I've been having this problem for a while. Car was running fine when I got it. Now I will cruise fine at 14.7, but once I let off the throttle (and leave it in idle) my AFs will immediately go lean, as normal, then a second later jump back down to rich, like 10.5/11, and slowly climb back up, and be back to stoich about 15 seconds later. If I get back on the throttle while it's doing this, it'll be fine at stoich again.
If I'm getting on it, it's stoich until I get to higher RPMs (usually past 4K, where the SAFC starts) then it gets SUPER rich, 10s at first, then out of the range of my wideband past 5000 or 5500. My wideband was tuned a few months ago on a dyno, and all the A/F correction settings are the same as it was before. It should also be noteworthy that my car doesn't seem to be as fast as it was before.
Noteworthy:
1. I'm in TTC electronically, and have the 12v and EGR mods done.
2. The VPC MAP sensor (which requires the vaccum nipple facing down) was facing mostly up when I got the car, and during and after the tuning. Since then I have pointed it downwards, shortened all the vaccum lines, and limited how many T fittings are on the same vaccum source.
3. I have gotten NO ECU codes.
4. I have checked the VPC MAP sensor voltage with the engine off and it is normal.
5. The problem was worse (took longer for the A/Fs to climb back up) when the battery terminal was loose. This makes me think the problem is electrical.
What's my problem? Thanks a bunch in advance. PayPal $10 to whoever gives me a solution.
If I'm getting on it, it's stoich until I get to higher RPMs (usually past 4K, where the SAFC starts) then it gets SUPER rich, 10s at first, then out of the range of my wideband past 5000 or 5500. My wideband was tuned a few months ago on a dyno, and all the A/F correction settings are the same as it was before. It should also be noteworthy that my car doesn't seem to be as fast as it was before.
Noteworthy:
1. I'm in TTC electronically, and have the 12v and EGR mods done.
2. The VPC MAP sensor (which requires the vaccum nipple facing down) was facing mostly up when I got the car, and during and after the tuning. Since then I have pointed it downwards, shortened all the vaccum lines, and limited how many T fittings are on the same vaccum source.
3. I have gotten NO ECU codes.
4. I have checked the VPC MAP sensor voltage with the engine off and it is normal.
5. The problem was worse (took longer for the A/Fs to climb back up) when the battery terminal was loose. This makes me think the problem is electrical.
What's my problem? Thanks a bunch in advance. PayPal $10 to whoever gives me a solution.