revhardallday

iTrader: (1)

i just got 1600cc and 850cc injectors installed with aero motive fpr fuel pressuer is 38psi when idleing.

mods:
to4z single turbo
greddy fmic
greddy bov
greddy charge pipe
pfc with comander
no cats hks cat back
wideband, boost gauge


the idle is shaky
my wideband reads 10.2:1 at idle
muffler is puffing black smoke

car ran fine before with same setup and stock injectors at 7psi.. ran awsome for 2 years...

the car is a 94 fd3s.

im trying to get the a/f ratio to about 12:1 so i can drive it to a tune shop


also i put new plugs in and the seem to foul up fast after idleing for 6 mins the car wont start anymore unless it sits over night..

Marek

iTrader: (2)

If you haven't changed the PFC to accept the new injectors that could be the problem. I've heard of issues with people running the 850s in the primary spot, such as a being difficult to idle. If you are just trying to get it to a shop, you could adjust the area of your map where you idle/cruise and lower all the inj values to 0.647 the normal value. This will let you correct for your overly large injectors. I wouldn't go into boost with this setup though.

If you have access to a datalogit you could do most of the change yourself.

Either that or just tow it to the shop.

cpnneeda

iTrader: (1)

Did you set Fuel Pressure with the Vacuum Hose off the FPR? Also, you are gonna need to change the settings in the PFC for the injectors. If you were running stockers, the PFC doesn't know you have installed new injectors. If I am not mistaken you will need a Datalogit to change the Secondaries to 1600's but you should be able to change the Primaries with the Commander.

TwinCharged RX7

iTrader: (14)

Adjust your PFC, you can't run bigger injectors with the same fuel settings as stock injectors. They receive the same signal, but are bigger so dump more fuel. If you just want to get it to a shop you don't need to tune the secondaries, they only come on later in the rpm range, and if they do come on during your drive to a shop your rpm's will be higher and it won't flood/foul the plugs so easy if you do get too much fuel.

revhardallday

iTrader: (1)

i changed the injector settings on the pfc to 850cc and 1500cc because the pfc wont go to 1600cc.

so my primaries are 850cc and on my pfc i put them to 850cc is that all i have to do? cause it still runs the same.

i had some one change the fuel % on the pfc when i had stock injectors so it would pump more fuel... im thinking i can do the same by taking away fuel since the injectors are bigger.

also it wont rev pass 3k when it hits 3k it surgers slowly from 2k to 3k while holding the gas down

DaleClark

iTrader: (55)

If memory serves, that fuel pressure is way too high. Try dropping the fuel pressure down.

Dale

TwinCharged RX7

iTrader: (14)

are the injectors brand new, if they are used maybe one is stuck.

Were the plugs fouled badly on both the front and rear rotors, that might tell you if its a problem with a single injector.

GoodfellaFD3S

iTrader: (213)

Your idle fuel pressure should be more like 28-29 psi.

revhardallday

iTrader: (1)

everything is brand new got the altimate kg kit from rx7store.

all 4 plugs where fouled pretty bad.

im gonna drop the fuel pressure to 28psi at idle. its at 38 right now way to high from what i was just told.

any idea about the surging from 2k to 3k while stepping on the gas peddle surges really slow

DaleClark

iTrader: (55)

All bets are off until you get the fuel pressure right. With high fuel pressure, any tuning or whatnot you try and do will be incorrect.

Dale

revhardallday

iTrader: (1)

ok what do i set the secondaries to? the pfc only goes to 1500cc and i have 1600cc???

also what ur saying about the secondaries coming on later around 5k ur saying they just sit there and dont fire any fuel at all untill a certain rpm?

revhardallday

iTrader: (1)

i hear you, that makes perfect sense

MSilk

iTrader: (1)

What about the MAP sensor? is it hooked up? hose in good shape. I am just thinking that black smoke and rough shaky idle was what mine did when I unhooked the MAP.

Just throwing this out there

Mike

revhardallday

iTrader: (1)

map sensor is good plugged in and and has a new vaccum hose on it also has a small filter in line..

no_more_rice

I have 850 primaries w/ a PFC and my car idles fine but it's pretty rich - mid 11s

Just get it tuned as soon as you can

revhardallday

iTrader: (1)

whats ur fuel pressure set at at idle? thanks

no_more_rice

I think it's about 30-32 at idle but haven't checked recently

arghx

iTrader: (3)

The fuel pressure should be set without vacuum being applied to the regulator.

One way to do it is to put the key in the "ON" position (engine off) and jumper the GND and F/P terminals in the diagnostic box. That will pressurize the fuel system. Then set the fuel pressure. 36psi, 38psi, 40psi, and 43.5psi are common numbers. Most common would probably be 40psi.

revhardallday

iTrader: (1)

ok thanks for the info ill do it as soon as i get home.... i will keep u guys updated!

TwinCharged RX7

iTrader: (14)

The secondaries are usually staged, not 5k rpm though. I think mine come on just under 3k, and yes i'm saying they just sit there and don't fire until then, so they shouldn't be a factor with your idle.

Without vacuum to my FPR, it sits right at 40psi

grimple1

iTrader: (1)

time to purchase chuck's tuning notes and get in on the yahoo! PFC tuning group. after you get your fuel pressure set, you should take a look at arghx's posting.

https://www.rx7club.com/showthread.p...highlight=idle

revhardallday

iTrader: (1)

i turned the fuel pressure down but it didnt do much

also all the plugs for the twins were all cut off the harness.

this is what my pim voltage reads. some one changed it when i had the stock injectors

PIM 1.0V 120%
PIM 1.5V 120%
PIM 2.0V 115%
PIM 2.5V 115%
PIM 3.0V 110%
PIM 3.5V 110%
PIM 4.0V 105%
PIM 4.5V 105%

cpnneeda

iTrader: (1)

Set your fuel pressure on the regulator to 40, with the vacuum hose off, and leave it.

Change all those PIM's down to 100, with the exception of 4V and 4.5V. With the 850's, you need to drop them lower. I'd say start at 90% with both of them, and work your way down until you get the idle you want.

And for some reason, I thought this was you.
https://www.rx7club.com/power-fc-forum-47/thank-you-cewrx7r1-907387/

Since its not, you should send him a PM to find out exactly what he did. I believe it will help you too. Although, not sure if it can be done from the commander. But it's worth having in case someone with a Datalogit crosses your path.

revhardallday

iTrader: (1)

thank u i will try it tomorrow.

also in neutral the car wont rev pass 2k???

it revs to 2k then the turbo goes whooooooosh and revs back to 2k and then the turbo goes whoooooooooosh and keeps doing it over and over again untill i let off the gas,

my boost gauge reads 10 vaccum while idleling at 1k but before the injectors upgrade it read 20 vaccuum at 1k idle

cpnneeda

iTrader: (1)

I don't want to sound mean so bare with me.

Download the manual above. Print it out or not. READ IT. READ IT AGAIN. READ IT A THIRD TIME. Then go out to your car, manual in hand, and go through the manual page by page. Once you do that, then you can start trouble shooting.

Some of the more experienced guys don't, but I know I still have my copy in my work bag, that I can read anytime I can't get to a computer. It comes in handy and has A LOT of good information in there.

Take advantage of it.