[Mk2] [Turbo] boost problem @ 4k-4.5k rpm

[suprmanmr2]

Hi guys,

Gave my car in for a service and got it back yesterday fitting an Apexi GT Spec exhaust and a japspeed decat. The car also has an apexi induction kit and an avcr controller on it.

The car was working perfectly fine with boost starting and kicking in how its meant to be at the earlier stages. After driving around a bit on the motorway and in town while coming off a round about i gave the car throttle and suddenly boost just felt sluggish . After that I have noticed the boost now has been kicking in after 4000RPM.

I have checked the engine bay with the hoses and pipes and cant seem to find any thing that could have come off.

Just wondering if there are any suggestions before i take it back to the garage.

Cheers guys

[suprmanmr2]

hasnt any one had a similar problem before?

I did take it to the garage and still its causing difficulties in finding what the problem is.

Could it be the ebc by any chance and would there be any way of checking this?

All replies will be much appreciated

Thanks

[JAP BOY]

you could always try checking for error codes then reseting the ECU!!!

Also what revision are we on about here! REV1/2 Rectangular Rear lights or Rev3 with reverse lights in the centre panel!!!!!

[suprmanmr2]

thanks mate for the reply.

Its a rev2 turbo. Sorry for not mentioning that earlier on.

I have checked the ecu for error codes and nothing has come up. The light just keeps on blinking which indicates theres no problem detected?

Secondly i called up two of the garages and mentioned the problem.

First one said I may need to replace the coolant

The other garage told me I could of damaged my turbo?

Im really confused as to how to sort out this problem and my local mechanic who are pretty good reckon its the boost controller that is causing all this.

The boost and the car was running fine and after making a pit stop in tesco's i lowered my hi boost setting to 0.95 bar. My lo settings at 0.85. Before that the Hi mode was on 1 bar. After lowering it and driving the car around a corner the car didnt pick up on boost until i reached 4.5k rpm.

I have checked the pipes again just to make sure and diconnected the ebc unit but still the problem exists.

Could it be the boost solenoid by any chance? Would that have these sorts of side effects?

After 4.5k the boost kicks in fine and shoots off how its suppossed to but I cant even hear the turbo whine or spool before that.

Sorry guys for bombaring you with this long essay. Just wish I can have my tubby back to how it was and enjoy it.

Thanks for all help and feedback given.

[mrfil13]

could you not just turn off the boost controller and see what it runs like on actuator pressure only? If that runs fine then maybe ebc settings.

[suprmanmr2]

by tunring off the ebc you simply mean disconnecting the unit from the harness? I did that and it didnt make a difference. The car was the same. Didnt really make a difference.

Update: I have resetted the ecu by pulling out the 7.5 and 15 amp fuses for a while and then poping them back in. It still has not made a difference. Boost still comes on at 4.5k rpm.

The car feels terrible and i still cant understand or source the problem of this.

Thanks

[Tiny]

Id take it to 3S very good and decent prices and not far from you either.

[suprmanmr2]

yeah ive now booked my car in with 3S. Will take it there and find out the cause of the problem hopefully.

[MR2_RICH]

Check your decat pipe is not fouling on the wastegate.

Search on here for all sorts of problems associated with this. From what I have read it was all ok until you decated the car?

[suprmanmr2]

UPDATE: Since my previous post the following has been done. A new turbo has been put in. Which means the decat and pipes were all taken off. The bov was replaced with another one. The BC was disconnected and just to make sure we also replaced the induction kit temporarily.

However after putting in the other turbo the problem still existed. The car is still boosting at 4-4.5ish rpm and is hitting 0.7 bar boost in 2nd gear. I have plugged the BC back in now and set it to 0.9 bar.

After posting on other forums for help I once again decided to do the diagnostic and it showed 2 error codes. 24 and 31.

However I disconnected the battery and reseted the ecu. I took the car for a spin again and still nothing has changed. I did the diagnostic again this time not showing any errors.

So I havnt really got anywhere still.....

The only thing I can notice is the decat/turbo joint some flappy noise coming from there and not seeming smooth.

