fuel cut or what?

[stratplayer24]

got a 90 gsx, all parts are listed on the profile. got 560 injectors, 255 fuel pump, FPR kit, safc, and big 16g running 21 psi...i can redline 1st gear, 2nd gear, but when i hit about 5500 RPM's it cuts out like i hit fuel cut or something. my Air fuel ratios are good (reading 10.0 on the wide band). what coud be causing this?

also when it cuts out i'll shift into fourth gear and floor it again, ill be at about 3500-3700 RPM's but my turbo won't hit full spool till like 4000 does that sound right? it's lagging like it were a 70 trim. .

any help is great! thanks, chris.

 

[gofer]

Your AEM WB will only read a 10:1 AFR, thats the richest it will go. It sounds to me like your going so damn rich your bogging, your rear bumper should be proof of this. Just check the rear bumper just above the exhaust and see if theres any black smoke staining it. Lean things out a bit and try to get the WB to hover around a 10.5~10.6:1 AFR after 4k (full boost), because right now if its showing a 10:1 AFR it could actually be a 8:1 since thats thats the lowest it'll read.

The 16g should hit full boost around 3.8k to 4k depending on port work and your exhaust setup, and of course the condition of the turbo.

 

[stratplayer24]

Your AEM WB will only read a 10:1 AFR, thats the richest it will go. It sounds to me like your going so damn rich your bogging, your rear bumper should be proof of this. Just check the rear bumper just above the exhaust and see if theres any black smoke staining it. Lean things out a bit and try to get the WB to hover around a 10.5~10.6:1 AFR after 4k (full boost), because right now if its showing a 10:1 AFR it could actually be a 8:1 since thats thats the lowest it'll read.

The 16g should hit full boost around 3.8k to 4k depending on port work and your exhaust setup, and of course the condition of the turbo.

well the car is black so it's gonna be hard to tell if there is any smoke...but ill look..just took it out for a ride and hooked the data logger up to see if my WB and the logger were matching. the logger was reading slightly different i didn't get the chance to full boost it to see what my AFR's were under boost. but i did notice that today when i drove it and i hit about 2500 the drive train started to make a chattering noise, almost like the splines in the t-case or somewhere were slipping...whatever it was doesn't sound good at all.

 

[gofer]

If your logger shows a front o2 voltage of .98v-1v when your WB is at 10:1 then your going EXTREMELY rich. Does the car show any knock when its happening?

It sounds like you might have to fix some other problems first before you start troubleshooting your WOT issues.

 

[stratplayer24]

If your logger shows a front o2 voltage of .98v-1v when your WB is at 10:1 then your going EXTREMELY rich. Does the car show any knock when its happening?

It sounds like you might have to fix some other problems first before you start troubleshooting your WOT issues.

It showed one count of knock at one point..but it never showed up again. i got to go to work soon so when i take it to work ill try to see what my other problem is. hopefully i don't need a new t-case of something.

 

[ChiTownHussla]

+1 my tsi does this too....want help so I will +1

 

[h2rsturbo]

this sounds like fuel cut to me. i had the same issues, at the time i had similar mods then i got my ecu chipped and bye bye fuel cut..

 

[ExpresS]

Yeah that's odd. Fuel cut in certain gears. Has to be some type of engine management issue. My laser did that but the new owner claimed it was just a boost leak.

 

[ChiTownHussla]

my tsi does it in all gears around 4k rpm if i hold the throttle down all th way. my boost spikes around 15 psi though and I am all stock....what can it be?

 

[Voodoo262]

Yeah that's odd. Fuel cut in certain gears. Has to be some type of engine management issue. My laser did that but the new owner claimed it was just a boost leak.

Fuel cut in different gears is not uncommon because the load on the engine is higher in higher gears. Higher load typically means more airflow

 

[white92talontsi]

Definitely fuel cut. A hacked 1g maf will be overrun around 20 psi or so.
If you running rich use the safc to take some fuel out. This will also in turn help with the fuel cut issue as the safc will make the ecu "think" its seeing less airflow. This will in turn stop the fuel cut issue. You must keep an eye on knock though. When you pull fuel through the safc you are also adding timing. So just be safe. Get the a/f ratio close with the safc and watch for knock.

Sent from my PC36100 using Tapatalk

 

[ChiTownHussla]

Hey guys I see these safc on craigslist all the time for like 250 is that a good price

 

[1GRedRocket]

Hey guys I see these safc on craigslist all the time for like 250 is that a good price

check the classifieds. i usually seem them for around 120

 

[ChiTownHussla]

thats all I need to tune my tsi? where and how do I hook it up

 

[1GRedRocket]

umm, i have never personally installed one but im pretty sure you have to solder the on the SAFC to the corresponding wires(pins) on the ECU. just make sure you get an SAFC that includes the installation instructions

 

[sykko]

fuel cut in not actually not enought fuel its to much air (boost)

 

[ChiTownHussla]

You can i get the fuel cut off. I hate it. I canto race on the highway. Kirkland this

So fuel cut is when there is too much air being read by the maf?