No Boost on 2nd Turbo.....SOLVED ***NOT SOLVED******

As above, i have had boost issues with my second turbo and thought it would be a good idea to show you guys the fault which i found to help anyone else out who might have the same problem

A few weeks ago i took the Supra out to a ACE Cafe meet and had a play on the way up there and all was good. About half way through the day i took a friend out who loves Supra's and had another play and everything was behaving. On the way home i gave it one last blip and noticed that the second turbo was not kicking in at all..So i pulled over, had a quick look but saw nothing that was causing a problem.. So before i set of home again i turned off the car, waiting a few minutes hoping it would sort it self out, started her back up and had another go

Still no second Turbo

Now i knew the turbo was fine as it was still driving ok and no smoke was coming out of the back. I was 99% sure it was a split hose as i have had this problem before on other cars and it felt them same symptoms so i was not too worried.

When i got home, i had another good look round all the hoses and could not find anything, i looked at all the main turbo hoses through to the throttle body and found nothing, Now this was bugging me as i wanted to put her away for the winter but not with a boost problem..So in the garage it went and it was time to try and find out through friends and the club what it could be.

While searching the forum i also had a chat with John (Hodge) and he said its most likely a vacuum leak to the VSV, so with this in mind i stumbled this thread done by Ian C

http://www.mkivsupra.net/vbb/showthread.php?35926-The-sequential-system&highlight=boost+problem

While reading and learning about the sequential system, i found the symptoms what i was having under the WHEN THINGS GO WRONG section

My car 1st turbo was spinning up to 0.5 then dropping when the second turbo should of been kicking in to 0.3 /0.2 which lead it to a problem on the VSV, So after work i opened the garage and thought i would have a good look round the VSV and when i moved one of the hoses i heard a hissss then hey presto

THE SPLIT

Now i have not repaired it yet but im 100% sure this is the problem, will confirm it when i get some hose

So big thanks to Hodge for leading me in the right direction and Ian C for doing a GREAT thread

The End

Your most welcome Michael, glad to help out mate.

Always nice to see one of my favourite supras working properly again

Need to swap a nice little purple hose for a shiny fan shroud ?

Your most welcome Michael, glad to help out mate.

Cheers buddy

Always nice to see one of my favourite supras working properly again

 

 

Need to swap a nice little purple hose for a shiny fan shroud ?

lol that shroud will be coming to you all in good time Sam when i get my elec fan kit lol

Thanks for posting up with pictures

Well i have my Supra back on the road and sorted the split hose...as above... which i thought was the issue but it has not solved the problem

So following this link

http://www.mkivsupra.net/vbb/showthr...=boost+problem

I have checked all over the place and cant seem to see another split hose

So my only conclusion is that i have a fault IACV valve. It has not been a intermittent problem, I had a play one day then turned it off for an hour then got back in and since then no second turbo

So my Qst is has anyone had any problem with these ?

Found another split...

All back to together but still no luck

The hunt goes on... Does anyone think the ecu needs to be reset after ??

Have you tried going TTC mode with the turbos to see that there is no problem with the turbo itself? otherwise i suggest that you take the car and let it make some boost, stop and pull off the hose that goes to the IACV VSV if you hear air leaving then you know that your pressure tank is okay.

TTC is a simple way to rule out any problem with the sequential system. if your car is topping 10ish PSI then it points towards either IACV or EGCV. as both of em will take out 1 turbo.

When connected to TTC and put to boost you should hear alot more noise from the exhaust=EGCV is fully open, and you should not get any boost down low but after 3800rpm you should start seeing some boost.

That will be my last resort, I will try the IACV valve first then if that does not solve it I will go TTC mode...

i have exactly the same. this thread has really helped!!

put peddle to floor

lol loads of noise, no boost!!

Right I have just went TTC mode and still no boost........SO

Intercooler hose that I maybe have missed ??????

i have exactly the same. this thread has really helped!!

Have you solved yours then ?

Wish I mine was solved lol

not yet but i have the exact same symptoms and this thread has given me a good start.

did yours happen gradually or all of a sudden?

i could hit full boost yesterday then Ll of a sudden lost turbo 2 next time i kicked down a gear.

I had a good play for ten minutes taken a friend out on a meet at ACE cafe, parked up, talking for a but then on the way home no boost in second turbo, has not come back since

sounds the same went out for a blast stopped for fuel, pulled out onto slip road and kicked the auto down and all of a sudden important not roaring forwards as expected.

This is a thread i will be watching closely..... My supra also lost the 2nd turbo boost lately

No smoke from the rear, oil level is fine (been checking it over a long period of time) and no boost from 3800rpm onward.

So far i have swapped 99% of the hoses on the turbo side (as they are all 17 years old now) and i swapped two from the pressure tank today (as one was deffo leaking...) however i havent taken it for a spin since, but i dout it was a leaky hose from the pressure tank.........?

Failing this i think it is likely to be the valve that opens the flow to turbo two.....

tried TTC yet? Im going to do this first and see where we go from there.

Maybe a long shot, but have you upgraded your fuel pump lately? If you have, try removing and refitting the pump.

tried TTC yet? Im going to do this first and see where we go from there.

I havent, but i might now i have just read it above

Maybe a long shot, but have you upgraded your fuel pump lately? If you have, try removing and refitting the pump.

Nope, pump is standard as it came from previous owner, but i might take a look

This is a thread i will be watching closely..... My supra also lost the 2nd turbo boost lately

 

No smoke from the rear, oil level is fine (been checking it over a long period of time) and no boost from 3800rpm onward.

 

 

So far i have swapped 99% of the hoses on the turbo side (as they are all 17 years old now) and i swapped two from the pressure tank today (as one was deffo leaking...) however i havent taken it for a spin since, but i dout it was a leaky hose from the pressure tank.........?

 

Failing this i think it is likely to be the valve that opens the flow to turbo two.....

That's what I thought was wrong with mine so as someone suggested I tried the TTC Mod which in my understanding bypass the sensors...

Here is what I have done ... If I have done it wrong please could someone tell me lol

I bypassed the IACV here

Took the other end of this pipe off the valve below and moved it to here

As far as I know this is all you do to do the TTC modd

Though for me at has NOT made a difference.

if we can't solve it might be worth a mini meet to check the cars, another set of eyes and all that.

i only have a meter of hose so going to replace as much as i can and go from there.

Going to try TTC first though.

The TTC first picture is correct yes, im unsure on the last two, however there is a TTC "how to" thread on here.

I swapped loads of hosing and its no better, altho the first turbo holds a little more pressure (good to freshen up the old hoses tbh)

But still no 2nd turbo

Can do, I'm based in Molesey and have all tools etc

Getting peed off about it now, just gone out side again to have a look at the Intercooler pipes but can't have a good look without taken the bumper off...though I can't feel a split