MR2_RICH thats what i thought and am thinking about the wastegate and decat but when i got it put on for the first time it was all working fine. The car just suddenly started to play up.

What do I do next....

By the way all the work was done by Luke @ Pacific work who has done a brill job but this car is really making it tricky finding the source.

[Leon.]

Hang on a minute!

You say the turbo was fine before the event, so how can you have suddenly developed a wastegate clearance issue?

After the event you say the turbo was boosting fine after 4.5k revs, so why on earth would you need to replace the turbo? If I've understood correctly, I hope an affiliate didn't suggest the turbo replacement, I'd be interested to hear why if they did!

I agree with an ebc issue, sounds like its not controlling the boost at all. Mine's doing the same at the moment as I have a problem with the boost sensor.

It could be the same with you, a bad electrical connection. If you get the real-time boost value up on screen, is it showing the boost continually changing?

It really helps to have a separate boost gauge so you can see if its working 100 percent correctly.

[jimGTS]

return the stock turbo actuator pipes, completely illiminate the ebc and all its components....

[suprmanmr2]

Hang on a minute!

You say the turbo was fine before the event, so how can you have suddenly developed a wastegate clearance issue?

After the event you say the turbo was boosting fine after 4.5k revs, so why on earth would you need to replace the turbo? If I've understood correctly, I hope an affiliate didn't suggest the turbo replacement, I'd be interested to hear why if they did!

I agree with an ebc issue, sounds like its not controlling the boost at all. Mine's doing the same at the moment as I have a problem with the boost sensor.

It could be the same with you, a bad electrical connection. If you get the real-time boost value up on screen, is it showing the boost continually changing?

It really helps to have a separate boost gauge so you can see if its working 100 percent correctly.

Basically firstly i got my car serviced from a local garage who put my new exhaust and decat on. The car ran fine throughout the whole day and suddenly just gave up and only boosted normally after 4-4.5k rpm.

After that I took it to Luke @ Pacific works where he did all the checks. The whole lot meaning dismantiling components etc and testing to see whether it made a difference or not. It just didnt at all.

After that he disconnected the wire of the ebc from the solenoid and still it remained the same.

He checked the play in the turbo and reckoned it was the turbo that needed replacing.

So off I went and bought another one and got that fitted on.

Took it for a test drive (ebc disconnected with the solenoid wire disconected) and the car still boosted after 4ish rpm and was hitting 0.7bar.

Result: Still the same as before. Boost kicks fine after 4k rpm.

I dont know what to do now. Ive tried searching the forums, posted everywhere, tried working out things but i just cant figure anything even with help.

Well now im going to disconnect the ebc completely like jimGTS has mentioned and see results and post up again.

Thanks guys for the comments/help.

Really appreciate it.

[Leon.]

Sounds to me like you're just running off stock boost control, esp if disconnecing the ebc wire made no difference. The extra length in your new hoses to the ebc would explain the extra lag compared to a completely stock setup.

Has either garage tried to set up your ebc again properly? When you changed the ebc value to 0.95, did the ebc go back into learn mode? Before I knew how to set it up it, mine acted exactly the same as yours has been doing. Its now reverted back to this as my boost sensor or wiring is playing up.

As I said, check the boost value is constantly changing not freezing first, and get it set up properly. If you don't know how to do either of these things just ask, I'd be happy to help.

Tbh, changing the turbo based on the above seems OTT but I don't have the car infront of me...

[suprmanmr2]

Sounds to me like you're just running off stock boost control, esp if disconnecing the ebc wire made no difference. The extra length in your new hoses to the ebc would explain the extra lag compared to a completely stock setup.

Has either garage tried to set up your ebc again properly? When you changed the ebc value to 0.95, did the ebc go back into learn mode? Before I knew how to set it up it, mine acted exactly the same as yours has been doing. Its now reverted back to this as my boost sensor or wiring is playing up.

As I said, check the boost value is constantly changing not freezing first, and get it set up properly. If you don't know how to do either of these things just ask, I'd be happy to help.

Tbh, changing the turbo based on the above seems OTT but I don't have the car infront of me...

When I first put the boost controller on it was working perfectly fine. I had it on for a month and after that when i got my car serviced from my local garage where he also put the exhaust and decat on the car ran perfect for 10 hours. I was pulling up in tesco and before turning the car off i actually lowered my boost to 0.95 from 1 bar. Did my shopping came back, filled in petrol, pulled out came to a roundabout and nailed it and noticed boost just didnt come on until late and it felt sluggy. I didnt hear any noises, nothing. Just suddenly.

I took it back to my local garage and he drove it about/checked it and reckoned it was the boost controller.

The condition of the boost controller seems fine. Its a used one i bought from ebay came from japan from that dino bloke on it. Its the older avcr the black quarter din one.

After that I took it to Luke @ Pacific works. He checked the boost controller and put it back in better shape with new pipes etc.

He replaced the BOV with another one. He used another induction kit including another AFM. It was still the same. He did the compression and the car came spot on. He checked the timing which was slight advance but said it would not make it slower but faster.

He then checked the turbo and span the shaft and there was play. When i bought the new one there were scratch marks around the shaft. SO wen put a new turbo in including the actuator and took it for a test without the boost controller running on actuator only.

The car sounded exactly like before horrible and boost kicked in at the same rev 4-4.5k rpm. Drove it back and more and more i drive it the more annoying it gets and sounds.

Ive now completely removed the boost controller and its still the same...

Any suggestions?

Thanks guys!

[Leon.]

My suggestion is still the same. you need to set the ebc up correctly.

The very fact it went boobs up after you changed the setting tells me this. Have the settings been checked yet? You probably have the gain too high if you just moved the boost down?

Try setting it to 1 bar again, set it in learn mode and see.

[jimGTS]

could always buy a cheap mbc to see how that behaves....

[Leon.]

Just to re-iterate, mine behaves exactly the same with the avc-r plumbed in but with the ebc not controling anything.

I bet a lot of money on it just needing to be set up right.

[Moo]

return the stock turbo actuator pipes, completely illiminate the ebc and all its components....

I had a similar problem recently and it turned out to be my EBC that was to blame. The electronic box that sits in the cabin was shot and even though it looked like it was working, was reading boost and displaying as normal etc it wasn't activating the solenoid. I was using a Greddy Profec B spec 2 as opposed to an AVCR but from what you've said it sounds very much like it might be your boost solenoid or the electronics box that's at fault.

I suggest the same as Jim. Return the actuator pipes to stock and bypass the EBC completely as this should tell you if the EBC is to blame.

Edit - Have just read what Leeroy has suggested and having had no personal experience with an AVCR it would be easier to try setting it up again before putting it back to stock. That would probably be the next step if you still get the same problems after setting up the AVCR again.

[suprmanmr2]

Hmmm

Well today I completely removed the avcr.

I returned the stock pipe going from the turbo to the actuator and removed the pressure pipe from the avcr sensor.

So now the solenoid is completely out of the car.

Only the unit was in but would that effect anything as only the wires are left connected to the ECU. or should i pull them out too.

However when i took the car for test drive it still seemed pretty much the same. On a few occasion the boost picked up at 3500ish rpm. But it was still heavy and sluggy. Could not feel the proper smooth torque that you get at low revs.

So all in all the ebc was completely out of the car and not functioning as i put the car back to original.

While taking off the solenoid and putting things back i removed the pipes from the turbo to the induction kit and checked them carefully but they all seem good.

My car definately doesnt seem right. I remember how nice is was to drive when it used to work properly. You could hear the turbo spool up at 2800-3000rpm and the gauge used to climb up nice and smoothly.

Well now its just dead at low rpms worse than driving a honda civic probably and the boost just comes on suddenly and pushes you back. Its just not right.

The main observation ive made is that i cant hear the turbo whine/spoon even while driving normally.

Only unless you floor it completely then only does the turbo kick in. Normal and general driving and the turbo is just completely dead.

So the ebc is out except for the wires coming from the ecu to the unit. Would that cause any disturbance if the unit is messed up?

Thanks guys!