no start, fires with full throttle

[Danish88GT]

installed s/c, 255lbs pump, larger maf & injectors first she would start but idle was bad, now after going though all the vacuum lines replacing the ones that looked bad she started up first go bad idle at 7-900rpm so i thought i would try a test run but dident even get out the driveway before she died and now she wont start at all! if i give her full throttle she fires but no go.. any clues?
i've read surge list and looked around.. but cant seem to find an answer?
help help help

car is a california 88GT stock except for listed above

 

[TheBocSez]

Probably your larger injectors. Even with a "calibrated" maf, the fuel introduced at start up is not affected so its fairly common to have hard start issues with larger injectors without a tune to compensate at start up. When you floor the gas pedal while starting overrides the initial injection of fuel somehow. Or at least this is my understanding. Please forgive the lack of techincal terms. What MAf and injectors are you running? Also, you should check for codes to see what the EEC says in wrong.

 

[BK_CAULEY]

you holding it at full throttle at start up is cutting the injectors off. do you have any kind of adj fuel pressure regulator? or any kind of FMU?

 

[Danish88GT]

well i have a regulator that came with the novi.. on the return fuel line.. is that what you ask? its brand new! could that have anything to say? i'm not good a technical english..sorry
definatly need a tune up - but cant before the start of june.. (only one place here can do it)
just strange that it has gone from starting and idle (bad idle but idle) to getting worse and worse.. to now being ****ed
just dont make sense!

 

[BK_CAULEY]

well i have a regulator that came with the novi.. on the return fuel line.. is that what you ask? its brand new! could that have anything to say? i'm not good a technical english..sorry
definatly need a tune up - but cant before the start of june.. (only one place here can do it)
just strange that it has gone from starting and idle (bad idle but idle) to getting worse and worse.. to now being ****ed
just dont make sense!

the fmu should be on the supply line. it increases fuel pressure (by a givin manufacturers ratio) for every pound of boost added.

 

[Danish88GT]

could that be causing my problems?
before i installed the injectors the engine was running quite good after s/c install.. just with bad idle (was using the maf without inj. so figured, to get better idle - change inj)

 

[jrichker]

the fmu should be on the supply line. it increases fuel pressure (by a givin manufacturers ratio) for every pound of boost added.

That's true where a regulator is supposed to reduce pressure. Mustangs use a shunt regulated system that bypasses fuel back to the tank via a return line. Decreasing the amount of fuel that returns to the tank increases the fuel pressure.

A FMU is supposed to increase the fuel pressure, so it goes in the return line.

 

[BK_CAULEY]

That's true where a regulator is supposed to reduce pressure. Mustangs use a shunt regulated system that bypasses fuel back to the tank via a return line. Decreasing the amount of fuel that returns to the tank increases the fuel pressure.

A FMU is supposed to increase the fuel pressure, so it goes in the return line.

wow, learn something everyday. i think you just fixed a problem im having with one of my car's. thanks.

on a side note. i wish i knew as much about stangs as you jrichker.