boost question..
 

I swear i Searched this first! Will a front secondary injector code on a 93 fd cause the car to not boost at all. I cleared the code to get it out of limp mode and started it to see and it runs better. just rich and no boost. Stupid noo-b question I'm sure but hey, I'm just living up to my title here!

no boost at all?
nope! ecu can lower boost levels but really they are a mechanical function.

have you checked the MAP sensor and all hose connections between the crossover pipe and elbow?

The ecu cannot lower boost...a limp home code will simply cut ignition/fuel to the motor.

You have a big boost leak to not be able to get any boost.

rynberg, while i'd have to say i admire your knowledge in all things FD
would you not agree that the ECU can regulate boost to 7psi by not actuating the turbo per-control and/or wastegate solenoids? hence, lowering boost?

No, I would not agree, because that's not how it works. The ecu operates the wastegate at a fixed duty cycle under WOT. On a stock car, this generates about 10 psi of boost. Once you do mods, your airflow increases and so does your boost levels....because the ecu is still at that fixed duty cycle. By removing the pills or unplugging the solenoids, you will hit 7 psi, because that is the wastegate "spring" pressure (or actuator pressure in reality).

Many older turbo cars had no form of boost control whatsoever, they just relied on the wastegate spring pressure.

gotcha! so the duty cycle of those solenoids is completely independant of limp mode etc?

another newie question, but I hav UIT off and I'm looking at the rat's nest, but how do I tell which injector I'm looking for? Basically which injector is the front secondary? I'm sorry if this is a stupid question, but this is the first time for me.

for one, the injectors are not on the rats nest... you know that right?!
ok, you have two injectors running into the centre iron - those are the primaries, its not those ones.

the secondaries are on the lower intake manifold - and you are looking for the one furtherest forwards towards the front of the engine.

fuel flows from the petrol tank, through the fuel pulsation dampener, through the primary injector rail, around a tube, into the secondary rail, through the fuel pressure regulator and back to the tank.

enjoy.

Right. Front Secondary is the injector most forward and passenger-side of the engine. Injectors are mostly buried by the rats nest, but this particular one may be accessible with that in place.

Dave

LOL yeah I know the injectors are not in the rat's nest, but that's all I could see. There was one injector visible on the passenger side and I was hoping that was it. The UIM was soaked with gas so I'm hoping that it was just a mechanical problem with the injector and not electrical. I haven't found any broken wires but quite a few vacuum hoses are trash. Thanks again everyone!

If you aren't familiar with how to pressurize the fuel rail without starting the car, I recommend you do that before closing it all back up. (Jumper F/P to GND in the little diagnosis box in front of the drivers side wheelwell, turn key to On).

FPD, injectors, injector o-rings are all common leak points - I wouldn't button anything back up without being confident those are all in excellent shape.

Dave

yeah, I do know how to work on cars and am familiar with fuel injection systems, just not on an FD. Vacuum lines and secondary this and that just gets indimidating to someone used to EEC-IV and V Mustangs. I will surely check for all of that though.

UPPER intake manifold soaked in gas?
sound like a leak in a fuel line more than an injector to me... probably takes a lot of pressure through a small split to get all the way up there.

The inside of the manifold was soaked. Like it was running very rich. It almost looked washed out on the runners

has anyone else had the same problem? I want to try to solve this for good!

Fuel pressure regulator. If the lines from the FPR to the FPR solenoid and check valve contain fuel, you need a new regulator.

If that's the case, someone has been selling them pretty cheap on eBay.

Dave