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The mkiv Supra Owners Club

Turbos knackered?


supRo

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I have j spec 93 TT, 95K miles

 

I had a FMIC and blue hoses installed....problems then began.

 

Sympthoms:

It started off with 2nd turbo not kicking in from 4th gear onwards, but if you drop gear, accelerate, it kicks in. When both turbos are on, they pull strongly.

Now 1st and second gear sometimes don't get any boost or boost goes only to 0.5 bar. It's now better top end, both turbos come online more often, however there is now a 'judder' from the engine about 3100 rpm, 0.5 boost but not alway. It goes away after higher rpm. There is no blue smoke.

 

The TTC mod made it slightly better but still had problems

 

The obvious has been checked properly, twice. Hoses have been checked and in right places. Had the VSV valve thingies checked, actuator has been checked.

The Boost pressure tank was replaced, made the problem 85% better but now it's gone back to how it was with the juddering

 

Could it be the ceramic blades are damaged - Are the turbos the most likely culprit? Possible Turbo 1 is iify hence 2 doesn't want to play properly? I've been told reliably it can't be fuelling or spark plugs.

Gonna have it on a dyno to see whats happening and probably have the turbos apart....

 

Any ideas to help with the diagnosis or if someone else has had similar probs? I believe this is quite an unusual problem?

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I have been over 1.2 bar a few times as my restrictor ring is too big.

If it helps:

I've got Walbro pump

FSE fuel regulator,

HKS Iridium s40i sparkplugs(6 months old/9K miles)

Full de-cat

hks back box

apexi induction kit

Apexi AVCR boost controller (fitted after the problems)

Greddy VSPL FMIC

Always use optimax

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Actuator was checked - can the wastegate be checked without removing anything?

 

Forgot to mention there is some misfiring at higher revs. Since the boost controller was fitted (after the initial problems), some times I get power loss at top end 100mph+, almost like Fuel cut, not as violent, just for a split second. I do have a TRL FCD

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