Lean Start issue

Jim · Post by **Jim** » Tue Apr 18, 2006 2:28 pm

........

Jim · Post by **Jim** » Tue Apr 18, 2006 2:30 pm

You don't KNOW wether the engine is Lean or Rich , yet .

Anybody can make a guess as to what's happening ,
coming up with an exact correct answer is something else .

Could be:
wacky VE table
wacky Advance Table
wacky AE settings
heat soaked IAT Sensor
scratchy TPS Sensor
and at least 5 or 6 other things .

If I was there , driving the car ,
I might be able to make a more educated guess .

A WB 02 with a cheapo LED Meter on the dash would tell you instantly ,
(actually with about a 250ms delay)
that it is or is not too rich or to lean .

Until absolutely all tuning tricks have been thoroughly gone through ,
10 or 15 times each , this is not a MS problem , it is a tuning problem .

You've heard the old Chinese saying
"One Picture is worth a thousand words" , well
"One WB 02 is worth at least a Million words"

Have you tried increasing your idle speed yet ?

Have you still got that WB 02 sitting on the seat ?!?!

There is no "Easy Button" answer .

...................Jim

rs2000 · Post by **rs2000** » Tue Apr 18, 2006 6:18 pm

I've had a look at your logs.. I don't think that o2 sensor is working, it doesn't change enough and it never goes above 0.5V. That was the NB right? It appears not to be heatsoak, you do get a 10 degree f increace in intake temps but this very quickly drops after the restart.

A few more questions, Was ms on and logging while the engine was turned off? If it was then your coolant temp drops very fastin the 1st log at 1024.041, which isn't right. Is it possible to check that o2 sensor is reading right? Really without this being confirmed as correct (and i don't think it is) theres not alot we can do..

Your pulswidths after the restart are a lot higher so your afterstart enrichment must be kicking in, but the o2 reading doesn't budge.

And just to confirm it is running wrong for about 1 min?

Your msq look ok.. Your VE table looks wacky, but i think thats because i'm not used to seeing big injectors on 4cyl turbos..

turbosl2 · Post by **turbosl2** » Tue Apr 18, 2006 9:45 pm

rs2000 wrote:I've had a look at your logs.. I don't think that o2 sensor is working, it doesn't change enough and it never goes above 0.5V. That was the NB right? It appears not to be heatsoak, you do get a 10 degree f increace in intake temps but this very quickly drops after the restart.

A few more questions, Was ms on and logging while the engine was turned off? If it was then your coolant temp drops very fastin the 1st log at 1024.041, which isn't right. Is it possible to check that o2 sensor is reading right? Really without this being confirmed as correct (and i don't think it is) theres not alot we can do..

Your pulswidths after the restart are a lot higher so your afterstart enrichment must be kicking in, but the o2 reading doesn't budge.

And just to confirm it is running wrong for about 1 min?

Your msq look ok.. Your VE table looks wacky, but i think thats because i'm not used to seeing big injectors on 4cyl turbos..

I had to remove some of the datalog to condesnse it into 2 files to try to upload it to MSEFI, which wouldnt let me in the end. I think for some of the time i had the 02 off to tune. I turn the ego off and tune the car, then turn it back on when finished. I think the 02 sensor doesnt have anything to do with it because it does the same with it on or off. As for the AE could this value being to high cause me to have a really lean issue, i would think not but someone stated above that it could. Now what i will do is, get rid of these 2 files, and load the 1 orignal one http://serv01.siteground118.com/~albany ... ronics.xls so now you can view the original datalog untouched.

Looking at it again, could it be when i turned the car off and let it sit for a few mins? Why the temp droped

turbosl2 · Post by **turbosl2** » Tue Apr 18, 2006 10:02 pm

Jim wrote:You don't KNOW wether the engine is Lean or Rich , yet .

...................Jim

I def know that the car is lean, 100% sure, my WB02 says so even after i wait for 30secs, still lean, pops through intake, car stalls if i try to give it gas, i know that it has no fuel, the engine sounds totaly diff if its rich, and on startup the WB02 would say rich, sometimes it will be okay and run great and be were it should, others it will be extremly lean, it will run, but BARELY. I agree its a tuning problem, its very hard to find what i am doing wrong

Jim · Post by **Jim** » Tue Apr 18, 2006 11:12 pm

Are you using MAP based AE ?

turbosl2 · Post by **turbosl2** » Tue Apr 18, 2006 11:45 pm

Jim wrote:Are you using MAP based AE ?

not that i know of. I dont really understand what you mean. for my AE its just one scaler in the warmup wizard, i am not using a table if thats what your asking.

rs2000 · Post by **rs2000** » Wed Apr 19, 2006 7:59 pm

turbosl2 wrote: I think for some of the time i had the 02 off to tune. I turn the ego off and tune the car, then turn it back on when finished. I think the 02 sensor doesnt have anything to do with it because it does the same with it on or off.

Yeah i know you have ego correction off, however the 02 voltage should still read correct and be logged in megatune. Watching the o2 is the only way to see what is actually happening.. yours doen't appear to work how i would expect, which means looking at logs can't really help the lean start as i can't tell where the lean condition starts or finishes. From what i see the engine runs lean (under 0.5v) for the entirity of both the logs you posted.

turbosl2 · Post by **turbosl2** » Wed Apr 19, 2006 9:08 pm

rs2000 wrote:
turbosl2 wrote: I think for some of the time i had the 02 off to tune. I turn the ego off and tune the car, then turn it back on when finished. I think the 02 sensor doesnt have anything to do with it because it does the same with it on or off.
Yeah i know you have ego correction off, however the 02 voltage should still read correct and be logged in megatune. Watching the o2 is the only way to see what is actually happening.. yours doen't appear to work how i would expect, which means looking at logs can't really help the lean start as i can't tell where the lean condition starts or finishes. From what i see the engine runs lean (under 0.5v) for the entirity of both the logs you posted.

I see, do you have any idea on what might be going on? Could it be a bad 02 sensor, i have a connector where i can hookup my WB02 but i would not be able to until about 3 weeks. Should i decrease my AE lower then 35% that its set at. Also do my injector characteristics look correct, it seems i had to set the ms/v correction to around .12, sometimes when i would turn an accessory on when idleing my car would go extremly lean or even stall cause its so lean.
Thanks for all the help so far