Boosting issue

[torrentialmetro]

Hey everyone, first post here.
I’m Matt, from Brisbane Australia. Currently running a Motec M400 with SLM and USB data connection.
I’ll warn you now, I’m a complete novice and just trying to isolate the issue with my car before taking it in for an updated tune.
Recently I’ve removed the catalytic converter from my car and re-did my turbo drain due to a small leak. I replaced Turbo and BOV Vac lines whilst I was in there.

Now, since doing the work I’m having issues getting boost to generate with my setup. I’m hoping someone might be able to assist me in the problem as I’m stumped on it. I also removed a portion of intercooler piping and re-plumbed. I cannot hear any boost leak nor can I see any visible issues with the vac lines.

Please find attached Diagram of my current setup.
Turbo is a TD05 Hybrid with a GT2871 centre
Boost solenoid is a Mitsubishi 2 wire 2 port setup. – Part Number

Previous workshop/tuner configured all the setup so I’m not even sure if it’s an ideal setup, however I assume it’s just a controlled bleed valve.

A few things I’ve been told thus far and I’m hoping to save time by posting these.
1. Duty cycle can be affected by removal of the cat and may be a contributing factor.
2. I’ve done something wrong. (All lines were reconnected in order and same hose lengths)
3. I’m stupid.

Based on the above information, is there any suggestions as to what I can look for on my ECU / set up?
I’ve already stripped and re-done the ENTIRE vac line setup and intercooler hoses twice now with the same result.
The only other bits of information I can supply is that the car produces 10PSI until 7.5K RPM where it begins to produce around 18 before hitting RPM cut at 8.5K. This is what has me stumped.
Also, the Boost Aim and Boost Aim Error appear to be the same, which leads me to believe that the solenoid could be dodgy, but again, I don’t know enough.

I can supply data log if required.
Thanks for your help

Cheers

[alcindorr]

Hi.. The log it will help it a lot! Please post it.
To have sure it's not a mechanical issue UNPLUG the waste gate hose.. you should get FULL! boost real quick, then you will have sure it's something on the solenoid or plumbing... if your solenoid go to a 100% duty you should have a decent amount of boost unless, it's not working or the hose going to the solenoid it's to small or the bleeding side it's too small.
AL

[stevieturbo]

You dont give anywhere near enough information.

Firstly, how was it boosting before you made these changes ? And after the changes, are you wanting boost to be the same ? What is actually different ?
And after the changes, has the ecu been remapped, or are you just expecting everything to be the same ?

And you say everything is plumbed as it was before.....often people think this. But are you 100% sure ?

Without seeing your setup and what you've done, it's so difficult to make a diagnosis based on the info you supply.

Certainly the diagram you have drawn looks like a feasible setup that should allow you to control the boost from the ecu. But that doesnt mean your existing mapping is suitable after the changes you have made, which could explain the changes

[torrentialmetro]

Hey guys.

Thanks for the responses, I wasn't sure how much info you guys/girls may need so I thought I'd keep it short and sweet(ish) with the first post.

ECU has not been retuned since the de-cat was done on the vehicle and I ensured all vac lines went back as they were, even referenced off some existing photos I had on my phone.

Factory turbo runs a 10PSI Actuator, currently it's feeding stock boost into the car (10PSI) where-as it was putting ~21PSI into the car as per the solenoid control. It's not reaching maximum boost or even getting remotely close until you hit around 7.5/8k rpm. I'm going to purchase some more vac lines and re-plumb it a third time to be safe but currently I can't see anything else.
Failing that, is there a way to diagnose a solenoid and check it's working?

I will free-spool the turbo and see how it goes though I wont take it about 15-20PSI at absolute max. Car doesn't generate 20PSI until 4.7k rpm anyway.

stevieturbo; I do hope this is what you required. I wasn't expecting any changes from a simple de-cat though it did show minimal signs of carbon deposits all through it, so it should be flowing a little better. That said it was running a tad rich prior so I'm assuming a shift in flow wouldn't have leaned the car out too much. I've got a Lambda sensor in the car so it's easy to track my o2 output in the system as we are.

Again, thanks for the help guys, this is doing my head in!

[Holmz]

Hey guys.

Thanks for the responses...
...

If you block the wastegate bypass does it build boost?

I assume that the CAT was after the turbo?

[Chris Wilson]

If anything cat removal will see boost try to rise, as they can restrict the exhaust. Have you read the Webinars on boost control on the main Motec site? They are excellent and will give you a good grasp as to how the setup should work, how to log it, and what may be wrong.

[torrentialmetro]

Holmz, I let it free-spool with open vac lines and it didn't generate passed 15psi so I'm going to do another leak test on the whole system and replace some intercooler joiners.
I've read the webinar yes though most of it didn't make too much sense to me, I guess it's one of those things I will pick up in time.

I'll turn on boost logging, and download a file to upload.

Cheers

[stevieturbo]

So to clarify

Before, standard car ( Or Motec car ? ) was making 21psi most of the rpm range ?

After de-cat and plumbing changes, it now only makes 10psi until high rpm ?

You must have changed some plumbing, or blocked the exit bleed on the solenoid. A faulty or dirty solenoid is also possible.
Or have you tampered with the wastegate actuator itself at all ? Jammed open, bent, damaged ?

However once you do get the solenoid working, you WILL need a remap otherwise you risk seeing much higher boost than before. Ive no idea what safety measures are programmed into your existing ecu, so tread very carefully.

[stevieturbo]

Holmz, I let it free-spool with open vac lines and it didn't generate passed 15psi

Again, be very specific about what you are saying

You removed or clamped the pipes from compressor cover to the wastegate actuator, and still see only 15psi boost ?

if so, then your wastegate actuator/flap must be partially or held open.