trans9_5am

Tom,

I sent you an email

Fred,

Let me know sometime this week if you had a chance to look over the excel file i sent you

Brad,

I am unable to get a log while driving the car right now because i do not have datamaster on my laptop. The only thing i have on there now is pcm comm and i dont believe the Serms are shown on there but ill check the next time i fire it up.

elisowski

Seems a though I've found several things that cause a one-sided BLM problem.

I just changed my MAF becase it was going bad and causing both banks to show a false lean. A bad MAF affects both sides of the motor, not just one. An air leak between the MAF and the manifold will cause both sides to run lean. A bad EGR valve will affect both sides as well. I had an exhaust leak where the EGR pipe met the header and caused the same thing. While your at it, check to see if the EGR pipe has a hole in it.

A burnt plug wire, bad plug, exhaust leak, wire loose at the opti or a bad O2 will affect one side of the motor. Even an exhaust leak at the Y-pipe or header connection will suck air and cause lean readings. A vacuum leak that is attached to the right side of the manifold will affect the right side also. I have an LT4 intake so I'm not sure what you have on the right side.

Check the CCP (charcaol canister purge) vacuum line and especially the EGR solenoid vacuum line (although I think it's on the left side) and the line that connects to the to the right side valve cover, although that may attach to the TB on an LT1.

Check everything on the right side. It's very frustrating but you will eventually find it. It took me about two months off and on and replacing every hose, plug and wire until I found it.

Good Luck, persistence pays off.

Ed

trans9_5am

Ed,

Thanks for the awesome reply. I am going to check everything you told me to. I deleted my EGR and made my own block off plates. I am going to start here and go down your list to check for problems. Maybe somehow air is getting sucked in through the plates i made but i guess i wont know until i check them. I think i am going to take off the EGR plate and gastket as well as the header gaskets and put some kind of silicone on the gaskets to help keep them from sucking any air in. Does anyone know a good silicone or form-a-gasket to use around these gaskets. I figure just a little on each side of the gasket will work.

I used non-hardening form-a-gasket on my slp shorties and never had a problem. Can anyone recommend anything good to use or tell me if this is a bad idea? Thanks

Brandon

[edit] The left BLM's are higher than normal too. They are running at 142 while the right side is pegged at 160.

trans9_5am

I have an update on some findings with my split BLM issue. The left bank is running at 148 and the right is maxed out at 160 in open loop. I took out all eight plugs and got a pic for you. Plugs 6 and 8 were very distinct from the others. The porcelin on both was dark brown or a blackish color where the other plugs were mostly white. I took a few pics but they are not very good. Also #7 was dark on the end of the plug like 6 and 8 but not as bad. I am not sure but maybe air is being sucked in from the back side of the intake somwhere, possible closer to the passenger side of the car. Here are some pics for you to look at:

http://community.webshots.com/photo/...88409073zDJnwY

http://community.webshots.com/photo/...88409397EiIdcz

The very tips on each plug were like a whitish or tanish color so i think they might be burning OK. If anyone has a website with pics of spark plug diagnosis i would appreciate that. Someone PLEASE try and help me with this. I dont want to drive the car any longer with this problem.

Brandon

turbo_Z

Did you fix that malfunctioning O2 sensor problem yet? There are 4 wires in the harness going to the O2 sensor. I am not 100% sure what the colors are but if they are the same as that of the O2 sensor itself then there is a black, purple and 2 brown wires.. maybe you got the 2 brown ones swapped around wrong???

Injuneer

Maybe its just my monitor, but the photos are so blurry they are useless. It does sort of appear to have a VERY white porcelain tip on 5 of them, and light tan on the other 3, which does not support your position that it is running rich.

My memory is fading, but didn't I send you a number of comments on your log when I first reviewed it? Have you followed up on those? Appears the BLM's are high because it needs extra fuel added.

ZMAN Z28

If you don't have a cat, you car will smell very rich no matter what you do. I don't know if you have yours removed or not.

Z

trans9_5am

To help clear up alot of things i will get another datalog for you guys and send it to you.

Turbo, yes i fixed all the wires but still no change. None of them are crossed and all are functioning just as they were from the factory now.

Injuneer, i know the pics are blurry and i agree with you that 5 of the porcelain tips are white. I sent you comments to the questions you wrote but i never got a response. I will get another log for you since i have a better understanding now of how to record a USEFUL log with datamaster. It would probably make things alot more clear for you though if you see if you got my responses, maybe the email did not send correctly or something though.


Zman, I dont have cats but the smell is very strong. I dont know, maybe its normal.

Brandon

Injuneer

Let me post my comments and your responses, so everyone knows what the previous concerns are. That way, maybe they can respond as well, particularly with respect to the monoblade and the IAC problems.
=========
INJUNEER COMMENT:

The data log is probably one of the strangest ones I have ever seen. There are single data points that make no sense at all, stuck in the middle of "normal" readings.

