The past 2 weeks I have noticed my GSR running dead lean and sort of hitting a brick wall. I have an autometer A/F gauge, and though it isn't the most accurate in the world, it still is showing absolutely no variation in the A/F and will be stuck at the lowest red mark. The car feels like it isn't getting any fuel at all and I have to blip the throttle to make the car go back to normal. The problem doesn't occur every time I drive the car, but when it is happening it continues to do it for the duration of my drive.
I have been told this could be my primary 02 sensor crapping out. At part throttle it is in closed loop and the ecu is calibrating strictly off the primary 02, which is going south and not being able to give me the proper fuel?

I appreciate any help, this is quite annoying

 

are you running any kind of fuel management, if so what....

 

I have 290cc prelude injectors and a Cartech FMU running a 3:1 rise rate. My static Fuel Pressure is 38psi.

-Two weeks ago I installed my stock muffler on to my Apex 2.25" B-Pipe, changed my blower belt, and installed new spark plugs. The next day I noticed this hesitation problem. I also pulled my gauges out to check on them and then put them back in the A-Pillar. I thought maybe I had a vac leak from screwing with my boost gauge, so I disconnected it, but that wasn't the culprit.

 

if you are running 290cc injectors, without any fuel management, you are going to be rich as hell in part throttle... get uberdata, honda, or even the VAFC hack to scale down the fuel values.

 

I can see what you're saying, but I'm definitely not o n the ultra rich side of things. Maybe a tad rich, but nothing that has ever hurt my performance, made my plugs black, or thrown black smoke out the tail pipe. I have the 3:1 Cartech and an AEM FPR doing the fuel adjustment duties. I've been running the 290cc setup for 50k miles and my plugs are always grey/brown, this problem just came up 2 weeks ago. This was a common setup for higher boost level supercharged cars back in the day and has been proven to work quite well. I've had the blower setup for 6 years.

Bump

 

Your part throttle bog sounds like over fueling, not a lean condition. This is common with a big injector/FMU/no fuel management condition. My friends JRSC Prelude as the same issue at low/mid throttle at low rpm bc of the FMU.

As soon as your on the throttle hard the fuel pressure jumps up to the max, as it would if you were WOT. There is simply not enough air to burn this much fuel so for that second or so, your pig rich and hesitate. If you had an incabin fuel pressure gauge you could see this. Get a wideband and do a big burn out with your Viper on top of that worthless Autometer narrow band AFR guage.

 

Like I said above, I've been running this setup for quite a long time now and have never had any of these problems. This is definitely a mechanical or electrical problem that has arisen in the past 14 days. Something has given up the ghost and isn't operating properly. What you are describing is more of a rich condition where there is a split second pause between the FPR and the FMU picking up fuel duties. Yes, then there is typically a rush of fuel and the car bogs, but this is different. This isnt occuring between static and boost. This is occuring at say for example; 60mph in 5th gear at 3500RPM....the car will go completely lean. I can make it do this for a solid 30 seconds or more if I want to. It's as if it is hitting a wall and there is no fuel going in.

Btw, I do have an in-cabin fuel pressure gauge.

 

your fuel management is ghetto at best, personally i think your lucky you ever had it running good at part throttle. But assuming your not running rich (get a wideband) check your ignition timing

 

Ghetto, yeah probably, but when I was in to this stuff that was the only option at the time, besides an EFI PMS. Hondata hadn't even come out then. Many folks have run setups like this and have had little problem. At this point I have no desire to buy high priced electronics for the car. It has run correctly for a long long time and there has to be a simple fix for this issue..

Thanks and keep the suggestions coming.

 

Bump

 

Exact same **** is happening to my car...you will be driving slow or at a low part throttle-usually less than 20%and all the sudden the car will die out like no spark or something and then if you push the gas down more it jumps then drives normal...the only thing differnt from me is im running Hondata...FRESHLY tunedthis sucks

 

I might buy a new primary 02 and see if this fixes the problem. I want to get some expert opinion on this though.

 

hey anthony my car is doing the same an i am also running hondata. mine is doing it bad. so the point that it stutters. i do think that it is running rich, but i dont know why.

 

What is really feels like In My Opinion is a igniton cut but...i can see where is is possibly my fuel wheras i have 440s and runnng a really low duty cycle and high pressure...i have no idea why it was tuned on high pressure :/

 

Also,

Anyone think these problems could be caused by:

Bad TPS??
Bad AEM FPR??

 

i have this problem in a car im working on. it was so bad that at anything less than 50% throttle it would hardly want to go at all...the air fuel gage was reading super lean when it does it...i changed the o2 sensor and so far the problem has not surfaced. usually it would surface right when the car warms up. hopefully that was the problem...

 

My problem typically seems to occur on my drive home from work, but not to work. It never tends to last longer than 15 minutes or so. 99% of the time it will only occur when Im cruising down the road at 50-60mph with my foot barely on the gas.

 

This exact same thing is happening to me, so I'm bringing this back from the dead in hopes to get an answer.

PLEASE HELP!!!!!!!!!!!!!!!

My car has been doing this for over a year now, and it really bugs the **** out of me. I have a 95' b18c jdm gsr swap in my ej.
I have replaced:
1. fuel filter
2. fuel injectors (4)
3. Practically every sensor in the car.

I don't beleive that it is the fuel pump, because the pump was working fine just before I did the swap and immediately after the swap this started to happen. I've tested the fpr, by the helms manual and everything seems perfect. Any help will be appreciated.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CROM &raquo;</TD></TR><TR><TD CLASS="quote"> This isnt occuring between static and boost. This is occuring at say for example; 60mph in 5th gear at 3500RPM....the car will go completely lean. </TD></TR></TABLE> hmmm

 

yeas, only happens when my foot is barely on the gas...

 

me too and I drive a boosted Tiburon! car runs lean when i have about 5% throttle
and hesitates..

 

I am suffering from the exact same symptoms. Partial throttle, hessitation, clears momentarily if throtle is blipped. Doesn't allways happen, but when it does, it continues the remainder of the trip. Seems to start often after I hold WOT for a few seconds. I have had the autometer gauge for years, and am very familiar with the normal readout at partial throtle. When this problem occurs, instead of cycling back and forth, the reading are scattered all over the scale and resembles a multi colored strobe light. There is also a a/f ratio monitor in my turbo timer which just goes blank while happening. I had this problem once, before I installed the turbo, which had gotten to the point CROM was describing, where it would get stuck lean and die off, untill you hit the throttle. Durring the turbo install I put in a different O2 sensor, but now problem is resurfacing. Could this just be a failing O2 sensor? How long should they last? Why would it run normal sometimes? If anyone can help, I would greatly appreciate. This is extreemly fustrating.
BTW: Drag gen III on B18c, stock ECU & injectors, Vortec FMU from the kit.
Thanks

 

ttt, i also have the same problem.....

 

add me to the club, just put my head back on and i got this problem also

 

same problem here too...