Help with car boost issue.

honda boi

Need help with a boost issue that's being plaguing me for months.
Car is 04 cmax 1.6tdci.
What happens:
In mostly 2nd or 3rd gear,when I accelerate at 2k turbo boost kicks in for about a second then just drops dead ,for about a second or 2 the car doesn't really accelerate then the turbo kicks back in and boosts.
It seems a lot more noticeable in lower gears rather then 4th or 5th.
This doesn't happen all the time,intermittently.
It seems to be getting worse lately (or its just annoying me a lot more).
What I've done.
Egr is blanked(not programmed out)
Turbo only has about 27,000 miles on it
New maf sensor
New map sensor
4 new glow plugs(3 were dead out of 4)
And a New turbo pressure converter just 2 days ago.

Codes that were on the car before pressure converter was fitted
P138b( I suspect its the glow plug relay as changing glow plugs didn't solve the issue although my limited knowledge is telling me the glow plug issue wouldn't affect the boost of the car)

P0238 (this to do with the turbo,why I fitted the pressure converter )

I scanned with forscan ,not a cheap bluetooth obd so these the only codes on the car.
Anyone any ideas?
Friend said could be an ecu issue which if it is I'll scrap the thing as that'll most likely cost a lot and I've spend a fortune already on this thing.
Edit: I've checked around and can't see any cracks or leaks(tho I could of missed something) and if there was a crack or leak in any of the pipes surely the issue would he a constant thing?

enumbers

You need to look at your boost pressures under load to see what is happening. Then you can work out if you have a boost control issue or boost pressure sensor issue (wiring etc.)

honda boi

enumbers wrote: »

You need to look at your boost pressures under load to see what is happening. Then you can work out if you have a boost control issue or boost pressure sensor issue (wiring etc.)

How would I monitor the boost pressure .
Would the torque android app be good to use?
What kind of readings am I looking for?
I know that the boost psi drops when it happens.

enumbers

honda boi wrote: »

How would I monitor the boost pressure .
Would the torque android app be good to use?
What kind of readings am I looking for?
I know that the boost psi drops when it happens.

I'm not sure what readings you will get with that system, any decent diagnostic equipment will let to see the boost pressure, it will measure in bar or kpa normally , you would expect to see around 2.3 bar displayed under hard load

honda boi

enumbers wrote: »

I'm not sure what readings you will get with that system, any decent diagnostic equipment will let to see the boost pressure, it will measure in bar or kpa normally , you would expect to see around 2.3 bar displayed under hard load

Thanks enumbers.
I've forscan on the laptop but my decade old laptop needs to be plugged in constantly as the battery is buggered ,I'll have to order one of those car inverters to use it.
If memory serves me correct,using the torque app before boost went up to 20 psi,looking online seems to be the figure it should be.?

mullingar

Check the dpf differential pressure under max acceleration. Should be something like 10-20kpa max

honda boi

mullingar wrote: »

Check the dpf differential pressure under max acceleration. Should be something like 10-20kpa max

Hi mullingar.
No dpf on my car

dieselbug

When the turbo was replaced was it a complete unit with the actuator included. Can you check the movement of the actuator using the forescan. check if is moving free and smooth or just remove the linkage and move it by hand.

mullingar

The control of the Turbo is vacuum based via a small actuator and controlled by a solenoid control valve. @op, see if you can move this up/down 1cm

I had a strange intermittent fault with a 110hp version, only found when I T'd in a vacuum gauge into the Turbo actuator and went for a drive. When the engine power was down, the vacuum gauge was jumping all over the place, so fast the needle was just a blur. Turned out to be a faulty cold trolley valve.

honda boi

Well lads
Only had a chance to have a quick look at the actuator today.
It moves up and down a tiny bit not much when revving it.
When I shut the engine off after a few seconds the actuator moves a bit more back to its original position ( moves about 1-2 cm)
Couldn't get my fingers in to try move it by hand,didn't have time to take apart and get to it.
I'll make a video of how it moves when idling and been revved as I'm unsure on how its actually meant to move tomorrow

mullingar

The ecu will only move it fully under full engine load, pointless when stationary.