-Record 621: The MAF GPS has been reading 30gps, and in this record it jumps to 286.9gps for no reason at all -Record 554: IAT is running at 16.3*C (61*F) for the entire run, but this record jumps to 112*C (234*F).

-Record 47: System voltage is mid-13V's for the entire log, but this one point shows 20.1V Similar glitches in the data log show injector pulse widths of 504mSec, duty cycle of 409%, left BLM at 208, etc.... there is either noise in the data link to the PCM, or the PCM is putting out some corrupt data. Have never seen anything like this in maybe 500 data logs that I have reviewed.

BRANDON RESPONSE:

Where to start. Well first off i believe the numbers that you are seeing that seem out of the norm are due to my datalog. When i was logging the information, for some reason DM kept telling me that i was losing my ALDL connection (which has never happened to me) so i tried to fix it and no change occurred. Like i said usually i have no probelms like this so i will get another scan and go from there.

INJUNEER FOLLOWUP:

Have you been able to eliminate the communications problem with DataMaster?
================================================

INJUNEER COMMENT:

For some reason you didn't log coolant temp. It helps to have that.

BRANDON RESPONSE:

I can add the coolant temp when i do the next scan.
What should i take out since i can only log 32 parameters?

INJUNEER FOLLOWUP:

Eliminate anything that has duplicate data columns, you don’t need both “TPS %” and “TPS Volts” for example, or "inlet air temp" and "inlet air volts". One of those can be deleted.
=============================================
INJUNEER COMMENT:

Appears you started it and let it idle at about 1,000rpm. Then after about 72 seconds you opened the throttle slightly and held it there for 24 seconds, and the RPM climbed to 1950rpm. Then you goosed the throttle and rev'd it to 5,400rpm. Is this a correct description of what you did?

You only ran the data log for about 111 seconds, and it never went into closed loop. Limits the usefulness of the data.

BRANDON RESPONSE:
I have never really sent anyone a DM log to look over so i didnt know the techical way to do it. How long should i let it idle? Should i give it some gas and keep it at a steady rpm for a certain lenght of time and if so what rpm and what lenght of time? Should i do a WOT log? Or would it be best to be driving the car around while scanning the car?

INJUNEER FOLLOWUP:

Start the car. Let it warm up. Do not touch the accel pedal… I need to see what the PCM is doing, not what your right foot is doing . Drive it for a couple minutes at low load/low rpm “normal” driving. Then do a complete pull from low rpm to redline in at least one gear.
==============================================

INJUNEER COMMENT:

When you just let it idle:

-MAP seems high.... about 68kPa. What cam are you running?

BRANDON RESPONSE:

I have a built 355 and my cam is a decent size for a 355. I am running
a custom grind 236/242 .608/.576
111 from CMS with my stage II heads from them as well.

INJUNEER FOLLOWUP:

It’s going to be hard to get it to idle well with all that overlap.
=====================================
INJUNEER COMMENT:

-MAF gps looks high at 15.5, but that goes somewhat with the high idle. You have a target idle speed of 1,000rpm. Why so high? Who did the tune?

BRANDON RESPONSE:

Brayan @ pcmforless

INJUNEER FOLLOWUP:

Have you discussed any of this with him?
===================================

INJUNEER COMMENT:

-IAC motor is wide open to maintain the idle speed. If idle speed drops, IAC can't open any more to control the idle.

BRANDON RESPONSE:

Does this have anything to do with the AS&M monoblade i am running? I Have heard they catch hell with the IAC and are hard to get right???

INJUNEER FOLLOWUP:

I have no experience with the monoblade. Doesn’t that require that you completely cut away the IAC hole on the intake manifold, between the bores? That’s going to screw up the IAC system, and possibly contribute to split BLM’s, but I have no experience with one.
===========================

INJUNEER COMMENTS/NO RESPONSE:

-TPS volts, IAT, system volts look OK.

-BLM's are "split", and adding fuel. 142-left, 160-right. O2's show the left side is still running very rich, and the right side is running very lean.

When you open the throttle up slightly, and rpm increases:

-Left side continues to run rich, at least that's what the O2's show.

-Right side starts out OK, but then the right O2 mV's drop to extremely lean condition, and it just stays there. Almost like something is not flowing fuel to the right side. Or the O2 sensor is messed up. Or the O2 sensor is exposed to air, and not exhaust.

The right O2 stays lean for the rest of the log.

Something is messed up.... the data stream is being corrupted, with the weird readings that don't appear to affect anything else. Maybe DataMaster is having problems reading the PCM???

There is a big imbalance in the fuel between the left and right side of the engine. Either the injectors aren't delivering the fuel, or the O2 sensor is wrong.

