I can use to make some comparisons. (TIA)

Cleaning the MAF didn't help, I definitely going to replace it, but I need to understand what's going on.

 

If i were you, i would start off with the TPS.

My friend is having the same code 33 you are, and we at first thought it was the MAF sensor. We checked the relays and made sure the MAF is getting power correctly. Then we did a datalog with his MAF. We noticed that at part throttle it would have this tip in hesitation (or bog as i call it).

We swapped the MAF with a known good unit, from my yellow camaro and ran it again. It ran good for awhile until the code 33 came back up and we got the hesitation back.

As i was watching the datalog while he was driving, i noticed the TPS was jumping back and forth between two values while his feet was off the gas, at part throttle and it would bog. We suspect a TPS with a deadspot on it.

You can test the TPS a couple of ways. If you do not have access to a laptop or a scanner you can do it old school like i used to do.

Get a voltmeter and set it to check the Ohms. Then do a very slow, consistent sweep with the TPS lever from rest to the highest position it has. Do a search so you know which two leads to check. You can take the TPS off and unplug it to do this, or make jumper wires with three wires from the TPS to the connector. Poke holes or scratch some insulation off and get your voltmeter out.

If you have a deadspot, you will notice that the TPS has a very smooth transition increasing with a pattern and then it will jump to a higher value. You may have to do it a few times to pattern it out.

Now if you are checking all this and notice that your TPS is not adjusted at .54V key on, engine off (assuming you have an adjustable TPS), then you need to adjust it properly and try again.

You may also want to try posting on the Regional Board, there are a lot of Houston guys that are really cool.

I am posting an old datalog from my 86 Tuned Port, its not perfect by any means but it may give you a good idea on a stock tune.

 

I borrowed a MAF from a friend today, it idled better, and the 33 didn't flag even when it started to stumble again in the same amount of time.

"It ran good for awhile until the code 33 came back up and we got the hesitation back.
"
How much time is "for awhile"?
No code 33, but it's still stumbling.
Winzip says the file is empty. Pleas try again.
I'm suspecting the TPS, but would really like to see what a good TPS scan looks like.

 

He swapped the TPS and set it at .54V and also adjusted the timing a little. It runs much much better now. The code 33 has not reoccured and he reports that the car runs totally different with a nice transition instead of a low RPM stumble.

At idle we managed to get the the BLM's around 134 with just tweaking the injector flow constant and eyeballing the numbers.

Sorry about adding an empty .ZIP file, will post up with one with the Excel spreadsheet and the raw data.

 

Seems title is incorrect.
The burnoff wasn't the problem and it was working just not when I thought it should be.
The code 33:
I replace the O2 with a heated O2, somewhere I read that headers might require a heated o2. the code is still lurking around just not as often, or as predictable as before so, MAF my still need to be replaced.

What was causing the stumbling and lean popping was the EGR.
I had forgotten to connect the EGR valve, but there were no codes indicatating an EGR malfunction.
I set the MAT temp for EGR to 255 an no more stumble, or popping.

My many thanks to those who pointed me in the right direction.