Did you just replace the Turbo cartridge? Or the complete turbo? There are little vanes that controls the air volume through the Turbo and these are known to stick if carboned up and are separate to the cartridge

honda boi

mullingar wrote: »

The ecu will only move it fully under full engine load, pointless when stationary.

Did you just replace the Turbo cartridge? Or the complete turbo? There are little vanes that controls the air volume through the Turbo and these are known to stick if carboned up and are separate to the cartridge

Honestly couldn't tell you what was replaced , all I was told was to get a reconditioned turbo and the mechanic got that. Unsure if that's just cartridge or complete .
Anyway to check the little vanes inside without dismantling the turbo? Or anything I can spray in to clear it?
I've checked the fins/ turbine on the air flow side and its perfect. No play and spins freely.
I wouldn't even have any kind of camera to put under the bonnet to check if the actuator is moving freely while driving.

PukkaStukka

If you're still getting P0238 then as others have suggested, the live data needs to be monitored closely to determine at what point the drop out is happening. Are you sure there are no underboost fault codes either? And you say the MAF sensor was replaced? This is the one on the main air intake assembly just above the alternator?

One thing that does give problems on them is the Vacuum pipe from pressure converter to the turbo's variable vane actuator. Use a vacuum tester to confirm it can hold the vacuum consistently i.e. vac it up and leave it for a few minutes to confirm it can hold it without dropping.

What might be happening is that when RPM increases and the pressure converter opens to increase the vac on the turbo, the vacuum pipe may have a small split or hole that the increased vacuum causes to open further, thereby loosing all the vac and releasing the vanes on turbo. That will cause the sensation of loosing power like you describe.

PukkaStukka

Just seen in the OP that the EGR is blanked off. This will not help your problem because there is no wastegate on those engines and boost pressure is controlled by a combination of EGR and vane control (assuming this is the 110bhp). Are there more fault codes than just P0238? If so, please list them!

honda boi

PukkaStukka wrote: »

If you're still getting P0238 then as others have suggested, the live data needs to be monitored closely to determine at what point the drop out is happening. Are you sure there are no underboost fault codes either? And you say the MAF sensor was replaced? This is the one on the main air intake assembly just above the alternator?

One thing that does give problems on them is the Vacuum pipe from pressure converter to the turbo's variable vane actuator. Use a vacuum tester to confirm it can hold the vacuum consistently i.e. vac it up and leave it for a few minutes to confirm it can hold it without dropping.

What might be happening is that when RPM increases and the pressure converter opens to increase the vac on the turbo, the vacuum pipe may have a small split or hole that the increased vacuum causes to open further, thereby loosing all the vac and releasing the vanes on turbo. That will cause the sensation of loosing power like you describe.

Sorry for the late reply.
Here's a pic of the codes I got just now.

The egr fault comes up every now and again due to it being blanked off.
I changed the glow plug relay yesterday evening and the glow plug fault is still coming up so I'm guessing its a wiring issue/short somewhere in the harness.
I'll check all the pipes by the pressure converter when the weather gets better.
No chance me going out now in the rain and 100kmh winds
The maf is the one that's beside the air filter.
The one your referring to is the map or boost control( that's what I've been told it was anyway ) ,that was changed as well.
Egr has been blanked for a long time and the car was running good at one stage after it was done. So I wouldn't think it would all of a sudden effect it now.
Edit : cant do live data with laptop is battery is dead and needs to be plugged in constantly.
Gonna either get another battery or an inverter for the car

PukkaStukka

Typo, yes - meant MAP instead of MAP...my bad :rolleyes:

Anyway, I'd check the vac pipes to ensure they're ok, and failing that, you're looking at more involved diagnostics. To be honest, my feeling is the EGR fault will have to be sorted as part of this to get that car right. The P0238 might or might not be part of that.