Everyone with SD tune issue: VERY lean on starts after certain time delay.
03-31-2006, 02:08 PM
#62
Originally Posted by 98Z28CobraKiller
I would think that some of the tuning experts (HPTuners or EFI Live developers) have to have seen this before and if not, since sooo many people are having the problem, someone should be able to take them the car and show them.
We've asked the HPT guys about this, and they never had a good answer. They said they'd look into it, but never got back to us. I just keep posting in a bug thread over there to make sure it stays at the top of their list...but I know they have other fish they'd rather fry.
04-01-2006, 09:47 AM
#65
Originally Posted by Haans249
Make sure when you make changes, that you're changing one thing at a time. If you adjust your base spark tables, it'll throw off your AFR, if you add more desired airflow, it'll throw off your AFR. Pretty much everytime you make a change to your tune, it'll throw off the VE table and you'll have to recal it to get within .01 or 1% Try recalibrating your VE table and see if it helps. Log ONLY after you've come to a stead idle and are above 180* engine temps.
Lastly, look at all of your spark corrections that are based on ECT and IAT, you should zero out all of those tables.
I'm running OL SD and did have a similar problem, but it was correct and now my AFR is solid all the way through even on a cold start up. How did I correct this?
Adjusted Startup Airflow Friction Correction / multiplier / decay rates
Adjusted base spark at idle, made it the same as high/low octane
Zeroed out all spark correction tables that are based on ECT and IAT, including AIR and EGR tables.
Recal VE table at idle logging only values with ECT's about 180*
Best Regards,
Adrian
Lastly, look at all of your spark corrections that are based on ECT and IAT, you should zero out all of those tables.
I'm running OL SD and did have a similar problem, but it was correct and now my AFR is solid all the way through even on a cold start up. How did I correct this?
Adjusted Startup Airflow Friction Correction / multiplier / decay rates
Adjusted base spark at idle, made it the same as high/low octane
Zeroed out all spark correction tables that are based on ECT and IAT, including AIR and EGR tables.
Recal VE table at idle logging only values with ECT's about 180*
Best Regards,
Adrian
I have a question with regards to zeroing out the ECT and Iat base spark. I saw that on the IAT there really wasn't much correction so I wasn't all that hesitant to zero it out, I am concerned with the ECT base spark table though. It has some major corrections in the cold start idle operating range and I don't want to hurt anything. Could you please explain some logic on this to help me to justify this change?
04-01-2006, 07:49 PM
#68
04-01-2006, 08:01 PM
#69
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Originally Posted by jimmyblue
So can anyone tell me, whether this is a commanded lean
condition or a leaner-than-commanded one? I still haven't
seen (or else missed) that fundamental point answered.
condition or a leaner-than-commanded one? I still haven't
seen (or else missed) that fundamental point answered.
Leaner-than-commanded in my case.
04-01-2006, 10:52 PM
#70
Originally Posted by jimmyblue
So can anyone tell me, whether this is a commanded lean
condition or a leaner-than-commanded one? I still haven't
seen (or else missed) that fundamental point answered.
condition or a leaner-than-commanded one? I still haven't
seen (or else missed) that fundamental point answered.
http://www.hptuners.com/forum/showpo...&postcount=104
04-02-2006, 07:14 AM
#71
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Just eliminating the obvious... Have you verified proper operation from your WB? I run a WB on each bank, and noticed yesterday my left bank WB like to go thru the heater warmup cycle twice on every restart.
04-02-2006, 09:35 AM
#74
Originally Posted by TAQuickness
Just eliminating the obvious... Have you verified proper operation from your WB? I run a WB on each bank, and noticed yesterday my left bank WB like to go thru the heater warmup cycle twice on every restart.
04-02-2006, 11:09 AM
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Originally Posted by WS6FirebirdTA00
i dont get it on cold starts, it starts up nice and smoth then. if i richen it up to a 14.7 the surge goes away on a warm start. that is why i thought it was odd
if it's any consolation, i found, via bidi, my idle really likes 14:1 & about 36* spark for optimum startup's/MAP. I would have less extreme anamolies until i dialed this in.
04-02-2006, 01:28 PM
#78
Originally Posted by TAQuickness
safe to assume you are running a makeshift lean cruise?
if it's any consolation, i found, via bidi, my idle really likes 14:1 & about 36* spark for optimum startup's/MAP. I would have less extreme anamolies until i dialed this in.
if it's any consolation, i found, via bidi, my idle really likes 14:1 & about 36* spark for optimum startup's/MAP. I would have less extreme anamolies until i dialed this in.
04-02-2006, 11:33 PM
#79
Originally Posted by WS6FirebirdTA00
do not zero out the spark correction tables, those dont even have an issue wtih these start up conditions/problems
One these tables, I've seen upto and beyond a -8* change due to ECT temps. This does infact throw off your AFR, a lot, but it also maybe true that it doesn't affect the startup.
To answer Z's question, I zeroed them out to ensure that I would get a proper dialing of my VE without the computer messing with timing at lower temps. If you don't have any pinging problems with it zeroed, then you're fine and won't hurt anything. Also, my particular setup is VERY sensitive to spark changes, and zeroing out any changes to the spark other then whats commanded in the main tables and in the idle corrections would be a good idea for getting your base tune down. The less variables you have to worry about, the better. It also eleviates any possiblity of falling between coolant correction and no correction, which can cause swings in your spark timing, and idle stability issues.
Best Regards,
Adrian
04-02-2006, 11:53 PM
#80
Also, log all of your IAC valve airflows, startup, startup friction, follower, cracker, final airflow, desired, ect ect ect.... as g/s. Log your commanded spark, and watch your spark timings and make sure they're close to where they're commanded, and watch your IAC steps. Also, stop driving when you're logging your weird warm startup lean problem. Watch all your parameters and see if you can narrow it down to what suddenly changes after that 3 min period.
And just for pure ***** and giggles, I have my Catalytic Converter Light-off (B5901) and Cat Light-off Temp Multiplier (B5902) all zeroed (I have no cats), so give that a shot and see what she does. I'm thinking that you've got your VE table dialed in at idle with the +12 or so depending on the multiplier, spark corrections made by this table on a cold startup, and when you restart warm that +12 (or so) correction is not there which will also throw off your AFR pretty well. Adding more spark timing has the effect of leaning out, which makes hotter exhaust, which ties into the theory of Cat-Light-off causing the lean condition to light off the cats, and then it cuts out after 3 mins. That didn't make complete sense, but I think you've got the idea. I've only got 5 hours of sleep the whole weekend....my brain's a little mushed...freakin FTX's.
Just throwing some more ideas out there!
Best Regards,
Adrian
And just for pure ***** and giggles, I have my Catalytic Converter Light-off (B5901) and Cat Light-off Temp Multiplier (B5902) all zeroed (I have no cats), so give that a shot and see what she does. I'm thinking that you've got your VE table dialed in at idle with the +12 or so depending on the multiplier, spark corrections made by this table on a cold startup, and when you restart warm that +12 (or so) correction is not there which will also throw off your AFR pretty well. Adding more spark timing has the effect of leaning out, which makes hotter exhaust, which ties into the theory of Cat-Light-off causing the lean condition to light off the cats, and then it cuts out after 3 mins. That didn't make complete sense, but I think you've got the idea. I've only got 5 hours of sleep the whole weekend....my brain's a little mushed...freakin FTX's.
Just throwing some more ideas out there!
Best Regards,
Adrian