CT20 turbo only boosting too 3-4psi (pics)

[HTH]

Hey guys,
recently bolted a ct20 turbo set up too my 2.8d lux.

Everything is working well except the turbo wont pass 4psi.

I have a boost controller and ive played with the actuator but nothing seems to make a difference. The actuator doesnt even seem to move to release pressure at high rpm so i thinking it might be set too a low boost internally??

is that even possible?

Another thing is the piping between the turbo/intake/airbox is all 3inch stainless tube. Is there a chance that the tube is too large and cant create enough pressure??

Here is a pic of my set up... all advice welcomed

[hulsty]

what are your EGTS? did you turn the fuel up? Not enough fuel/load and you wont get boost

[HTH]

I havnet taken the car for a big run yet because im worried about it running too much fuel. I havent adjusted the fuel yet but the car has been fitted with larger injectors and i think its already running too much (excessive black smoke).

Cheers, HTH

[stock 4runner]

i run an inline boost controler instead of one off to the side maybe crimp the line and see if you get more boost . and check your waste gate linkage is not ajusted to long and holding the gate open.

[callook]

How old is the turbo? Could have a crack around the wastegate port !
Have heard this is common on ct20's

[dogbreath_48]

Wind up the fuel and take it for a quick drive; you'll know if that was your problem before any extreme overfuelling can do any damage. I'll say it is the problem, n/a fuelling would only support 3-4 psi on my 2h

[Zookified]

I did mine about 2 years ago and it made 1psi boost. To fit the turbo to mine had to loosen the clamp on the compressor housing and rotate is so the outlet andgle suited my 2.8 for pipework. When doing this is fucked the wastegate actuator. If you rotated yours check this.

Now I just run the wastegate wired shut permanetly and it makes around 13psi under HIGH load and rpms with the fuel done on a dyno.

[bundy_pig]

hey mate i would try by passing or getting rid of the boost controller first as boost controllers especially cheap ones are known for causeing boost problems. if thats the case just replace it if its not the case i would check for any boost leaks, or u could have a sticky actuator that can also cause u lack of boost. as youve already said your engine is already running rich so i doubt it would be lack of fuel limiting your boost. what condition was the turbo like before u installed it ? where all the fins on the compressor wheel in good condition and did it have much shaft play?

[HTH]

THANKS HEAPS TOO EVERYONE FOR YOUR INPUT!!

1) The turbo is brand new, so should have any problems there.
2) I currently have it running without the boost controller and hasnt made a difference.
3) I have adjusted the waste gate actuator many times after having to spin the turbo to make it over the block, has not made any difference.

The only thing i havent tried that you guys have suggested is winding up the fuel but as far as i can tell its already running rich. Also before i put the turbo on it was in at the mechanic getting work done and they had trouble getting it too run because it was over fueling (they had to retard the timing just to get it too run) because of the larger injectors + the injector pump maybe off a 5L.

CAN I RULE OUT THE 3" PIPEING BEING TOO LARGE??

thanks again, HTH

[granborismo]

i wouldnt think the piping is too large.. That should not make a difference.

Question, have you actually taken it for a drive? as most ct20s wont boost more than 4- 5psi with no load.

where are you checking your boost from,(intake manifold?)

ditch the crappy boost controller and take it for a drive. In standard form without running more fuel you should get around 7psi.

hope that helps.

[hulsty]

how are you telling that its running rich?

get a EGT gauge and actually find out.

[HTH]

hey mate, YES i have taken it for a drive and at best at full load and foot flat at high rpm it is just shy of 5psi.

The boost guage runs off the waste gate actuator line (can be seen in first pic). Ive put it here before in mates cars and has always given an accurate reading.

I'm starting to wonder if i have a leak somewhere, but as far as i can tell its not leaking from anywhere. WHERES THE BEST PLACE TO START LOOKING?

cheers, HTH

[HTH]

I have an EGT guage. it hasnt gone over 400deg since ive been driving it but that has only been around the paddock mucking around.

The car is unrego'd and has a small oil leak out of the sump, also i only just got it running and dont wanna fuck anything so im being cautious.

im 90% sure its over fueling just on how much extra smoke is coming out of the exhaust, seems like over fueling too me.

I will take a video of it running today and post it here so if anyones got time to have a look and diagnos it for me that would be awesome.

Cheers, HTH

[hulsty]

Is the EGT pre or post turbo? are those numbers F or C ?

[HTH]

Its pre turbo. Im actually not sure if there F or C. they may actually be F because it sits on around 65 when its cold. Not sure how i can exactly tell.

thanks again.

[hulsty]

If its pre turbo and in F its under fueled. Somewhere around 1000F 1200F pre turbo is getting hot EGT wise.

[HTH]

But do you think it wouldnt pass 5psi ??

I'll see if i can figure out if its in F or C. Thank for your help.

