PFC
T04S
1680 cc secondaries

Any ideas what would cause it to fall on its *** anywhere near 0 or positive pressure.

 

check that fuel pump relay. I had a problem when i disconnected mine, but forgot to disconnect the ecu. I plugged it back in and it was just like hitting a wall. I had to reset the ecu and it was back to normal.

Amel

 

huh?

 

yeah reset the ecu..

 

reset my PFC? thats not going to solve anything

 

*raises hand and say :Me Me ME, i think i know that answer to this one*

I had a simular problem. When ever it came close to 0 or possitive pressure it just died. (no matter what gear or what rmp i was at)

It was the vacum hose connected to the(a?) Boost sensor.
Between the elbow and the torpedo wall(?) on driver side is a little gadget that says "Sensor - Boost". It should have two vacum hoses connected to it.
If it only have one,the engine just almost dies everytime you get near boost.

 

Yes, that's the Map sensor. Also known as boost sensor. E, that COULD be the problem. Give it a look. Make sure all the lines are plugged in, and the plug is tight. If it's only doing it when it sees pressure at the manifold, then it's directly related somehow.

 

Not the pressure sensor, it reads fine through the PFC

 

My guess is that one of your secondary injectors is not firing. Check the wiring and see if the injectors click when you apply 12v to their terminals.

If you go really light on the gas, can you drive the car over 4000 RPM?

-Max

 

It stumbles but yes i can....

 

I f i unhook the negative cable on my battery for about 15 to 20 seconds and hook it back up it then go and pump the gas pedal while cranking the car will then rev somretime s and run fine till i shut it off again i have no idea whats going on.the dealer just told me sorry we cant help you when they looked at it

 

It will if you're in limp mode!

(limp mode = runs fine, but fuel cuts when in boost)

 

limp mod also should equal check engine light.

 

incorrect.

^ takes my vote. (when you rev in nuetral do you hit a rev limit at 4500?)

if you had your injectors cleaned by RC, and they sat for a little while, they could be stuck. <--happen to me.

I assume you have the resistors for the 1680's...

another check would be the Fuel Pump (Speed) relay...

 

What is limp mode for and what makes it go into this mode

 

Does the PFC even have a limp mode? If he had the stock computer, I'd say that's the cause, but.....probably not with a PFC. I have read (I think on wade's site ???) that the PFC functions similarly to the stock computer as far as when secondaries come on etc, and on a stock computer, you can go well above 0 boost with out activating the secondaries. If I am correct about that, I doubt it's the secondaries sticking shut. Take a look at your injector duty cycle when this happens and see what is going on. Are you running anything different as far as ignition upgrades?

 

The PFC definitely has a limp mode. After installing 1200s and hi-flow fuel pump, my FD would stumble whenever going into boost, but drove fine when in vacuum (any RPM).
This drove me crazy thinking my secondaries weren't coming online, etc, but as soon as I reset the PFC, the problem went away. I was glad I tried that first

 

is there any certain procedures to resetting the computer or do i just unhook the battery for about 15 min. but it always comes back. And also when it does cut out the harder i push on the gas the farther my air/fuel guage burries itself to the lean side until it dissapears. But when i do get it set to where it runs fine by unhooking the battery it reads fine while getting on it . And also while driving down the road normally when its running fine the air/fuel guage fluctuates between the middle and lean. I wonder if the car can ever be fixed.

 

Did you ever get the problem fixed Ejmack? I'm having the same problems and its driving me nuts.

 

tuning