Hey guys,
If im not boosting -15vac to 0vac and I mash the petal or I just accelerate fast. My air/fuel goes all the way lean and I get 0 power, I have to take my foot off the gas a little so that I can accelerate, then as soon as I hit boost, My fp is just fine and my air/fuel shoots to the blue. Any suggestions? I know that my pump is fine because as soon as I hit boost my fuel jumps to where is should be...
TIA!



Nick
97RS
Custom IHI Stage2
Obx exhaust, Limo Tint,
Custom interior, Upper Strut Bar, Kenwood/pioneer stereo.

Whats your fuel static fuel pressure? What size injectors are you running? Have you tried messing around with the static pressure? How bout an S-AFC? Does this happen at any RPM?


ride__________95 Eclipse RS : 5 speed
power________Field SFC Hyper-R : Gude cams : Jeep TB : AFX UDP : ram air : test pipe : GST catback
suspention___Hurricane F/R lower strut ties : BOMZ F/R upper strut bars : ES inserts
sound________Kenwood KDC 5000 : Audiovox 8" sub toob - no sub amp(damnit!)
shizzle_______AutoCommand remote start : dual air horns : Caspers o2 simulator(rear)
incomming___Bosal header
Jeep TB writeup - http://www.dimensia.com:81/jimbo/JeepTBfor2gnt.html

Sounds like the ecu is sensing boost and is either trying to compensate, and it isn't reacting fast enough--causing that "stutter" during the transition. Do you have a ML or any type of FCD?

$10 bucks says he's got an HRC FPR and FCD.

Post your complete fuel system... otherwise we're just guessing. :)

Got that ten bucks ;)
I am running a vortech fmu and stock injectors. This again is only happening before boost!at any level of negative vac. It does not matter of rpm level, if I ease the pettal and get 0 to positive boost then I will get no fuel cut at all, and i can mash the petal and im fine. I almost dont think its fuel cut, I think its just lack of fuel. The transition to boost is great, and my fcd is the one from hrc. And I have a walbro high pressure pump.
thanks guys,
Nick
97RS
Custom IHI Stage2
Obx exhaust, Limo Tint,
Custom interior, Upper Strut Bar, Kenwood/pioneer stereo.

Here's $10 that says you're actually too rich instead of lean. If your A/F goes dead zero when you mash the gas from vacuum and you have no power, then my guess is too much fuel. I had this problem with my HRC FPR and stock injectors. If I slowly boosted, then I was fine. But if I mashed it from idle or light cruise, then it bogged and took several seconds to clear out the fuel and get spooling. A/F would go dead lean, so I though I had a lean spot. In my experience, O2 sensors will read near zero when you flood them with fuel. You might try lowering idle pressure (but make sure you still have enough fuel at full boost). This worked for me (along with switching to the S-FMU).

Corbin

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



Gimme fuel...Gimme fire...Gimme that which I desire

Thanx corbin, I appreciate it. I am going to see what I can do and then if all else fails I will just get a s-fmu.
Thanks everyone.

Nick
97RS
Custom IHI Stage2
Obx exhaust, Limo Tint,
Custom interior, Upper Strut Bar, Kenwood/pioneer stereo.