supra trouble!

[R6RY D]

Help needed, i have had misfire under very hard acceleration, just as it goes to change up. so its been on a computer and the flash codes it brought up were
34-turbo pressure malfuction
and
31-airflow meter/ vacuum sensor malfuction

Has anyone had theese faults, or heard off them, because i have spoke to a garage that seems to know their stuff, and they think its a wiring fault behind the dash ie a bit off a bastard and couple of hundered quids worth. And before i commit to that i just thought i should check around. Any help geartly appreiciated. Ta

[tuttle]

Best head over to mkIVsupra forum for in depth stuff.
More info needed here plz: standardish tubby/set up? How much boost are you running & does it appear to be spiking?

>> Edited by tuttle on Saturday 21st January 10:08

[MrFlibbles]

Assuming the Supra ECU codes are the same as the MR2 Turbo codes.

Error 34 is the common one that people get when the car overboosts and hits fuel cut. Over on the MR2OC even cars running standard boost have been hitting FC in the cold weather. It seems to affect the guys that have aftermarket exhausts, decats and downpipes. They seem to make the exhaust a little *too* efficient.

Dont know if that helps.

[r5gttgaz]

deffo sounds like boost cut always get it in my starlet gtt with the cold weather its not a soft cut either, also de catting as previously said makes the boost go mad because the back pressure on the exhaust turbine is relieved .

[R6RY D]

That sounds possible to me, mine has full "sumo" and decat, cold plugs, filter, its had the boost set to 15 psi max boost on a roalling road, and had a fuel cut, is it possible its a faulty fuel cut?

[MrFlibbles]

R6RY D said:

, is it possible its a faulty fuel cut?

Its possible I guess, but I would have thought an overboost would be more likely.

[R6RY D]

the boost is controlled by a manual screw type cap ,do you think its worth turning it down? although will this affect the fueling? it was set up on a rolling road.

[r5gttgaz]

Aha sounds like a bleed valve, reducing the boost will not affect fueling at all as the ecu will adjust accordingly, It is when you raise the boost outside the set ecu map then you get trouble and you start to run lean hence the fuel cut/boost cut coming on to restrict the damage ie no fuel going in means no boost created you back off the pedal until running in the set ecu conditions again, IMHO close the bleed valve right off or get rid of it and invest in an electronic boost controller they are much safer.

[R6RY D]

how much is one off thoose? does anyone here have one? were fits them?

[tuttle]

Strongly reccomend fitting an EBC over a bleed, gives you excellent control over your tubby(s) .Not hard to fit, setting up can take a bit of time, essentially, once its done that's it tho.

[R6RY D]

i think thats what i will go for, power engineering is were i had it set up, and more importantly they are less than 5 mins from my house!

[Turbo T]

Does the car have the cats in? If not the you will need a fuel cut defencer, or as others have mentioned, you will hit boost cut. Is the misfire hard or soft?

[tuttle]

Turbo T said:

Does the car have the cats in? If not the you will need a fuel cut defencer, or as others have mentioned, you will hit boost cut. Is the misfire hard or soft?

Is a misfire like this a fairly common prob with de-catted tubbies Turbo T? The GTST will periodically do this if I really stomp it from a standing start @ hi boost<than 0.96Bar A fuel cut defencer will just over-ride the OE cut limit, yes?

[R6RY D]

mine has the small front cat in, and the big one removed. When it mises it very hard it litterally like being flat out and switching the ignition on and off very quickly.

[R6RY D]

And it does have a fuel cut defencer fitted

[R6RY D]

And it does have a fuel cut defencer fitted

[Turbo T]

No the boost cut is very hard, and the warning triangle will come on.

What is the peak boost?

[R6RY D]

yeah thats it red triangle comes up, and its such a bang if you holding the gearstick you stuff itinto nuetral (mines auto), so what do you reckon then?

[Turbo T]

R6RY D said:

yeah thats it red triangle comes up, and its such a bang if you holding the gearstick you stuff itinto nuetral (mines auto), so what do you reckon then?

It does sound like boost cut, maybe the FCD is playing up. Its also not speed related is it?

[R6RY D]

Is there any way of checking my fcd? or should i get another one chucked on?