Turbo Boost Problem

[fzr400]

Hi Guys,

I ran out of petrol the other day, (to be honest I often do), the car jerked as it always does,and then I had limited boost, i have a 96 turbo with a Blitz boost controller, I checked for fault codes, nothing, so I reset the ECU anyway, still no change, so I reset the boost controller, still the same, I will be checking tomorrow for leaks in the pipes etc, but not convinced I'll find anything, has anyone had this problem they could help me with?

ok checked all the turbo pressure pipes all seem ok, could i be looking at a shagged turbo, missing fins etc, or the wastgate stuck open? if i hold it hard in say 3rd 4th, I can get it up to 11-12, but it used to run to 16-17 then capped at 19 by the controller

any ideas?

cheers

Jon

[boundsw]

Well it is boosting, so id say the turbo is ok, hopefully ! does it seam to spool properly ?

Waste gate could be stuck open / burnt out, sometimes if they dont close properly for some reason they can burn out aroud the sides, and so never really close and cause constant lose of boost ! (does it boost / spool as quick as normal ?)

try disconnecting the BC, and run a standard setup, hose from actuator to turbo, run stcok boost.

does it run stcok or is the boost all over the place ? (with out the controller that might give a clearer picture as the controller is trying to 'trick' the turbo into working harder ?!

do you have A BOV? is that closing properly? (revt eh var hard on your drive and see what the BOV does, does it close / open ?

i dont think running out of petrol would cause boost problem, ubless you have blcoked an injector with crap from the tank, causing bad fireing and so less boosdt, does the genral engine sound ok ?

[fzr400]

Well it is boosting, so id say the turbo is ok, hopefully ! does it seam to spool properly ?

Waste gate could be stuck open / burnt out, sometimes if they dont close properly for some reason they can burn out aroud the sides, and so never really close and cause constant lose of boost ! (does it boost / spool as quick as normal ?)

try disconnecting the BC, and run a standard setup, hose from actuator to turbo, run stcok boost.

does it run stcok or is the boost all over the place ? (with out the controller that might give a clearer picture as the controller is trying to 'trick' the turbo into working harder ?!

do you have A BOV? is that closing properly? (revt eh var hard on your drive and see what the BOV does, does it close / open ?

i dont think running out of petrol would cause boost problem, ubless you have blcoked an injector with crap from the tank, causing bad fireing and so less boosdt, does the genral engine sound ok ?

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[fzr400]

Thanks for your reply, the things I notice are:

if im in say third put my foot down at 3000rpm, ok ish to about 2psi then turbo is slow boosting up after this, then it slowly creeps to about 6 @standard boost and setting the controller to very high I can get it to creep to 11ish, but slowly...

the engine runs fine not misfire or buccking under boost at all, it is 100%

I agree, running out of petrol would have nothing to do with it, but seem to happen around then, I was thinking the jult of the engine may have dammage a hose/intercooler, but I have checked, and found nothing.

I did run the boost controller off and fitted a bleeder T, still the same, then I opened the circuit to atmosphere, and my guess it would boost unlimited, but it didnt.

the turbo doesnt seem to be sounding different.

I checked the blow of valve, it is an after market Blitz one, which I cleaned and refitted, and when you rev it there doesnt appear to be any leakage, and as i let off the throttle, it snaps open

If i take the pipe off the turbo, (turbo outlet) and put my hand over it, and rev it quite hard, will this blow my hand off or will the air ecape/not build up pressure?

thanks again Jon

[boundsw]

I doubt u wilk be able to run the car with the pressure side of the turbo pipe off ! I doubt it will start !

do you have enough oil in the engine ?

if the turbo had no oil feed, then you could have damaged the turbo, as it seams to be strugling to boost, might have knakered the bearings !

check by taking off the inlet, you can feel the blades ! are they free to rotate ! or is there any play horizontal / vertical ? should just spin !

if you can, check the exhsut side, although this is more of a big job, but then you can see the waste gate, and the exhaust side blades !!

[fzr400]

I have run it with the pressure pipe off and can feel the pressure that the turbo gives off, but wasnt sure if this would blow me across the carpark, or you would feel a fair amount of pressure, there is pressure there you can hear it and feel it, but if i put my hand on it to block it, rev it up I can stop the pressure.

oil is fine, I have not checked the fins for dammage,

do you think I should be looking for another turbo and actuator, then swap over as ive come to a dead end, it just did it one day and has been there ever since, there was no warning /noises crunches etc

cheers

Jon

[boundsw]

Turbos are expensive and not really that easy to fit !

Do you know anyone else with a turbo you can compare it to

Check the fins, are they free moving, and check the ehaust side blades if you can be removing the downpipe...effort, but may show you the problem

[fzr400]

thanks, I will try this, i only have friends with other turbo cars not MR2's, but will look at the blades, and see what I can find.

thanks again for your help

Jon