[dogbreath_48]

But do you think it wouldnt pass 5psi ??

I'll see if i can figure out if its in F or C. Thank for your help.

Even if its degrees C 400 isn't exactly hot. 750• is hot. As mentioned a short run with even a grossly overfuelled motor is unlikely to do any damage.

[HTH]

OK time to give the fuel a quatre turn see how i go.

Hopefully have time to turn it up sarv and let you's no how i go.

thanks again people. HTH

[HTH]

While removing some of my turbo piping to get to the fuel screw i noticed a fair bit of oil in the one of the pipes and in the INTAKE. Doesnt seem good to me, heres a few pics..





stressed out too say the least..

[tweak'e]

they are a little notorious for blowing oil out of the breather. fit a catch can.

however in the pics it looks like you have left the standard breather hooked up. if so it will be pressurizing the crankcase and i would not be surprised if its not blowing oil past the seals because of that.

[HTH]

Just wound up the fuel and took it for a run.. NO difference.

YES i still have the standard breather hooked up. WHERE do i hook the catch can up too, the hole in the top of the intake?

Do i just block off the hole in the rocket cover?

Any chance ill be losing pressure out of this pipe? It hasnt been blown off yet but its basically just sitting there..

thank ppl.

[dogbreath_48]

The rocker cover breather has to be hooked up into the suction side of the intake. Block up the original intake breather fitting (which is now on th high pressure side of the intake). A catch san can be fitted between the rocker cover and the intake if blowby proves to be excessive.

[tuffer_2.4]

have you tried a differnt boost gauge? re the oil in the intake is the turbo breathing into the sump via the stock breather? if it is it will blow seals out.

[granborismo]

Just wound up the fuel and took it for a run.. NO difference.

YES i still have the standard breather hooked up. WHERE do i hook the catch can up too, the hole in the top of the intake?

Do i just block off the hole in the rocket cover?

Any chance ill be losing pressure out of this pipe? It hasnt been blown off yet but its basically just sitting there..

thank ppl.

you must disconnect the original breather going into the intake manifold, as what is happening is your boosting into your rocker cover!

next thing is to block the hole where that pipe connects to the intake manifold. Then you need to run a longer tube from the rocker

cover breather to BEFORE the turbo intake, eg: top of air box or something. OR into a catch can, then pre turbo..

give that a go..

[bundy_pig]

im a bit confused as to why fuel could be the problem, i dont know much about diesel engines but i know with petrol engines fuel mixtures dont effect the amount of boost the turbo generates. i would still consider changing the accuator. u dont have much pipping so i doubt you would have many chances of having a boost leak. what exhaust system are you running?? turbos need to breath that could restrict your boost if your running a standard NA exhaust.

[tweak'e]

its not fuel mixture.
if you don't burn fuel you don't have exhaust gas to push the turbo. think of it as a petrol that only has 1/2 throttle.

i wonder if the injection pump is a little low in pressure to push the new injectors. check the injection timing.

as far as wastegate goes you should be able to rev it and see if its opening or not. you can do the washer trick if the boost controller is suspect.

[HTH]

Thank heaps everyone!

The accuator is staying closed because ive got it set so i wont open until high boost but its just not creating it..

Right now exhaust system is just a 2.25inch dump pipe i knocked up too suit the stock exhaust. NO stock exhaust fitting at the time being.

So i need to block off the hole in the top of the INTAKE MANIFOLD and run a new hose from the rocker cover to a part of the intake that isnt pressurised, or into a catch can and then into a NON pressureised intake?
Could not having this set up properly be causing the boost problem?

I worried about the oil in the pipe coming directly from the turbo to the intake because the oil is coming threw the turbo, is this a problem??
The catch can wont save any of this oil?

I'll get video today of it running and post it up.

Thanks too everyone who's been helping out i really do appreciate it.

[tassiehunter]

Hows it go? It's not just a bad boost gauge by any chance? On the under/over fueling, we recently boost tested my fathers boat as it felt a bit lazy off the mark ,it had 15lb of boost on one engine, tickled the fuel up and we had it back to 30lb, off memory we only took it up about 1/4 of a turn, I would get a diesel service to time and set your pump, if it doesn't fix it they should have an idea of whats wrong

[granborismo]

So i need to block off the hole in the top of the INTAKE MANIFOLD and run a new hose from the rocker cover to a part of the intake that isnt pressurised, or into a catch can and then into a NON pressureised intake?
Could not having this set up properly be causing the boost problem?

yes you need to set itup like this. Think of it this way, turbo boost= pressure in your intake manifold, if it is venting into your rocker cover

this is a no no. this will be where you are loosing your boost, as well as blowing seals and all sorts of shizz.

I always take my boost reading from the hole in the intake manifold, that will let you know how much boost is actually running into your engine.