This is kinda a followup to Kiku post on the turbo forum, although this is turbo related I'm hoping that somebody might shed a little bit more on this topic.

I'm a turboed a/t and lately it seems that when I really get on the car (like mash the gas pedal) I look at my blinky blink a.f gauge and it's stuck on lean for a good 5-7 seconds before slamming over to the rich side. Now while it is on lean, it is SLOW as pizz, It feels like I'm n/a again until i see the a/f go to RICH than it slams me into the back of my seat. Here's the dilema, no matter how much I lean or richen my FPR (it's the Bell one that HRC uses) my fuel pressure always goes past a 100 psi....ok ok....I finally got my idle fuel pressure to be pretty steady (it's usually between 40-55) and now all this crap is happening, anyhow, does anybody have an idea of what's going on? Bad Plugs? Blown Injectors? give me a clue guys.



Mick

Shogun Body Kit
GTR Flared Wing
Arospeed Muffler
Half red-Clearm Tails
QT s-08 18"
Toyo Proxes Z4 215/18/35
..some turbo thingy me and Ray pieced together...

Oops forgot to mention, when I mash on the gas, and it is on lean, I hear the car spooling up but it has no go....i mean, it seems as the turbo is spooling (it is cause I hear the damn thing) but the car doesn't go anywhere, just another piece of info that might help.


Mick

Shogun Body Kit
GTR Flared Wing
Arospeed Muffler
Half red-Clear Tails
QT s-08 18"
Toyo Proxes Z4 215/18/35
..some turbo thingy me and Ray pieced together...

Are you using a fuel cut defenser?

Well, for now, DONT mash the gas if its running extremely lean for 5-7 seconds, thats very bad and will cause detonation and massive heat, have you checked your EGT's when its reading lean?

My engine runs lean for a few seconds while spooling at low rpm's... When are you mashing the gas?

Here's my theory:
Sometimes when you dump fuel all over the O2 sensor, it will read dead lean. Despite what the blinky LED's say, you might just be running pig rich for 5 seconds and bogging the engine. The kit has you running 50 psi at full vacuum and about 60 psi at 0 boost. Thats way more fuel than the engine needs at those points. But the ECU can compensate. Under closed loop conditions (low throttle) it uses the O2 sensor to figure out how rich you are running and adjust the fuel appropriately. When you mash the gas down (80-100% throttle), it stops reading the O2 sensor and just dumps however much fuel it thinks will work (based on the factory maps which don't account for high fuel pressures). So you run way rich until the engine can clear the gas out and really start spooling. My car did this too, when I had stock injectors and a HRC FPR.


Corbin

'95 ESI-T
HRC+FMIC+ETC...

my car does the exact same thing. fuel pressures are just right but i think the problem is that the ecu is compensating for the extra fuel and can't do it fast enough. it sees rich so it goes to lean and then it doesent see lean for a few seconds then it finally does and then bam it goes rich! sometimes when this happens it hurts my head cause the power is so violent. I am going to get larger injectors and lower the fuel pressure and see if this helps.
lates
james

my car lags too when i floor it, it bogs and then decides to start moving, no turbo, i figured its 'tune up' related or something

Dino, yes I do have the FCD,
James, what size injectors are you going with? I got a friend with some stock 440's (I think) off his 1st gen gsx and he's giving them away, Will they fit? also I'm assuming I need a SAFC? can't I just get slightly bigger injectors and run it stock, like umm...maybe 270's? let me konw


Mick

Shogun Body Kit
GTR Flared Wing
Arospeed Muffler
Half red-Clearm Tails
QT s-08 18"
Toyo Proxes Z4 215/18/35
..some turbo thingy me and Ray pieced together...

i was thinking of going 310 or 370 cc/min. i do not believe 4g63 injectors will work. i heard that our ecu can handle 270's without an afc, but don't quote me. i'll let you know how things work. anyone know what rise rates are achievable with the stock HRC FPR like when the screw is turned all the way in and all the way out?
lates
james