The car idles lean when I first start it. It does this for a minute or two and when warmed up it idles at stoich. Comanded reads right and even the IPW is the same as when warm. What is going on? Only at idle too. If I drive the car everything seams fine.
Last edited by BADSZ28; 10-06-2008 at 02:01 PM.
How lean is it?
2003 Z06
Forged 347
PTE Billet 67/65 Turbos
FMIC / Dual 50mm Tial BOV's
ID 1000 Injectors
RSI Stage 4 Fuel System
07 Z06 Cam
Tripple Nozzle Meth
ACT Twin disk clutch
25# Boost
Your Open Loop F/A vs. Coolant Temp vs. Map table is set to stoich. Take a look at a stock one. This table provides the 'richer' while the engine is warming up, until it goes into closed loop and the O2 sensors trim things to stoich.
Best regards,
Bill
Silver 2003 C5 roadster, M6, Euro red/amber tails, Z06 Ti mufflers, Z06 2 cat H-pipe, Z06 airbox, and HPTuners s/w - available to any Corvette or other GM vehicle in Calgary, and also for Ford and Dodge products, including Cummins
OL (and really in SD) you have to set the OLFA table up correctly. Not so bad with a MAF, but if you are OLSD, you will need to command colder ECTs a bit richer.
Sulski Performance Tuning
2000 WS6 M6 - LS6 (long block, refreshed top end), 10.8:1 CR, 90 mm ported FAST, Exo-Skel, 227/232 cam, QTP HVMC, EWP, GMMG, 9" w/4.11s
2018 Sierra SLT 5.3L A8 - Airaid intake tube, GM Borla catback, L86 Intake/Ported TB
What causes the engine to run leaner at startup though? I know my car is sucking in a ton of air because my IAC is high for about 30 seconds. I thought the startup fueling tables ADD fuel for the first 30 seconds.
2012 Chevy Cruze A6 1LT RS
Formerly - 2004 GTO, 2002 Z28, 2007 Colorado, 2008 Silverado
Work on your afterstsrt enrichment under (fuel section), as far min injector pluse you can increase that and your RPM & Map boundries way off need fixing..
cold air is denser air
Sulski Performance Tuning
2000 WS6 M6 - LS6 (long block, refreshed top end), 10.8:1 CR, 90 mm ported FAST, Exo-Skel, 227/232 cam, QTP HVMC, EWP, GMMG, 9" w/4.11s
2018 Sierra SLT 5.3L A8 - Airaid intake tube, GM Borla catback, L86 Intake/Ported TB
I never thought ofthe OLFA table. I was messing with afterstart enrichment and not getting anything. I will try that and tailor it to my needs.
Thanks guys.
A cold engine doesn't burn all the fuel put in the combustion chamber, plus like what was already said, cold air is denser, so more needs to be put in at cold start up.
I put in the stock values at 140* and below and that fixed it. Now it is way rich. Is there a histogram for logging AFR% error for OLFA table?
Don't log AFR error as they will most likely be huge. Just look at the actual AFR at an ECT and raise or lower the commanded AFR until you get where you want. Best way is to manually do this from a cold start, then go back and look at those numbers, then put them in the OLFA table.
Sulski Performance Tuning
2000 WS6 M6 - LS6 (long block, refreshed top end), 10.8:1 CR, 90 mm ported FAST, Exo-Skel, 227/232 cam, QTP HVMC, EWP, GMMG, 9" w/4.11s
2018 Sierra SLT 5.3L A8 - Airaid intake tube, GM Borla catback, L86 Intake/Ported TB
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