injectors or fpr

[420a_BOOSTED]

i still havent figured out why its running so rich. my 02 sensor is on, i have an fmu, and a walbro 255 high psi fuel pump. and that idle problem is still there. i was told that my fpr could be defective or my injectors are bad. im leaning toward my injectors because when im building boost really fast my car sometimes gets a fuel cut around 2-4 psi then when i ease into the boost i can take it up to 8-9 psi. this is really wierd any suggestions

 

[BigRand]

Check the passenger side of the fuel rail to see if you have a fuel port tester.

If you do, pick up or borrow a fuel pressure tester, and run it to the tester and under your hook so you can see it from the winsheild while driving (need a passenger for this by the way)

See what your fuel pressure is at idle, and see what it is at WOT, also take a look and see what it is when you easy into boost instead of flooring it.

This should also tell your weather your problem is at the injectors or at the fpr in the back.

 

[420a_BOOSTED]

does this sound normal? i know a guy that put the basic turbo components and basic fuel parts on and his car runs fine i dont know the deal. i guess every dsm is different and they are all difficult in their own way. where can i get this tester at?

 

[BigRand]

well check your local autoparts store, if you can't find it there,

www.jegs.com will have one shipped out to u in 1=2 business days.

See if you know someone at a shop that might have one and let you borrow it ya know.

 

[420a_BOOSTED]

what it seems to me is that i dont have a good fuel/air mix. not enough air is getting to the engine to mix well with the fuel that makes sence. well after i do this fuel tester what is a way to fix this problem?

 

[VelocitàPaola]

Do you have an A/F gauge or something? The only way to know if your air/fuel ratio is off, is by a gauge like that.

I personally think it must be something with the FMU if your only hitting "fuel cut" under boost. I think Rand's suggestions will guide you to pin-pointing your problem. Follow his directions, and tell us exactly what your fuel pressures are at idle, 50% throttle, WOT, under vacuum, at 2-4psi of boost (while flooring it), 2-4psi of boost (while easing into it), and at 7psi of boost.

 

[420a_BOOSTED]

i do have an air fuel gauge what line do i hook it up to?

 

[420a_BOOSTED]

how could the fmu be installed incorrectly?

 

[VelocitàPaola]

The A/F gauge taps into one of the O2 sensor wires. Search for install instructions, it has been discussed many times before.

Practically, the only way the FMU can be installed incorrectly is if you were to reverse the IN and OUT ports. Other than that, I suppose there could also be some sort of internal damage that could be causing all this (degrading diaphragm, wrong size disk, improperly installed disk). If you can narrow your list of potential problems down to being FMU related, I would call Vortech for further troubleshooting.

 

[420a_BOOSTED]

it was my missing link i took it off and my car works fine. i head there were two alternatives for this was the other one a fcd?

 

[VelocitàPaola]

Yeah, the FCD is an electronic alternative. It's much better in my opinion. I can make you one if you want. Send me a PM if you're interested.

 

[420a_BOOSTED]

okay ill take you up on that offer. will 4g63 injectors fit on my car? we just put some on a turbo honda today so if they fit on that they should be able to fit on my car or no?

 

[VelocitàPaola]

They'll fit, but you'll need a resistor pack to get them to work right. The 4G63 uses low impedance injectors, while the 420A uses high impedance injectors.

 

[420a_BOOSTED]

what is a resistor pack and where can i get one from? how much? (rough estamite)