Lex afm fuel cut raised higher than normal

[claricae86]

well i have lex afm and 550,s upgraded 57trim ct26, boost controller mhg, @15-16psi, etc. ive searched and havent found any answers. my car is still hitting fuel cut failry soon sometime. i dont have a a proper boost guauge yet but it futs at about 3500 or 4000 rpms. ive heard you can raise the fuel cut even higher than what it is by turning a plug on the lex afm. i was wondering if anyone had more info on this or has done this, that fuel cut is just so damn annoying even with the lex afm.


sorry mods if this has been covered ive just searched and all i can find is raising stock afm fuel cut

 

[gixxer750]

Boost leak....

That is all

 

[MKIIINA]

yea man sounds like you might have a boost leak. i ran up to 18 psi on an sp61gt w/o fc for a while w/o issue even when things got cool here in tx (40s) check your pipes.

 

[dbsupra90]

if you drill out the cap over the internal screw you can back it out some. the more you back it out, the more lean the a/f and the higher the fuel cut. i would not advise this without the proper metering equipment.

and it does sound like you have a boost leak as others have said.

 

[claricae86]

i did have a minor boost leak. one of the pipes had a crack in it. threw on another one thanks to old motor, and its back to normal. boost till 4500 probably more but i dont take the supra past that anyway. thanks for the info guys

 

[gixxer750]

wow....you shift @ 4500? my car doesn't even start making power until there...

 

[claricae86]

yea that uprageded ct starts spooling at like 4500. once i put on some new fuel managment parts ill get a fcd and be going a little higher

 

[shaeff]

yea that uprageded ct starts spooling at like 4500. once i put on some new fuel managment parts ill get a fcd and be going a little higher

you DEFINATLY have a huge boost leak, or your turbo is clipped WAY too much...

4500rpm for a CT-26 to start spooling is entirely too late. check you piping/couplers.

-shaeff

 

[claricae86]

sorry that didnt come out like it was suppose to. it starts boosting at around 2400 rpm and is boosting fine all the way to 4500 when i shift. sorry bout that didnt catch it till now.

 

[teamfuel91]

The reason your hitting fuel cut is beacuse the factory ecu has a fuel cut set for 10psi, I had the same problem on my 91 turbo. The best way to bypass it completely is to buy and install the HKS fuel cut defencer. It is easy to install, and costs about $125. This will completely eliminate fuel cut. I am currently running 15psi no problem.

 

[teamfuel91]

On the boost leak subject, if you had a boost leak, you wouldn't be hitting fuel cut at all, either your car would be extremely sluggish or just fall on its face.

 

[Jspec7m88]

wow....you shift @ 4500? my car doesn't even start making power until there...

:rofl: Turbo Lag, FTMFW.

yea that uprageded ct starts spooling at like 4500. once i put on some new fuel managment parts ill get a fcd and be going a little higher

4500rpms, eh? Sorry if this is already being discussed (I didn't bother to look at page 2), but 4500rpms sounds off just a little bit.

When I had my .57 Trim, I started spooling about 2800rpms.
Hell, even my 60-1 began to spool at 3150rpms.

 

[antman]

It is easy to install, and costs about $125. .

i have one for a hundred if you want it, but you should be fine with the lexus.

 

[xarewhyayen]

i say you need to get some proper tuning. such as an actual boost gauge so you can see what youre really boosting. that and i really hope you have upgraded your fuel pump already. Try some type of air fuel tuning too such as a SAFC/wideband combo. If you keep pushing the limits youre gonna get burnt, especially if you throw in a FCD and boost even higher than your fuel system can handle.

 

[shaeff]

The reason your hitting fuel cut is beacuse the factory ecu has a fuel cut set for 10psi, I had the same problem on my 91 turbo. The best way to bypass it completely is to buy and install the HKS fuel cut defencer. It is easy to install, and costs about $125. This will completely eliminate fuel cut. I am currently running 15psi no problem.

you don't understand the concept of the lexus AFM then, do you. read up:
http://rob.carlile.home.mchsi.com/lexus/lexus1.htm

then make an educated post about fuel cut

i hit a 20+psi boost spike, and never hit fuel cut with the lexus AFM. HKS fuel cut defencers are crap as far as i'm concerned. it's a good way to blow your motor. fuel cut is actually your friend, believe it or not. work around it properly. if you don't have the gizmos and gadgets to monitor AFR's and EGT's, then don't get a FCD and slap it on there. you'll probably melt your pistons.

aside from that fact, if you're on the stock fuel system, running 15psi, withouth having the injectors cleaned, and a new high flow pump put in, you're asking for melted pistons. i ran 15psi for months on the lexus AFM, with no problems what-so-ever. i NEVER hit fuel cut.

On the boost leak subject, if you had a boost leak, you wouldn't be hitting fuel cut at all, either your car would be extremely sluggish or just fall on its face.

how do you figure? if there's a boost leak, more air is flowing past the karman vortex sensor in the AFM than the ECU knows is "safe". when that happens- fuel cut. you could be sluggish, fall on its face, or hit fuel cut. check the codes when that happens, if it's a good boost leak, you'll see the fuel cut code stored in the ECU.

-shaeff

 

[claricae86]

walbro has already been purchased as well as an safc2 and new gauges im not planning on turning up the boost anymoer than it is and i dont get on it everyday. i should be fine till i get the new fuel pump in and as far as the injectors there brand new rc550's. thanks for the info guys