Ok guys, heres the deal, and i hope you dont freak on me cause ive been confused about this alot.

My set up:
Drag turbo running 5psi, 12:1 FMU (Vortech), 310's, aux inline fuel pump.

Heres the deal:
I was driving to my GFs house the other night on the highway, it was really snowy out, so i was doing about 55 in 5th gear, sitting just at about 3900-4100 RPMS. sometimes i bog at 4000rpms, like i get hesitation, and i go lean, then all of the sudden i go rich and i get fuel and i get boost. i dont know what this is, anyways i was driving at this speed for about 45 minutes, not once boosting or anything. then it happened, my A/F guage went batty, it was flashing and going ALL over the place, i was getting extreme hesitation in my fuel delivery and i was having trouble mainting constant RPM speeds. i noticed also at times my boost gauge was having trouible mainting a constant vac pressure, it would jump to 10 then back to 15 in vac pressure. so i make it home shut it off and i go to sleep. Next day i start it up to only notice the same thing, having troubl idling, and having problems with fuel, it will stutter at speeds when i floor it, then suddenly the "Clog" or whatever is heeding my fuel will move and i will go rich and then i boost.

I KNOW I AM RUNNING RICH, i am getting the recalibration kit for my FMU for xmas. but in the past 4,000 miles ive never had this problem, DID I FOUL my plugs? is THIS the problem? please help my car goes off the road this week for winter and i want to get it sorted out before i leave, is it a plug issue? how long will plugs last when going THIS rich? please guys....im losing sleep

 

So you had this issue when you were in vaccuum? If that is the case the recal disc will have no effect. What is you idle fuel pressure? 310s at stock idle fuel pressure will idle, but should idle badly and bog a little under vac. I know that most people running 310s with no AFC usually set their idle pressures in the 20-30 psi range. Of course these are mostly JRSC people, but that would make no real difference.

 

no i would get the hesitation when i floor it to go into boost, it wont boost, it will hesitate......then its like someone flicked a switch and i get fuel, and i boost

 

check you IAC valve.. i'm getting a code for that right now with almost the same exact problem. It does a similar thing and finally i have a code after it got so bad...

also my car goes into safe mode... and starts freeking the hell out...

 

sounds logical.

 

that's also a fuel problem...you're running way too rich....check the turbo also to see if it's loose from the manifold

 

What exactly is the IAC valve? Where is it located?

 

IAC = idle air control valve,
it doesnt have a huge problem just sitting there, its not really an IDLE problem....its more of a fuel problem.

When i am at 4000 RPMS and i floor it, boost doesnt come on right away, my A/F shoots to LEAN.....and it hestitates, then it will almost like a like switch SNAP to rich and i will take off with neck snapping speed, WHAT IS CAUSING this???

also why would my turbo be lose from the manifold?

 

well, Art suggested that i disconnect my FMU and connect it back to how it was stock and see if it idles fine, if so then he thinks my FMU might be stuck open, in which case ill have to get a new one. but if this is NOT the problem what could it be?

i Took out my plugs today and they were PITCH BLACK, i assume this means cause they are so rich? so i sanded them down and tried to clean them, i put them back in and it ran a bit better.

Also i am having a problem with my A/F guage like i stated, its not just lighting up in a nice sequence back and forth anymore like it used to, its just flashing now and going absoultely battty.....what the hell is going on guys! please help

 

come on guys, help a brotha out

 

It's possible that your O2 sensor is coated just like your spark plugs from running so rich. If the O2 sensor can't get a good sense of what's going on in your engine, the ECU has a hell of a time gettin your fuel mixture right under vacuum.

 

I've been having a very similar problem since I installed my 440's. I'll be crusing along just fine, but if my throttle position drops to around 5-7%, the car will just randomly cut-off completley, like as if I suddenly released the accelerator, then out of nowhere it'll come right back like a switch. The funny thing is, when it does this (cuts out), my A/F gauge goes blank...then the car comes back and the A/F gauge lights up again..?? It won't happen if I'm over 8% throttle, it's only when i'm just barley giving it throttle (to keep up w/ slow moving traffic for ex.) and it's supremly annoying because my cars look like a damn bucking bull when it does this.. any idea's?

 

I love my Zdyne, i'm not trolling just saying that standalones are the way to go, no matter weather you're running 5 or 25 lbs, i'm only running 6 PSI. What more logical:

1 Troubleshooting all those check valves, fuel pumps, RRR, boost retard boxes, and vacume lines, and worring about blowing you **** up

2.) Plug in a ECU, tune with a laptop

 

So what I told you didnt work?

art

 

Anything yet?

art

 

do you have a fuel pressure gauge to tune with? You need to lean it out a little in the low end area...

get a B&M gauge and get your static f.p. to around 40-44psi...

 

could I get a b&m fuel pressure regulator and gauge to lean out in the lower rpms? I get bogging sometimes down low at partial throttle, could that help. I'm running stock injectors with my drag kit, 7psi with about 3 degrees retarded timing.

 

Curious about the Vortech...does it have a gain ****? My Cartech does. So when I back out the gain the fuel does not hit right away. Sometimes(this morning) my A/F went full tilt lean then like a switch it went rich. I think my gain is too far out for stock injectors. I had my gain all the way closed before and it worked pretty good.
If it doesn't have a gain know then nevermind.

 

Well the Cartech is adjustable and the Vortech is not. Vortech does make an adjustable FMU but its not the set rate FMU that comes with 100% of the drag kits.


art

 

I see, I always wondered about what FMU the Drag kit comes with because I have seen both on Vortech's website.

 

ok heres the latest update:

took off my FMU like you suggested art, connected it back to stock, and it idled much better, but then as soon as i gave it some throttle in neutral to see what would happen it went nuts again, and i got white smoke out the exhaust, but if i didnt touch the gas, it seemed to idle much better. help!!!!!!!! waht does this mean? also before i took it out, i couldnt even boost, i was driving around FULL LEAN, i didnt dare to leave VAC. helpppppp

 

Whens the last time you replaced your fuel filter?

Also, try NEW plugs, sanding electrodes can damage the plugs even though they look clean.

Its also worth saying...check for vacuum leaks



[Modified by greyzone, 9:37 PM 12/18/2001]

 

i could replace my fuel filter, the plugs are only 3,000 miles old


and how could a vac leak cause me to not get my fuel?

AND NOW when i touch the gas i get WHITE SMOKE!


[Modified by NYb16, 9:54 PM 12/18/2001]

 

vacuum leaks can cause all kinds of wierd **** to happen...check for them simply to eliminate that issue, often you just have to go through a pain in the *** process of elimination...and the issue with the plugs isn't age, sanding them CAN damage them, not that it did, but it can.

I've learned the hard way that is often the simple **** that I overlook thats causing the problem...rarely is it something "hi tech."

And I didnt see you repsond to the comment above about your o2 sensor possibly being fouled...that was a really good suggestion, check it out, Fouled 02 and your ECU could be freaking out with no idea what kinda of fuel/duty cycles to send.



[Modified by greyzone, 10:05 PM 12/18/2001]

 

i could replace my fuel filter, the plugs are only 3,000 miles old


and how could a vac leak cause me to not get my fuel?