Jirka Pospi

Hi All

Thank you for this tools. I have 95er Z28 and since I bought my camaro (6 years ago) I am still facing problem running rich. i changed spark and cables, check fuel presure, temp senzor etc. Could someone help me to check logs what could be wrong? it is quite difficul to find in my country someone who is expert on LT1 angines.

BR George



https://drive.google.com/file/d/0Bzd...it?usp=sharing

GaryDoug

Hi George,

I suggest you start a new topic in this area: https://www.camaroz28.com/forums/gen...-body-tech-46/

You probably won't get much response in this location since it is not about general performance troubleshooting.

Also, what version Scan9495 are you using? The data format has been changed in the newer versions and the file you posted has a lot of file errors. I suggest you download the newest program version.

Injuneer

Welcome to CamaroZ28.com. Not many members here from the Czech Republic.

I downloaded the file, and as Gary points out, there are numerous problems with the data not indexing into the correct columns, and jumping all over. You need to follow his advice and download the latest version of the software.

I think I identified the fuel trim cell #, and the left and right long term fuel trim (LTFT) columns (and movements to different columns). Appears you were idling the engine, in Cell #16, and the left side long term is bottomed out at 108 (PCM is pulling out the maximum allowed 15% of the normal fuel requirement) and the right side is at 110, meaning it is close to the maximum allowable fuel subtraction.

The PCM is reading the A/F ratio as rich, and is subtracting fuel to lean it out. Hard to tell if there is anything in the data log that would point to what is causing the problem, because of the incorrectly indexed column entries.

I will copy your post, Gary's post and my post to a new thread on the "LT1 Based Engine Tech" forum. Click this link to find the new thread:

https://www.camaroz28.com/forums/lt1...uested-878849/

Jirka Pospi

I see that also i ccant open that file strange is taht im using lates 1.0.8 version :/ mybe is necesary to set regional and language format seting to us? i will try later. Thanx both of you for possible help

EDIT: when i have region seting in windows to Czech even i received error during opening your test log file. after switch to US it is ok i will create new scan log when i will drive from work

Jirka Pospi

Hi all so here should be functional log https://drive.google.com/file/d/0Bzd...it?usp=sharing

Thanks for any idea or tips in advance

GaryDoug

Sorry for the late reply but I didn't get a notification for your post, probably because it was moved.

I notice that the SES lamp may be removed or burnt out because you are getting a DTC 11 indicating a problem with the lamp circuit. I also see that the fans are running almost all the time, perhaps because of that DTC. Your BLM's are slowly creeping down during the session while the temp is climbing naturally. Perhaps Fred can provide some insight.

Injuneer

It's running very rich, and the BLM's are bottoming out, or close to bottoming out in the fully developed cells. The flag indicates there was a reset during this period. That's not a good idea. It takes all the BLM's back to 128, and the cells that you don't drive in very much do not have time to fully develop and stabilize. As a result, they may be close to 128, simply because the engine hasn't operated under the required RPM and MAP conditions a sufficient amount of time. But as Gary notes, BLM's are dropping.

#5 - 108/112; #16 - 110/111; #17 - 108/112; #18 - 110/109

17 and 18 are mathematically calculated values, that allow the PCM to control the A/F when it is not in closed loop, and when it is operating in conditions that default to these cells for accel (18) and decel (17). But they indicate there is a problem.

Since the PCM is using the BLM's to subtract fuel, when it goes into power enrichment mode (~full throttle), the BLM's will default to 128. When that happens, the O2 sensor readings indicate a rich condition (950+mV). Recognizing that the narrow-band sensors are not very accurate once you get away from 14.7:1, they can't be taken as absolute values, but they are higher than normal. The fact it runs rich in PE mode with 128 BLM's would tend to confirm that the engine is operating in a true rich condition, and not a false rich condition.

The MAF AFGS is around 7 gram/sec at idle, and 230-ish at 5,000+ RPM/WOT, so that doesn't appear to be the source of the problem.

MAP looks a bit high at idle, at 41kPa. Could indicate misfires or incorrect valve adjustment. Is the cam stock?

Are the injectors stock? Have they ever been replaced? Do you have a part number?

Jirka Pospi

Hi

Thanks both for feadback. That MIL error code will try to solve by guide this week. It could be only the bulb becouse if i want the strat up it does not light.... but it also could be falty PCM . I have car for 6 years and hard to say if anyone did some changes on it before. Think thet cam is stock but wander if timing chain could be bad. One thing i changed in PCM is gear ratio from 2:80 to 3:23 by hypertech programer. I have no idea how to check if injectors are 24LB but i know that fuel presure is ok and nothink is leaking (checked by fuel presure meter) Way is to lend it from impala SS LT1 engine from my friend or buy some on ebay. For your information for 10liters of fuel i drive around 20+ miles i

If you can rekognice type by picture here it is