AFR Question

[3.8L V-8 eater]

Hi, to all

I just installed my PLX wideband kit with a stand alone gauge.....I noticed once the car got up to operating temp that the idle was rich....I started playing around with base fuel pressure to bring the idle to 14.7 give or take a few tenths.....Now that I have f. pressure where I want it the base f. pressure is now at 40 vac line off...Could this cause me to be lean at WOT dropping it down that low???

 

[kidglok]

if your car idles that lean then god bless, most are around 13-13.5

that can change wide open throttle a little bit, erics chips are set for 42 line off so if your at 40 that shouldnt be too bad. Id add a few clicks to WOT fuel and see what the wideband does.

 

[turbo nasty]

I second....Eric's chip is open loop idle.

Side question how does your 6262 spool on the foot brake with the 3k NLU stall.

 

[3.8L V-8 eater]

I second....Eric's chip is open loop idle.

Side question how does your 6262 spool on the foot brake with the 3k NHL stall.

I will add a little fuel to 3rd and see what the wideband shows...

As far as the spool would like it to be a little better, but I'm not real happy with this converter....Not very efficient up top and I'm driving through it!!!

 

[jasjamz]

I would put the fuel pressure at 43 line off and figure out why its rich. It could be a vacuum leak or a bad 02 sensor. Lowering the fuel pressure leans the car out across the entire fuel map. I wouldn't do that, especially on a pump gas car.

 

[turbo nasty]

I wouldn't say it leans it out across the whole band but it does cause the the ECM the add fuel across a lot of the table

 

[turbo nasty]

I will add a little fuel to 3rd and see what the wideband shows...

As far as the spool would like it to be a little better, but I'm not real happy with this converter....Not very efficient up top and I'm driving through it!!!

Cool...yeah the converters sometimes take 2 or 3 reworks to get right. I just ordered a 6262 Jb and have a Ptc non Lu 3200 and we shall see if it has decent boost response with that convertor.

 

[we4Mateo]

The TT chip should idle richer than 14.7 unless you had him enable closed loop idle but my TT chips always idled in the 13's as open loop idle is default (no correction). If closed loop is enabled, then the computer will adjust itself to get what it wants anyway. Therefore, your FP is probably too low. I adjust FP based on the BL's. If high, raise FP to lower BL's, if low, lower FP to raise BL's; a BL of 128 is centered and anything within 10 of that is acceptable. But you need to drive around and see where the BL's are at different parts of the map and not just at idle.

 

[3.8L V-8 eater]

Cool...yeah the converters sometimes take 2 or 3 reworks to get right. I just ordered a 6262 Jb and have a Ptc non Lu 3200 and we shall see if it has decent boost response with that convertor.

You'll be fine with the 3200...That's what my next converter will be a PTC 3200....

 

[3.8L V-8 eater]

The TT chip should idle richer than 14.7 unless you had him enable closed loop idle but my TT chips always idled in the 13's as open loop idle is default (no correction). If closed loop is enabled, then the computer will adjust itself to get what it wants anyway. Therefore, your FP is probably too low. I adjust FP based on the BL's. If high, raise FP to lower BL's, if low, lower FP to raise BL's; a BL of 128 is centered and anything within 10 of that is acceptable. But you need to drive around and see where the BL's are at different parts of the map and not just at idle.

I will set it back to 43 and watch BLM's....This chip is set for open loop idle and that's where it is although it can be disabled if disired.....

 

[forcefed3.8's]

Don't fall in love with the idea of 128 at idle. I have rarely seen it. As long as it isn't at the extremes, don't worry about it. Every car is different. Maybe the car doesn't want to be at 128 because the chip is off from what the engine wants. As long as the car drives fine, don't lose sleep over it. Besides idle BLM have no effect on WOT, and that is what really matters. 2nd place is last!!!