Fuel Cut question

[wpg87turbo]

So I took your advice and have not put on the HKS FCD. Unfortuneatly in my last post I never really did get a solid respone to my question. The problem im having, is I hit fuel cut immediately upon changing gears. Sometimes between 1st and 2nd and almost always between 2nd and 3rd. Like I shift and the moment im back on the gas, fuel cut. Does not hit fuel cut under full boost (only running 9psi) and does not hit it at any other time. How can I diagnose this problem? Has anyone else experienced it? When checking for boost leaks, what do I spray down the hoses with? just water? I've already tested to propane torch method and no success. Please guys help me im losing races because of this lol.

 

[The Reaper]

Spray soapy water on the pipes. i had this samething happen and i just got a lex afm and 550's and an safc and it was cured. i dunno only thing i can think of is that it spikes when you bang the next gear????

 

[suprra_girl]

what mods have you done?

 

[wpg87turbo]

Intercooler hardpipes, 3" exhaust off the turbo, hks f-con w/GCC, and I've drilled out and backed out the screw in the factory MAF. I just find it weird that it doesnt do it under full boost, just when changing gears. And another thing I noticed, it doesn't do it when its cool outside, like under 10 celsius so I guess thats like 50's in fahrenheit. Anyone else have ideas?

 

[stratoayu]

check ur BOV and BOV hoses. (depending on what one your running)

 

[Nick M]

Are you hitting fuel cut or is it stalling or starting to stall?

 

[Clifton]

Run an FCD and be done with fuel cut. If you need an over boost safety of some sort for comfrot, you can easily make one with a NC presure switch and relay.

 

[wpg87turbo]

It doesn't stall or anything, just when I shift gears it hits FC not violently but enough that it kinda sputters for a very brief second. im running a HKS SSQV (a real one not a knock off) i'll check the hoses any other suggestions?

 

[suprra_girl]

i had the same when i used to drag race without a fcd, every time the car shifted i'd hit cut, i got a fcd, dyno'd.. fuel was fine, i was done with fuel cut hehe

 

[wpg87turbo]

OK so its established that now I want to put this FCD in my car. I know what wires its supposed to go to, but if someone could maybe show me a schematic or something along those lines to illustrate which wires im supposed to splice into for a 87-88 turbo. I'd really rather not just start hackin into my harness, so if someone has put one into there car and can show me which wires to splice that'd be great.

 

[bigaaron]

The fcon will allow you to go past the normal point at which you would hit fuel cut because it can drive the fuel injectors after the point where the ecu would cut them off. You need to use the fcd with a fcon. Now the other issue is it might be running super rich, do you have a wideband? I found that the fcon tuning was way off without an afc. I had an fcon and it never had a good idle and would bog down at the lower rpms. Maft is a far better option imho.

 

[Clifton]

OK so its established that now I want to put this FCD in my car. I know what wires its supposed to go to, but if someone could maybe show me a schematic or something along those lines to illustrate which wires im supposed to splice into for a 87-88 turbo. I'd really rather not just start hackin into my harness, so if someone has put one into there car and can show me which wires to splice that'd be great.

Here you go. http://www.supras.co.uk/resources/MkIII/tips/hksfcd.htm

 

[wpg87turbo]

Ya I also notice that at lower rpms it seems to idle like it has a heavy cam or something lol. Any recommendations on what I can set the GCC to? and thank you very much for the post clifton was very helpful.