so that's pretty much what it does like i said in the title. im running a stock turbo @ 12psi, stock injectors, fuel pressure regulator set at ~20, and a lexus afm. When i accel. hard in first and second it doesnt chug, but sometimes in 3rd under full load and usually in 4th and 5th it chugs almost like it's getting too much fuel...or maybe not enough? the exhaust does "pop" quite frequently also between shifts, that may have something to do with it. i'm new to the supra and kind of new to boost so thank you for any help. ooh, also, i do have a wideband o2 so if there are numbers i can look @ to better help anyone understand what the problem might be, let me know. Thanks!
chugging under heavy throttle in higher gears
- Thread starter old skool
- Start date
old skool;1309194 said:
Up the fuel PSI, add 550's or remove the afm. what does the WBo2 say at wot?? I can only imagine super LEAN
:nono:old skool;1309194 said:
remove the lexus untell you get 550's and reinstall OEM FPR since your not running upgraded injectors or pump. Problem fixed :icon_bigg
You'll be lucky if you haven't messed something up by running that lean. Hopefully you haven't. What AFR's is it showing at WOT?
As stated above, I would definately install the stock AFM until you can get you some 550's. The Lexus AFM is 25% larger but you're still on stock injectors. That adds up to KABOOOOM!
As stated above, I would definately install the stock AFM until you can get you some 550's. The Lexus AFM is 25% larger but you're still on stock injectors. That adds up to KABOOOOM!
If you're venting to atmosphere, that will explain a lot of the popping.
And i third the suggestion of getting that lexus afm out of there till you get 550's!
And i third the suggestion of getting that lexus afm out of there till you get 550's!
definately noted on the stock afm. my WBo2 @ WOT = low 10s - high 9s (i have some learnin' ahead of me). i dont get on it very often cuz i really don't know whats causing the prob. some ppl that i have shown directly seem to say it's running (and smells) pretty rich by looking @ the Wo2, which i thought myself, so its interesting seeing that you guys are saying im lean. im for sure going to look into the stock afm & the 550s.
grim, what would you suggest i up the pressure to. it's bout 20 @ idle...from what i hear it shouldnt go above 40 @ WOT.
EDIT: im also going to check the plugs n make sure the gap is correct and that they arent fouled. what would you guys suggest as a proper gap?
grim, what would you suggest i up the pressure to. it's bout 20 @ idle...from what i hear it shouldnt go above 40 @ WOT.
EDIT: im also going to check the plugs n make sure the gap is correct and that they arent fouled. what would you guys suggest as a proper gap?
take the vacuum hose off the regulator and set it to ~35 psi at idle then attach the vacuum again
that seems a bit rich, but don't know if that would cause a "chugging"
I would set the fuel pressure to spec, and check for any codes...to start anyways.
I would set the fuel pressure to spec, and check for any codes...to start anyways.
CajunKenny;1309851 said:
It's actually 0.031"
However, for above stock boost you want to bring it down a bit...0.027" works well for me.
BTW - My FP is 27psi vac on at idle with the Lex/550 combo. If you're using 440's with a Lex, you want that up to at least 30-32psi (vac on). If you must run 440's, I highly suggest you get a wideband O2 to make sure you do not go lean...that will ruin your whole day. Sourcing a set of 550 injectors is the way to go with a Lex AFM.
That is going to depend on the condition of your 440's...I would start at 32 psi to see if it eliminates the problem. Going lean is another matter...you need a wideband. Any FP psi numbers is pure speculation. I would avoid going into the high RPMs until:
1) You get some 550 injectors
2) You install a wide band
That is if you like this motor
1) You get some 550 injectors
2) You install a wide band
That is if you like this motor
im @ 50% success rate...i do have a wideband installed currently...it hovers from 14.39 - 14.75 @ idle but on average is between 14.40 - 14.55 or so.
EDIT: just took another look @ the FPR to make sure i gave you all the correct #, i was off. it sits @ 48!
EDIT: just took another look @ the FPR to make sure i gave you all the correct #, i was off. it sits @ 48!
Last edited:
Wait...you can't see your wideband while you are driving? What's up with that?
A 14.4-15.0 AFR at idle is good. I need to know what AFR does under accel.
48 psi (with vac on) is a bit on the high side...you're "chugging" could be from a over rich condition.
A 14.4-15.0 AFR at idle is good. I need to know what AFR does under accel.
48 psi (with vac on) is a bit on the high side...you're "chugging" could be from a over rich condition.
hahaha...oh man, i'm sorry...total misunderstanding. i can totally see the WB while driving. under WOT @ full boost it dipped into the high 9s...9.9X area...that makes me feel a bit uncomfortable so i don't push it. the highest i've seen it read is 16.00 but that's only during decel.
Ok...that's better. Why is a 9.9 AFR making you uncomfortable? That AFR is very rich under accel...11.0-11.5 is a better target. Drop your FP as suggested...start with 32-34 psi and pay attention to AFR. The popping you hear in your muffler is unburned gas lighting off.
16 AFR under decel is normal.
16 AFR under decel is normal.
awesome! thanks a lot...i really dont know a lot about this stuff (obviously), so i'm gonna try that out and let you know. That should be fine till i get some 550s, yes? I'm gonna have a look around for the stock AFM as well just to be more on the safe side.