Tuning startup fueling

PANDA

TCG Elite Member
TCG Premium
Event Coordinator
May 24, 2007
38,011
8,519
Wisconsin Northwoods
My car runs very rich on startup. (LTFT's -10+) Then slowly gets back to normal by the time the car reaches 180. Timing is also low on startup but gets back to normal in about a min. I know the car is supposed to run rich on startup but is there anything I can do to optimize this? I feel the car is just burning tons of gas warming up. :dunno:
 

Turbocharged400sbc

3800 & 4T80E > ALL
TCG Premium
Jun 16, 2007
32,541
15,849
hangover park IL
My car runs very rich on startup. (LTFT's -10+) Then slowly gets back to normal by the time the car reaches 180. Timing is also low on startup but gets back to normal in about a min. I know the car is supposed to run rich on startup but is there anything I can do to optimize this? I feel the car is just burning tons of gas warming up. :dunno:

there's alot to adjust but you have to do the diagnostics first to make sure ya change what needs to be.

do a few normal coldstart logs to 180* ect to get your open/closed loop baseline, then youll be unplugging your maf at cold start and logging what it does to fuelling at open/closed loop VE (so you can see whether it's a maf table related or more open loop table related), after a few logs then try lowering cold idle to your current 180* idle setting (this is generally a big part of cold start trim issues as your moving more air than normal) and taking a few more cold start logs.

after all of this it's also a good idea to check if O2 warmup is affecting things by heating up the o2 with a torch at the threaded base before a few cold starts and see how fast you go into closed loop (to see what the afr decay is doing via 02 values)

there's more but i have to work :pedobear:
 

10sec

I haz dat teddy bear smile.
TCG Premium
Jul 26, 2008
25,942
5,812
after all of this it's also a good idea to check if O2 warmup is affecting things by heating up the o2 with a torch at the threaded base before a few cold starts and see how fast you go into closed loop (to see what the afr decay is doing via 02 values)

This is panda's problem, he's got a lazy o2 that doesn't like to warm up. He is aware of this :squint:
 

Handsome Jesus

A V6? What a ripoff...
TCG Premium
Jun 9, 2007
9,211
239
Carpentersville, IL
there's alot to adjust but you have to do the diagnostics first to make sure ya change what needs to be.

do a few normal coldstart logs to 180* ect to get your open/closed loop baseline, then youll be unplugging your maf at cold start and logging what it does to fuelling at open/closed loop VE (so you can see whether it's a maf table related or more open loop table related), after a few logs then try lowering cold idle to your current 180* idle setting (this is generally a big part of cold start trim issues as your moving more air than normal) and taking a few more cold start logs.

after all of this it's also a good idea to check if O2 warmup is affecting things by heating up the o2 with a torch at the threaded base before a few cold starts and see how fast you go into closed loop (to see what the afr decay is doing via 02 values)

there's more but i have to work :pedobear:

5 gallons of gas burned at idle later and you might have some good data.
 

10sec

I haz dat teddy bear smile.
TCG Premium
Jul 26, 2008
25,942
5,812
RVR said it was because of the O2 placement on my TOG's. Ive tryed a few different O2's they all seem todo the same thing.

Well, you just answered your own question/concern, just let it be huh? Unless that o2 warms up quickly it's going to do that and moving the o2 to a different location just for this seems a tad bit silly don't you think? :ford:
 

PANDA

TCG Elite Member
TCG Premium
Event Coordinator
May 24, 2007
38,011
8,519
Wisconsin Northwoods
Well, you just answered your own question/concern, just let it be huh? Unless that o2 warms up quickly it's going to do that and moving the o2 to a different location just for this seems a tad bit silly don't you think? :ford:

If some tuning cant fix I will just have to let it be. Im just getting horrible gas mileage, and not just recently since the "change".
 
Old Thread: Hello . There have been no replies in this thread for 90 days.
Content in this thread may no longer be relevant. Consider starting a new thread to get fresh replies.

Thread Info