Help Me Diagnose Fueling Issue. O2s?
09-15-2013, 11:11 PM
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Help Me Diagnose Fueling Issue. O2s? Hey guys. I've got a weird one.
02 ls1 with pacesetter lt's, tsp duals, tsp 228r cam, 3200 converter, bolt ons.
The car was street tuned after the cam went in and everything was cool. However, slowly over time the low speed driveability started to decline. I can revert it back to acting right by unplugging the battery to reset the pcm. At first this worked for a couple weeks. Now it works for a couple hours before it starts to act up again.
No SES light, factory o2 sensors(68k miles), rears tuned out, extensions on the fronts.
In certain temp ranges(ie when the engine is sorta warm, or totally cold) the low speed driveability is really bad. Pulling up to stoplights I have to pop it in neutral to keep the revs up or the idle will surge up, then crash down and sometimes stall. Reverse is even worse.It also smells more rich than normal when it's acting up.
The surging is really what has me puzzled. I can cruise down a street or the highway and you would never know if has any issues, part throttle, WOT, all perfect...then you pull up to a stop light and get on the brakes hard under 15mph, or sit in stop and go traffic where you're on the gas, then off the gas and onto the brake quickly and the rpms start to roller coaster up and down a bit. Aprox 1000rpm range of motion from like 500-1500(I think...it's been a while since I drove it). The harder you get on the brakes the more likely it will start to surge and dip. If I very gingerly roll to a stop it won't usually act up.
Has anyone has a similar issue? Thanks in advance.
02 ls1 with pacesetter lt's, tsp duals, tsp 228r cam, 3200 converter, bolt ons.
The car was street tuned after the cam went in and everything was cool. However, slowly over time the low speed driveability started to decline. I can revert it back to acting right by unplugging the battery to reset the pcm. At first this worked for a couple weeks. Now it works for a couple hours before it starts to act up again.
No SES light, factory o2 sensors(68k miles), rears tuned out, extensions on the fronts.
In certain temp ranges(ie when the engine is sorta warm, or totally cold) the low speed driveability is really bad. Pulling up to stoplights I have to pop it in neutral to keep the revs up or the idle will surge up, then crash down and sometimes stall. Reverse is even worse.It also smells more rich than normal when it's acting up.
The surging is really what has me puzzled. I can cruise down a street or the highway and you would never know if has any issues, part throttle, WOT, all perfect...then you pull up to a stop light and get on the brakes hard under 15mph, or sit in stop and go traffic where you're on the gas, then off the gas and onto the brake quickly and the rpms start to roller coaster up and down a bit. Aprox 1000rpm range of motion from like 500-1500(I think...it's been a while since I drove it). The harder you get on the brakes the more likely it will start to surge and dip. If I very gingerly roll to a stop it won't usually act up.
Has anyone has a similar issue? Thanks in advance.
09-19-2013, 03:03 PM
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Well when talking to my tuner he pointed my in the direction of o2's. It makes sense with the way it's acting. The way I see it it's a 50 dollar gamble and when I am looking at 400+ and a 4 hour drive to a tuner just to check the trims I don't have a lot of good options.