The engine is not getting enough air to idle correctly. The IAC counts are way too high. Maybe open the throttle blades slightly with the stop screw. Just make sure the TPS voltage doesn't go over 0.90V

MAP seems too high, but I don't know what cam you are running.

BRANDON GENERAL RESPONSE:

Ok here is one the concerns i have with my car. When i pulled the engine out from the bottom of the car and was putting it all back together, i rerouted a set of wires (like 7 or 8) behind the pass side header (along the tranny) to keep away from the heat of the headers.
When i got the whole engine back in and everything back in place, i was hooking up my last set of wires for the pcm, and the ones that go inside the car and noticed they they would not reach because they were attached to the ones that i routed along the tranny close to the firewall. So i was so frustrated at that point that i just cut all of those wires and spliced them back together later.

I am not exactly sure which wires they were but i know the knock sensor was in there, a wire or two that went to the starter, a big purple wire, a small ground wire that grounds to the block, and the wires that go to my right O2 sensor. I can take a pic of them and send them to you if you want. For some reason i have a bad feeling about these wires. I feel as if i screwed up when i did this but i dont know how to fix it. How should i go about doing this. Right now i just spliced some "extensions" in there with butt connectors. Atleast if i get this fixed i can eliminate this as a problem.

I also am going to check my EGR block-off plates. I made them myself and they may be sucking in some air.
I want to take them off and apply some silicon to the gaskets to help prevent this problem. What would you recommend? I have used a non-hardening form-a-gasket before and had good experience with it.
=============================

I guess your responses sort of left me in the cold. You’ve made some major changes to the engine, with things like Monoblade, a fairly large cam, and you’ve hacked some of the wiring. This isn’t your average engine, and its got a lot of problems I’m not familiar with… I’ve never seen a log from an engine with a monoblade.

Just MHO…. You are expecting a lot if hoping to solve all this over the internet. The car needs “hands-on” attention. I can look at data logs, but I can’t get the feely-touchies by actually listening to the car run. So I backed off.

If you want to send another log, I’ll look at it. You will need to be patient, since there are a few people ahead of you, and as you can see, I’ve already put a ton of work looking into the first log you sent.

Fred

lillbush5555

I am having the SAME problem here. My thing is the 02 on the left isnt reading and is stuck between 30-40. The RBL is pegged at 160 while the left ones moves normal. The R 02 is reading and the left isnt. I thought it was the 02s but it isnt seeing as how I replaced them both. If I swutch the 02's the problem is still there doesnt matter which 02 is on which side. I checked the harness and everything is fine. I have gone over this car with a fine comb and came up empty. It seems to flood the motor with gas while cruisng and the car starts to buck and back fire under steady gas. at WOT it runs like a bat outa hell. as soon as someone has an answer please let me know as this car is pissing me off. BTW it is a
383 stroker with lingenfelter CNC's heads and intake, custom cam, vortec s trim, 50 LB injectors, LT, true duals, OBD1 conversion

Thanks
Matt

ZMAN Z28

Just as a comparison, when my car was running, I would smell like rich exhaust after I exited my car. Sorry I can't help on your BLM issue.

Z

turbo_Z

Sounds like the common BLM split there. Problem with running larger injectors as I can see is that at their smallest increment of fuel at idle it will dump in too much fuel. They just cant spray on small demand as well as say 30#... so that may be exaggerating the issue some. However a blower cam Id think wouldnt have as much overlap which is what causes the problem in the first place.. maybe you can give up some specs like duration and lsa on that cam to help figure out what else might be creating the split. I can setup a .bin file so it wont add fuel at idle and wont split but only if its a last resort.

lillbush5555

The cam is 224/236 .502/.520 on a 114 LSA. I am running 1.6 RR so the lift is going to be a little more. I also forgot to say I have a BBK 52 MM TB. I dont belive I had this problem until I put that on. also with that TB it is sticking at idle so my car idles at 1500 sometimes. If you pop the hood and close the throttlebody back up the idle drops and the car runs fine. Except for the split BLMs. I know there is a write up on the TB but I had no luck in my search lastnight. so if that is infact the problem can someone post the link to the writeup with pictures.

Thanks
Matt

Thanks
Matt

ZMAN Z28

"The cam is 224/236 .502/.520 "

That is .535/.555 with 1.6 rockers. I ordered the same cam but on a 112 lobe sep.

Z

trans9_5am

Fred,

The reason i have not been able to respond to your comments yet is, that SAME DAY that you wrote this, something happened in to the bottom end and i have not been able to drive the car since. I think you guys are right though, the car seems to be running way lean. It seems like i need to up the pressure with an afpr because it almost seems like the plugs that are furthest from the pressure regulator are running the leanest. #5, 7, and 8 seem to be getting the most fuel and these are the ones closest to the fpr. Dont know if this is the cause but it seems like a logical thought. Thanks for all the help and as soon as i get it up and running again, i will get some logs and if you have time to look over them that would be great.

Brandon