My car seems to have power, starts up fine, idles fine for about 1 minute and shuts off fine but if I idle in "Drive" for more than the length of a red light, it throws a check engine light and dies. It dies at almost every red light now with SUCKS.

I just took a few scans and if you can see if anything is wrong I'd appreciate it.

Started with cold startup and you can see the time Progress as the car idles:






Turned the car off.

Started it back up, let idle for 1 minute:



Took it for a short drive and let get into closed loop:



Thanks

 

When the SES light comes on, what codes are set? I'll bet you get DTC 44 and DTC 64.

Why not use the "logging" capability and post the log on a free FTP site, so that it can be reviewed more easilly, and in depth.

Your O2's are reading extremely lean, and its pouring fuel into the engine. The 160 BLM's are adding 25% extra fuel over what the PCM thought it should be using. The 194 INT's (not sure why your scan labels it "O2 sel") are adding 50% more fuel on top of that. In effect, your PCM is supplyingalmost twice as much fuel as it would normally calculate.

Does it appear to be running rich - actually reaking of unburned fuel? That would definitely cause it to die. And it should be setting codes for lean readings on both O2 sensors. If its running that rich, there's something wrong with the O2 sensors. They should not hang at numbers of 100mV and below.

Also appears to heat up the coolant very slowly. Either that, or the constant low readings from the O2 sensors is causing it to take a long time to go into closed loop. You shouldn't have to drive it to make that happen.

If its a "false lean" condition that causing the excess fueling, do not run it any more than you have to. The excess fuel will wash the lubrication off the cylinder walls, destroying the rings, then dilute the oil to the point where you start hammering bearings.

If its a "true lean", you need to look for a huge vacuum leak, extremely high fuel pressure, incorrect valve adjustment, or screwed up tune. Who tuned it? Do you still have stock injectors? The MAP looks a bit high, possibly indicating problems with the valve adjustment or the tune.

 

Should I log the car while driving it or idling?

Yes I smell unburnt fuel

I personally believe it's the 02 sensors. I'll check for a vaccum leak, but wouldn't that cause a really high idle? The tune was done by pcm4less. The valve were set about 10k miles ago and have locking screws and this is fairly recent problem.

The engine sounds perfect for about a minute and then it just chokes on itself, shakes hard and dies.

Thank you for your help, I will change the 02's and add fresh oil and go from there.

 

btw this will be the second set of bosch 02 sensors I've gone through in 1 year.

 

Try to notice if it dies when it goes into closed loop... this would be a sure sign of bad 02's since they are reading very lean would make the computer add alot of fuel.

AFter that, try simply unplugging your 02's, this will make it stay in open loop. If it continues to run great in open loop then thats' one more reason to blame the 02's.

 

The car doesn't start dying until it warms up. I'm looking at buying Denso brand o2's right now.

 

Why don't you just buy the OEM AC/Delco (now Delphi) O2 sensors that your engine was designed to use? Many people have had problems with brands other than AC/Delco.

 

the Denso are $70 for 2, the ACDelco are $144.00 for 2

 

I would definitely try the Delphi or AC-Delcos.

 

With the money I wasted on 2 sets of bosch I think I will spend the extra cash for a set of AC-Delco.

 

Yes, it's hard to tell from the snapshot in time, but it appears that the O2's are reading extrememly lean. Your BLMs are maxed out as well. Another indicator of the O2's thinking it's running lean.

Dan

 

OK.... you save $74, you replace them every 6 months, and your engine doesn't run right.

What's wrong with this picture?

Did you try the online source for GM parts, linked on Shoebox's site?

http://shbox.com/1/4th_gen_tech2.html#Dal_and_Jason

 

"If its a "false lean" condition that causing the excess fueling, do not run it any more than you have to. The excess fuel will wash the lubrication off the cylinder walls, destroying the rings, then dilute the oil to the point where you start hammering bearings."

I stopped driving the car after I read this post and I just finished replacing my 02's. I just checked the oil to and you were right. I actually saw clean fuel drain out of my oil pan for maybe a half second. some of the oil looked milky. I could definately tell it was gasoline. Hopefully these new 02's will solve my problems.

 

......

 

Alright new o2's are in, fresh oil is in and the car is still running like junk.

Here is a log that I saved: http://www.lt1engine.com/temp/logcomm.txt

Here are 3 more screen shots:

http://www.lt1engine.com/temp/7.gif
http://www.lt1engine.com/temp/8.gif
http://www.lt1engine.com/temp/9.gif