Cascade Crew

Twilightoptics · Posted: Wed Oct 05, 2011 6:08 pm Post subject:

Cant see the log, but 108 blm is peg rich fuel trim

Alphius · Posted: Wed Oct 05, 2011 6:33 pm Post subject:

Yep, what he said, 108 is pegged rich and your O2 voltage is still in the .900s, which means your O2 is reading full rich as well.

Any way you can send the datalog to one of us?

popballz · Posted: Wed Oct 05, 2011 8:58 pm Post subject:

popballz · Posted: Wed Oct 05, 2011 9:43 pm Post subject:

manual says that tps volt should be over .5 and it is 0.41 for most of the time even when i was accelerating.. sound like a bad sensor?

Alphius · Posted: Wed Oct 05, 2011 10:24 pm Post subject:

BLM means "Block Learn Multiplier". It is the long-term fuel trim for the ECU. When it is at 128, the ECU has not adjusted the fuel trim at all from it's base table settings. This is a good thing. The lower that number goes, the more fuel the ECU is trying to remove due to O2 sensor feedback. It bottoms completely out at 108.

I have an email link below my posts, just use that to shoot me the datalog and I'll take a look. It's hard to say what could be going wrong from your "point-in-time" screenshot.

EDIT: Check this for a BLM/INT description that is pretty spot on. Smile

http://www.gnttype.org/techarea/faq/BLMINT.html

Twilightoptics · Posted: Thu Oct 06, 2011 12:34 am Post subject:

TPS should be set at roughly .5 throttle closed... then increase linearly as you open the throttle to reach IIRC 4.0 roughly at WOT.

If it stays at .5 the whole time of driving, your TPS is indead dead, and the ECM has no idea how far open the throttle is.

popballz · Posted: Thu Oct 06, 2011 12:43 am Post subject:

its weird that voltage doesn't change much, i just tested i a few months ago and it seamed to work fine with the volt meter. i'll replace it and see what happens

Twilightoptics · Posted: Thu Oct 06, 2011 1:01 am Post subject:

Check again with a scan tool or your volt meter before replacing. It could be a quirk in the log.

Alphius · Posted: Thu Oct 06, 2011 10:52 am Post subject:

OK, the TPS is responding completely normally, although you do have a Code 22 stored which means "TPS V Low" because at idle you're below .5 volts. So the TPS needs adjusting. There is no full throttle on this datalog so I can't tell you if the high voltage is incorrect.

You also are storing Code 33, which is "MAF High". I am not sure about this as the MAF voltage is not expressed in the datalog, rather airflow is and the numbers look OK. Could be an old code since you say you replaced the MAF?

You are also storing Code 45 which is "02 Rich" as we already know.

I do not believe that any of these codes are the problem. Regardless, I would adjust your TPS and clear the codes out and see if any of them return. We would expect the 45 to return because none of your codes make me think a sensor is bad.

Given the information you've provided, I would guess your injector wiring or injectors are at fault. If it's possible to do, when it's running badly unplug one injector at a time and see if it smooths out and runs better with a certain one unplugged.

If your wiring is messed up and grounding out, it is possible (and likely) that you will have 4 injectors at a time misbehaving since the TPI is a batch-fire system. The way you could test this is to probe resistance between the two wires to each injector and a ground potential. You should have infinite resistance to ground on every wire in every injector plug with the car off. While you're at it, probe resistance between the two pins on every injector and post those values up here as well.

aaron_sK · Posted: Thu Oct 06, 2011 10:59 am Post subject:

Gabe, is the O2 sluggish? Could just be a crap sensor. I was getting about 500 miles out of the garbage Bosch single-wire units.

Alphius · Posted: Thu Oct 06, 2011 11:05 am Post subject:

aaron_sK · Posted: Thu Oct 06, 2011 11:12 am Post subject:

Alphius · Posted: Thu Oct 06, 2011 11:19 am Post subject:

aaron_sK · Posted: Thu Oct 06, 2011 11:25 am Post subject:

Alphius · Posted: Thu Oct 06, 2011 11:30 am Post subject:

Makes sense now. I pulled the page with that info up so I see it now.

So his code 33 must have been set first, then code 22 later on.

TPS idles at .41V and full throttle looks like 3.90V

At least I assume that when he went from 10-83mph in 7-8 seconds that was full throttle. Razz

Regardless, the datalog shows both the TPS and MAF as responding normally so I would expect neither of them to come back if he resets his ECU. But 45 will return as soon as the O2 pegs out for a sufficient period of time.

aaron_sK · Posted: Thu Oct 06, 2011 11:37 am Post subject:

http://www.gnttype.org/maint/malf.html

It's a very handy chart, but based off of the turbo bricks, not F-bodies.

TPS is adjusted too low, but if it increases and decreases smoothly then that should be an easy fix.

GM stuff is weird about the O2 codes. I have watched a known bad O2 sensor in Tunerpro that never got below 450mv in any type of driving, but it would not hold high enough for long enough to throw code 45.

Alphius · Posted: Thu Oct 06, 2011 11:45 am Post subject:

I found that error code page too by searching on your text. Razz

O2 when running well cycles between .04V and .888V very regularly.

When it runs bad, the O2 goes to 1.04V while driving and sticks there, then drops to .94V or so at idle, with very little fluctuation.

That page says 45 can't set if there is a MAF error present, so the stored MAF code must be historical data, not a currently occuring condition.

aaron_sK · Posted: Thu Oct 06, 2011 11:57 am Post subject:

1 & 4: His underhood wiring was very messy the last time I saw the car. I do not think we can rule these issues out. It is also possible that it's running on seven thus causing the O2 to see lean.

5. Purge solenoid can get stuck. There is no feedback from it to the ECM so you are only seeing what is commanded, not what is happening. I highly doubt that this is the issue, however.

popballz · Posted: Thu Oct 06, 2011 12:43 pm Post subject:

sorry for the confusion but those first 2 codes were just me unplugging sensors to see how it idled. code 45 is the only one that comes back i just haven't reset them recently.

my wiring is all stock. the only wires that i have seen molested were the blinker wires. i will do an ohm test on the injectors probably tonight.

as i had my computer hooked up i moved the tps sensor by itself and the voltage stayed the same. although it did try to increase engine speed.

that is the second new o2 sensor i installed and it never even ran good for a day after installing. i would assume it is reading correctly. i read on TGO about this guy's o2 sensor grounding out within the ecm, it was a constant 1.4mv or w/e voltage term is used

it goes though these stages completely random, and usually a few times per 30 minute drive. it could very easily be a wire grounding or something but it would have to be a pretty loose wire that was jumping around alot.

lol it was wet out so i couldn't do a real "full throttle" so i used my method and just slid sideways a bit Wink

hey i will look into #5 on your list. i have read about those two items going bad. i JUST passed emissions with this setup a few days ago. this was my last required emissions test so i would be fully content with removing the charcoal canister if needed. i have yet to make a full datalog from cold to hot that is long enough. i'll try datalogging tomorrow morning to get a better and longer log

my next tests are to check ohms on the injectors and each wire to ground. and i should take a look at the canister and egr

thanks for all your effort guys!

Alphius · Posted: Thu Oct 06, 2011 1:45 pm Post subject: