Cold ECT's, no start, too rich, too dumb to figure out why...
10-08-2013, 10:45 AM
#1
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Cold ECT's, no start, too rich, too dumb to figure out why... 408 lq
11.5:1
243's worked
Comp Cam (click for card)
Fast 102 intake
Fast 102 throttle body
42lb injectors
4l80e FMVB (no transmission inputs to ECU)
HPtuners SD operating system
no maf, no O2's
With throttle input I can get it up to operating temp and get it idling solid and restarting fine with the TB screw adjusted so IAC counts are around 40-50. I've logged my RAF best I can since it will only idle past 140 degrees or so.
When I go to start it up cold, about 75 degrees right now, it hits for a half a second and goes rich 11,10,9 until it floods out. If I give it throttle input to get it through the first 10 seconds or so it'll idle by itself but goes lean 16,17,18. It does this until I keep throttle input in it until about 130-140 degrees and then it settles out at 14.7 and idles perfectly at 850.
I'm at 60 on the VE to get it to idle cold (if it stays at 52 it goes really lean as described above) at 14 and about 52 to get it to idle hot at 14.
Things I've screwed with:
Verified the IAC works out of the TB - it does
Changed just about every sensor out
Checked vacuum leeks at hot idle with propane - none to be found
TPS is at 0% with a voltage of around .47 to get my IAC's at 50 at hot idle
OLFA tables - leaned them out as far as it'll go, .81.
IAC vs effective area - moved it left and right, no noticeable effect
Put really high numbers in the RAF at the colder ECT's to get the IAC to force fully open at start - still goes rich and dies
Put really high numbers in frictional/startup airflows - no change
Cut down on the the starter enrichments - no change
I'm sure there's more, but can't recall at the moment.
Let me know if you need more info.
As I finish typing this I realize i'm on the wrong computer to attach my file. Be back in a second...
11.5:1
243's worked
Comp Cam (click for card)
Fast 102 intake
Fast 102 throttle body
42lb injectors
4l80e FMVB (no transmission inputs to ECU)
HPtuners SD operating system
no maf, no O2's
With throttle input I can get it up to operating temp and get it idling solid and restarting fine with the TB screw adjusted so IAC counts are around 40-50. I've logged my RAF best I can since it will only idle past 140 degrees or so.
When I go to start it up cold, about 75 degrees right now, it hits for a half a second and goes rich 11,10,9 until it floods out. If I give it throttle input to get it through the first 10 seconds or so it'll idle by itself but goes lean 16,17,18. It does this until I keep throttle input in it until about 130-140 degrees and then it settles out at 14.7 and idles perfectly at 850.
I'm at 60 on the VE to get it to idle cold (if it stays at 52 it goes really lean as described above) at 14 and about 52 to get it to idle hot at 14.
Things I've screwed with:
Verified the IAC works out of the TB - it does
Changed just about every sensor out
Checked vacuum leeks at hot idle with propane - none to be found
TPS is at 0% with a voltage of around .47 to get my IAC's at 50 at hot idle
OLFA tables - leaned them out as far as it'll go, .81.
IAC vs effective area - moved it left and right, no noticeable effect
Put really high numbers in the RAF at the colder ECT's to get the IAC to force fully open at start - still goes rich and dies
Put really high numbers in frictional/startup airflows - no change
Cut down on the the starter enrichments - no change
I'm sure there's more, but can't recall at the moment.
Let me know if you need more info.
As I finish typing this I realize i'm on the wrong computer to attach my file. Be back in a second...
10-08-2013, 10:58 AM
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Here's the file.
I've been running this tune all season and just dealing with the cold start issue. Seems to run fine other than that. The guy that tuned it had the PE all over the place when he did the VE table so it might look a little weird I guess. I didn't know enough about it to question it when he did it.
$100 paypal to the person who fixes it.
EDIT: This should be the file as it's been running the past season before I started screwing around with stuff I probably shouldn't have.
I've been running this tune all season and just dealing with the cold start issue. Seems to run fine other than that. The guy that tuned it had the PE all over the place when he did the VE table so it might look a little weird I guess. I didn't know enough about it to question it when he did it.
$100 paypal to the person who fixes it.
EDIT: This should be the file as it's been running the past season before I started screwing around with stuff I probably shouldn't have.
11-13-2013, 10:43 AM
#5
My car has displayed similar behavior. Runs like *** cold but once warm seems to be fine. This is typically only an issue the first time its started that day. I have to let it warm up a lot then turn the engine off long enough the pcm resets then turn it back on and it works.
I'm getting ready to try porting the IAC passage of the junk Fast 90mm tb and see if that helps any.
I'm getting ready to try porting the IAC passage of the junk Fast 90mm tb and see if that helps any.
11-13-2013, 12:13 PM
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Even after a chassis dyno tune with correct VE tables mine still won't fire under 120 degrees without throttle input. I've been all over the software. I kinda gave up. It's a race car and I guess I'll just deal with it for now.
11-14-2013, 09:50 PM
#7
TECH Fanatic
A few things that I see that could could possibly help...
1. Airflow-->General-->Cranking VE vs. MAP vs. RPM does not match Main VE - this should generally match your main VE like the idle spark advance should match the main spark advance tables (spark advance match fine).
2. Fuel-->Open&Closed Loop-->Open Loop EQ Ratio (top left corner) - If you have the stock values for this I would reapply them and tweak it from there. You have a 1.15 multiplier to 86* ECT and 1.0 from that point on. A blanket 1.15 enrichment multiplier is TOO much across the board.
3. Idle-->Airflow-->Base Running Idle Airflow (Idle Airflow Tab) - These appear to be stock values. I would multiply the entire row by 1.6 and use that as a starting point. I would also set the target RPM at 1250 when it's colder.
4. Spark-->Advance-->ECT Spark-->"Base" Tab - Zeroize the negative timing values
1. Airflow-->General-->Cranking VE vs. MAP vs. RPM does not match Main VE - this should generally match your main VE like the idle spark advance should match the main spark advance tables (spark advance match fine).
2. Fuel-->Open&Closed Loop-->Open Loop EQ Ratio (top left corner) - If you have the stock values for this I would reapply them and tweak it from there. You have a 1.15 multiplier to 86* ECT and 1.0 from that point on. A blanket 1.15 enrichment multiplier is TOO much across the board.
3. Idle-->Airflow-->Base Running Idle Airflow (Idle Airflow Tab) - These appear to be stock values. I would multiply the entire row by 1.6 and use that as a starting point. I would also set the target RPM at 1250 when it's colder.
4. Spark-->Advance-->ECT Spark-->"Base" Tab - Zeroize the negative timing values