well i just picked up a 89 supra turbo 5speed and on the way home ever time it hit boost like 3 pounds going off the stock guage it would bog down? also i can smell gas when i let off
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boost cut
- Thread starter supratoyota18
- Start date
87mgte;988924 said:
That's a new one...where do you guys come up with this stuff?
supratoyota18;988899 said:
Sounds like a boost leak in your IC piping.
By "going off" I think the OP means he's reading 3 psi on the stock gage. At least that's my interpretation. Based on the display of illiteracy routinely seen here I could be wrong though...
yes thats what the stock guages reads. its bone stock so i guess ill have to do a boost leak test.
Down but not out;989540 said:What me fail engrish thats umpossible
what im dyslexic? and im like a step up from special ed class because im not good at spelling, reading or writing :icon_sad:
lol found a big split on the coupler coming off the turbo right after the clamp. so how should i got about fixing it should i get two 45s and a peice of pipe or ?
87mgte;988924 said:
This is what I had a problem with slick.
87mgte;990009 said:
Where did you get "11.4-13.7 psi" for fuel cut?
You are demonstrating a basic misunderstanding of how/what fuel cut is based on.
jdub;990026 said:This is what I had a problem with slick.
Where did you get "11.4-13.7 psi" for fuel cut?
You are demonstrating a basic misunderstanding of how/what fuel cut is based on.
Well my stock gauge only goes to 8, so 3 lbs above the stock gauge, which I interpreted "off the gauge" as, would be around 11-12 lbs, would it not? I won't lie to you, I don't really know what specifically causes fuel cut. I've just read around here what multiple somewhat-knowledgeable people have posted about it and that it usually happens (multiple answers) above 12 psi or around there. Could you provide a (Supra specific, of course) link to where I can read up and not seem MR?
jetjock;988977 said:
You could also interpret per above (as did I)...hence the recommendation to check for boost leaks.
To *really* figure out how the TCCS (ECU) works, you need one of these:
This comes in handy too:
(Thanks JJ !)
The AFM on a turbo is a Karmen Vortex type. The honeycomb generates vortices that cause a thin foil mirror to vibrate...a photocoupler "reads" these vibrations and transmits a pulsed signal to the ECU. Look at it in terms of air volume being pulled past the AFM and into the intake system. This is how the ECU determines when turbo pressure is too high producing what everyone calls "fuel cut"...when air volume exceeds a set amount, fuel is cut off at the injectors by the ECU. This volume is also subject to an intake air temp correction. Base temp is 20 deg C...injection is controlled by +/- 20% on a Karmen Vortex type to account for air density differences in the intake charge. Fuel cut is subject to this correction...that is why you will see fuel cut occur at lower boost levels on a cold day.
So to say fuel cut is xx psi to xx psi is incorrect...the real answer is it depends. But, you can always say it is based on air volume passing the AFM. That is why I had a problem with what you said...you can't put a precise number on it. It *usually does* occur in the 11-14 psi range, but I've seen it happen at 9 psi on a cold day. And, with a boost leak (like in this case) at 3-4 psi.
You getting these numbers off SOGI, I can understand your point (they are wrong though)...but, to tell me that's what Toyota says I have a problem with
jdub;990091 said:You could also interpret per above (as did I)...hence the recommendation to check for boost leaks.
To *really* figure out how the TCCS (ECU) works, you need one of these:
This comes in handy too:
(Thanks JJ !)
The AFM on a turbo is a Karmen Vortex type. The honeycomb generates vortices that cause a thin foil mirror to vibrate...a photocoupler "reads" these vibrations and transmits a pulsed signal to the ECU. Look at it in terms of air volume being pulled past the AFM and into the intake system. This is how the ECU determines when turbo pressure is too high producing what everyone calls "fuel cut"...when air volume exceeds a set amount, fuel is cut off at the injectors by the ECU. This volume is also subject to an intake air temp correction. Base temp is 20 deg C...injection is controlled by +/- 20% on a Karmen Vortex type to account for air density differences in the intake charge. Fuel cut is subject to this correction...that is why you will see fuel cut occur at lower boost levels on a cold day.
So to say fuel cut is xx psi to xx psi is incorrect...the real answer is it depends. But, you can always say it is based on air volume passing the AFM. That is why I had a problem with what you said...you can't put a precise number on it. It *usually does* occur in the 11-14 psi range, but I've seen it happen at 9 psi on a cold day. And, with a boost leak (like in this case) at 3-4 psi.
You getting these numbers off SOGI, I can understand your point (they are wrong though)...but, to tell me that's what Toyota says I have a problem with
Thanks for the info, jdub. Sorry for seeming ignorant, I wasn't tryin to be. I'll search harder or PM you to bug you about it next time.
87mgte;988924 said:
Oh man? wow, saying that the gauge is not accurate, I have a autometer and they run equal until you go over the stock psi on the gauge which can't be read anymore, where:nono: are you coming up with these things....
Your car can handle 12 Psi on the stock turbo, I think before I got a new turbo I tried to see what I could get and I got 15 psi on a stock ct-26 and I got it to 19 Psi but that was with fuel cut.:icon_surp87mgte;990049 said: