boost sensor problem!

[Sig]

New poster! (less than 10 posts)

Hello people.
Been wanting a r5 for years and finally found one that I thought was a good one and I believe it is
when I brought it I know it needed a few common things doing to it fuel leak oil gauge just to name a few
I brought it as it was all standard apart from a better intercooler for reliably as this was what I was looking for standard.

So problem, when I had a run in this car and booted it just to see I found out the boost sensor is working lol turbo gauge is going to limit very quick under around 3000rpm engine losses power not cutting out then pop bang.

From reading I did not want to do this but ended up doing it just a few times removed the boost sensor booted the car on a few short run and works fine rpm can get higher and no engine shutdown.
Turbo has been messed with I was thinking?
So I went to change the turbo boost pressure on the actuator rod and bolt. I believe I went the correct way just a few turns anti clockwise this did not work it did not cut out as fast I think.... if I was to do it again there is not a lot of thread.

I am thinking of getting a psi gauge and a MANUAL BOOST CONTROLLER is this all I need to change the psi anything else? I would not keep this but just use to set it up so its at a safe level.
Ebay item numbers
360927189418 and 161166986347

anyone ever had this problem and what do you do? just run with the boost sensor removed all the time?
Any help from you guys would be great.
Thanks

[Matty]

To be honest I would put the boost back to standard, and leave it like that until you have a lambda sensor (wideband) fitted, otherwise it could not end well. if anything the over boost sensor could be saving any damage being done at present, unless it has been correctly set up?

The actuator will have a preload set on it from standard. When you remove it and the waste gate is fully shut, and you hold the actuator rod up against the lug it fits on, the arm is usually half a hole to a hole too short (if that makes sense?). Any more and it could cause more boost. With the boost set to factory setting, I think the needle should go to the '0' of 'turbo'on the OE gauge.

Check the vacuum/signal hoses from the carb to the actuator, and see if any bleed valves or restrictions have been fitted, and that they are in the correct place. There's a good thread on here with standard engine bay pics, to help determin they are plumbed correctly.

[Sig]

New poster! (less than 10 posts)

To be honest I would put the boost back to standard, and leave it like that until you have a lambda sensor (wideband) fitted, otherwise it could not end well. if anything the over boost sensor could be saving any damage being done at present, unless it has been correctly set up?

The actuator will have a preload set on it from standard. When you remove it and the waste gate is fully shut, and you hold the actuator rod up against the lug it fits on, the arm is usually half a hole to a hole too short (if that makes sense?). Any more and it could cause more boost. With the boost set to factory setting, I think the needle should go to the '0' of 'turbo'on the OE gauge.

Check the vacuum/signal hoses from the carb to the actuator, and see if any bleed valves or restrictions have been fitted, and that they are in the correct place. There's a good thread on here with standard engine bay pics, to help determin they are plumbed correctly.

Hello Matty
Thanks for your reply I do want to set the turbo back to standard or to a psi level that dose not make the boost sensor kick in. so if I brought this stuff I said on the 1st post from ebay.
this is all I need to get this turbo setup correct? I think I can find what the standard PSI is on here somewhere. I think the actuator has been drilled out to allow the last owner the change it manually so I don't really know where the preloaded set is any longer. I have turned it down and it seem to work with it taking longer for the boost sensor to kick in but its still to high and it only has one thread left to lower it down more.

what are these lambda sensor you said and what use would they be to me?
thanks for the help

[Trevhib]

Can you please take a picture of your engine bay and upload it here so we can see what's going on?

[Sig]

New poster! (less than 10 posts)

Can you please take a picture of your engine bay and upload it here so we can see what's going on?

hello,
yes I have taken some pictures if you need to see anything pacific just let me know and I will get it for you the last 2 pictures are something new I have just seen pipe from carb runs around to near the turbo but has a bolt in it.

Things I am unsure of pipe I just spoken about?
Actuator I know is been messed with. dose it look full open?
what is this in picture 4 missing a pipe or a filter from turbo?

Thanks

[Sig]

New poster! (less than 10 posts)

last 2 pictures from what I just seen pipe with a bolt in it running from carb?
thanks

[Matt_S]

That actuator is wound fully tight! Normally, you'd see some thread showing on the shaft, because it would be longer than yours.
Whee do the two smaller hoses go to/from? The kens tied to each other?

And the pipe you're missing looks to be the hot air feed to the air box from the heat turbo shield.

[Sig]

New poster! (less than 10 posts)

That actuator is wound fully tight! Normally, you'd see some thread showing on the shaft, because it would be longer than yours.
Whee do the two smaller hoses go to/from? The kens tied to each other?

And the pipe you're missing looks to be the hot air feed to the air box from the heat turbo shield.

so I need to undo the actuator more? I want to lower the boost so the boost sensor dose not come in and cut the car out.
The missing pipe is this needed to the hot air feed?
thanks for your time.

[Matt_S]

The boost sensor seems to be unplugged? That will need to go back In the system to stop over boosting. Unwinding the actuator will decrease the pressure on the spring in the diaphragm and reduce boost. You should also really un clip the arm from the waste gate and unwind rather than just undo it in situ.

Edit: I can see the wires on the sensor now.

And no, you don't really need the hot feed. It just helps warm the car up faster.

[Sig]

New poster! (less than 10 posts)

The boost sensor seems to be unplugged? That will need to go back In the system to stop over boosting. Unwinding the actuator will decrease the pressure on the spring in the diaphragm and reduce boost. You should also really un clip the arm from the waste gate and unwind rather than just undo it in situ.

Edit: I can see the wires on the sensor now.

And no, you don't really need the hot feed. It just helps warm the car up faster.

Thanks matt I will tomo unwind it to lower the boost I must of gone the wrong way as I was unsure.so too you it seems to be about on max? is there any way of finding out how far I should unwind it to standard psi with out a gauge length of rod? or is it trial and error? and use the turbo gauge?
thanks again for your time.

[Alex]

The actuator rod looks as rusty as hell, you'll have to WD40 it to get it moving. You don't need to unwind the whole rod, just the end with the hole in that goes onto the wastegate.

You can adjust the overboost sensor. There should be a small screw in the middle of it, screw it in to increase the boost before it will cut in.

[Shane P]

New poster! (less than 10 posts)is there any way of finding out how far I should unwind it to standard psi with out a gauge length of rod? or is it trial and error? and use the turbo gauge?
thanks again for your time.

I think this has already been described to you in post 2 of this thread, second paragraph :-)

[Trevhib]

Good advice.

Just to be clear then, the actuator 'rod-end' section needs to be unwound so that the rod length itself is lengthened overall. This will reduce the tension and require less boost to push the wastegate open


Which picture shows the carb pipe with the bolt in it?

[Sig]

New poster! (less than 10 posts)

Good advice.

Just to be clear then, the actuator 'rod-end' section needs to be unwound so that the rod length itself is lengthened overall. This will reduce the tension and require less boost to push the wastegate open


Which picture shows the carb pipe with the bolt in it?

Hello,
I will add it again for you
1st pic with the hand is where the pipe starts from the carb 2nd is where it ends with a bolt stuck up it.
with this actuator being rusty as hell you think I should just by a new one? seems to be working fine tho just set to high!

[Sig]

New poster! (less than 10 posts)

just want to thank you all with the info and help I will have a hour on it later tonight and let you know how I get on. I have big plans for this car needs a nice engine tidy up but the shell is in good condition as a base to start insides good too. it sounds sweet starts first time no smoke at all so hopefully I got a good one.

[Shane P]

New poster! (less than 10 posts)



Hello,
I will add it again for you
1st pic with the hand is where the pipe starts from the carb 2nd is where it ends with a bolt stuck up it.

That pipe is the carb overflow pipe, a safety precaution in case of a faulty carb. Fuel is directed down this pipe if the carb internals fail. The pipe needs to be unblocked and directed down somewhere between the front of the engine and the radiator fan, or basically anywhere away from the hot turbo and exhaust.

[Trevhib]

Yep

[Sig]

New poster! (less than 10 posts)

Yep all sorted now boost was set stupid high no idea what the old owner was doing again thanks for all the help

[Matty]

Glad you got it sorted...nice easy fix in the end then.

[Sig]

Hi all,
So thought I would follow this from this post as I think it's related???
Went on a bit of a longer drive today. On the motorway and gets up to 50mph with ease. Any more this boost sensor is going to kick in again. 5th gear still wants to pull but hitting redline on boost gauge. Is it still set to high..? The only way I can get it to go past 50mph is let go of Accelerator for a sec boost gauge goes down then go again it goes up in about 15mph stages.
This surly is not correct..?
Thanks

[Sig]

I am sure there is not a lot on the waste gate to lower the boost down more. Can I just run it without this boost sensor as I see many not doing so..? I do have a uprated intercooler??
Thanks

[Trevhib]

The over boost sensor shouldn't be cutting in at the first red line on the boost gauge. As standard I think the sensor is set to come in about 15psi, which is further into the hashed red section on your standard gauge (approximately half way into the red section).

IF the over boost sensor is cutting in too early on your gauge, it could suggest that you have a boost leak, somewhere between the sensor itself and the carb top where the gauge feed and actuator piping is.

Potential scenario: some boost is being leaked away, say from the main boost hose, so the gauge shows less pressure than the turbo actually is pushing out. More importantly, the boost leak means that the actuator pipes don't receive enough of the turbo pressure to open the wastegate. However, the boost sensor, being close to the turbo, is seeing enough of the pressure to cut the ignition, thus saving the turbo from being damaged.

The first question is, exactly where on your boost gauge is the car cutting out. Secondly, check the whole system for leaks. Sometimes leaks don't show up until the system is pressurised. Thirdly, is your over boost sensor one of the adjustable types (i.e. does it have a little screw in the top of it).

My advice would also be to get an after market boost gauge and simply plumb it in to the AEI line to check what pressure the engine is seeing at all times. If it's below 15psi maximum, you know your problem is more likely a boost leak (and damaging the turbo more and less so the engine).

Yes you can just disconnect the over boost sensor. However, if it is a boost leak, your turbo will be at risk and the boost temps will be higher than they should be.

Your intercooler appears to be an aluminium one, i.e. non-standard.

[Trevhib]

Just looking again at your actuator piping. Something has been plumbed into the line that runs from the carb top to the actuator port nearest the radiator. It's been extended significantly. What the heck is that?

[RussellT]

I agree with Trevor something has been plumbed into the pipes to the wastegate actuator. Follow them to the left side of the car and I susspect you will find a bleed valve. One thing is clear this is not a standard car and is likely to have been abused.

[Sig]

I agree with Trevor something has been plumbed into the pipes to the wastegate actuator. Follow them to the left side of the car and I susspect you will find a bleed valve. One thing is clear this is not a standard car and is likely to have been abused.

Hello thanks for the help I am away atm but when I get back in 5 days I am going to do as you say and have a look. Could u point out in what picture and what pipe looks like it should not be there the 2 small ones of the wastegate.? Or the one off the boost big pipe..?
If anyone can link me to the correct stuff I would need to add a boost psi censor that would be great to there are just so many and different connections.
Thanks again!!

[Trevhib]

I've done a screencast to describe exactly what I'm talking about:
http://screencast-o-matic.com/watch/c2XI6TeDPe

[Trevhib]

And you can see in this thread what standard engine bay piping should look like (down in the second half of the first page):
https://www.rtoc.org/boards/showthread.php?t=38043

[Matty]

That looks like its a bleed valve plumbed in, they look like the classic blue silicon vacuum hoses you get with them.

[RussellT]

That "screencast" is slick Trevor

[Trevhib]

Thanks Russell

The screencast-o-matic website is awesome. So simple (and free), and quick to use. You don't get any editing capabilities but if you can do what you need in one take, it's great for recording your PC/laptop screen (and audio over it). After you're finished, it's one click to either delete, upload the video to their site, or upload to Youtube.

http://www.screencast-o-matic.com/

I don't know why I haven't used it for RTOC stuff before tbh.

[Sig]

Thanks Russell

The screencast-o-matic website is awesome. So simple (and free), and quick to use. You don't get any editing capabilities but if you can do what you need in one take, it's great for recording your PC/laptop screen (and audio over it). After you're finished, it's one click to either delete, upload the video to their site, or upload to Youtube.

http://www.screencast-o-matic.com/

I don't know why I haven't used it for RTOC stuff before tbh.

Hey all,
So just got back in the uk first thing I did look as this pipe! You people know everything!!!
so I have took The pipe back to how you said and all works fine boost gauge dose not redline now no matter how hard you push in any gear. so I can go past 50mph in 5th without having let the boost out before going again and no redline.
I have added pictures of what I found in the car and the pipes my question is what is missing so I could use this boost Manual Adjustable Boost Controller if it is one?
Also 3 pipes from it only 2 connected to other pipes? other just resting in engine bay open ended.
Thanks For all the help and that video!!!

[Trevhib]

Holy moly, that's a bleed valve without the screw top, it's been screwed out so far it's come out! Meaning you're bleeding as much pressure as possible. No wonder you couldn't set a decent limit.

Do you have that part somewhere? If so, you simply need to screw it back in and then you can use it to control the boost level, to a degree.

It should look a bit like this:

[Trevhib]

Also, you asked a question about one of the pipes being unattached. That's correct, it vents the air/fumes away from the cabin. Otherwise it would stink your car out.

The actual plumbing on the valve itself seems ok. You either need to find the screw top (or get a second hand one) and refit it, or ditch the whole thing and drive the car as you have it now.

[Sig]

Also, you asked a question about one of the pipes being unattached. That's correct, it vents the air/fumes away from the cabin. Otherwise it would stink your car out.

The actual plumbing on the valve itself seems ok. You either need to find the screw top (or get a second hand one) and refit it, or ditch the whole thing and drive the car as you have it now.

Hello, no I don't Have the screw in part lol
I will leave it like this and then maybe buy this?

http://www.ebay.co.uk/itm/In-Car-Boo...item3398a7a81d

Do they have to have 3 pipe outlets as some have 2?
finally I want to add a Psi gauge to see what the hell its been set to Can I use this pipework that's been plumbed in already or do they work in a different way?
Thanks again!

[Trevhib]

Bleed valves:

A bleed valve with two outlets means you plumb it in under the bonnet, so that escaping gasses don't asphyxiate you, lol. You don't want one of these.

Yes, if you buy that 3-port bleed valve on ebay you can just remove the one that's on your car and install the new one using the same pipes.



Boost gauge:

As for fitting a PSI boost gauge, as mentioned in my previous post. Buy one and 'T-in' to the pipe that runs from the side of the carb to the AEI unit (that is the black box that has the ignition unit in it that sits underneath the plastic scuttle cover).

http://www.ebay.co.uk/itm/Electrical...item19f57de392

[Sig]

Bleed valves:

A bleed valve with two outlets means you plumb it in under the bonnet, so that escaping gasses don't asphyxiate you, lol. You don't want one of these.

Yes, if you buy that 3-port bleed valve on ebay you can just remove the one that's on your car and install the new one using the same pipes.



Boost gauge:

As for fitting a PSI boost gauge, as mentioned in my previous post. Buy one and 'T-in' to the pipe that runs from the side of the carb to the AEI unit (that is the black box that has the ignition unit in it that sits underneath the plastic scuttle cover).

http://www.ebay.co.uk/itm/Electrical...item19f57de392

Hello
Ok so got the manual boost control today the screw that was missing out of mine fitted from the new one so I just done a quick fix fitted the internal boost pipes back how they was on the turbo put the boost control screw in and all the way down had a spin boosts faster but now only hitting just over half way on turbo gauge, before when I had it set to standard pipe to sort out my over boost problem it would go about half way.So I open the manual boost valve just half a turn and its to much hitting that boost sensor and cutting out.Also 1st gear seems sluggish to 2nd for turbo this ok?
So I thought this would allow me to set up a safe boost and get a bit more out of it than standard settings.Do I still need to play with the actuator rod to set it up even if I am using a boost control? I was thinking the actuator rod is shorted a lot but from taking away the manual boost control pipe it can not be as its only boosting about half half way on the gauge.???
I no I need a psi gauge its on its way just for now was going to use the turbo gauge and the over boost sensor to set it up hoping the actuator rod was open full nearly and I could change the boost from manual boost control inside my car
Thanks!!

[RussellT]

Sig
close the bleed valve and take it to someone who knows what they are doing before you blow your engine up!
Russell

[Sig]

Sig
close the bleed valve and take it to someone who knows what they are doing before you blow your engine up!
Russell

you might be right but you never learn that way I think I will put it back until I get this psi gauge. just so you understand I don't really want this but as the manual boost control was all ready there with out the screw cap and the turbo actuator rod has been shorted we believed massively I have no mark to set it to standard I thought this would be the best way to find standard and up it just abit to a safe 10/11psi from my reading this is safe with the setup I have and 14psi would be the max.
So is there any actuator rod info on the length is should be set to standard? or can it only be done with a psi boost gauge and back and forth changing the rod length if I could get that to the right setting I would not even use the boost control I just brought.
Thanks again

[Shane P]

1. Your actuator rod needs to be lengthened to the point that is between 'half a hole' to 'a hole' away from the wastegate lever pin to set the preload near standard, on a standard actuator on a standard T2 turbocharger.

2. Manual boost controllers are horrendous :-) , and the entire setup and it's piping needs to go in the bin before the engine does.

3. The actuator to carb pipework needs to be put back to standard if it isn't already.

4. Be thankful for the overboost kicking in, it's currently saving your engine :-).

5. A correctly plummed in Boost and AFR gauge needs to be installed before the boost is touched again.

6. Standard boost a phase 2 is around 10psi. Unless you have the above fitted you maximum is 10psi !


Good luck

[Trevhib]

Hello
Ok so got the manual boost control today the screw that was missing out of mine fitted from the new one so I just done a quick fix fitted the internal boost pipes back how they was on the turbo put the boost control screw in and all the way down had a spin boosts faster but now only hitting just over half way on turbo gauge, before when I had it set to standard pipe to sort out my over boost problem it would go about half way.

That sounds correct. It was going to halfway when the piping was standard, and is going to halfway with the boost controller plumbed in and the screw all the way in (i.e. not venting any boost). It should be the same and is the same, all good then no?

So I open the manual boost valve just half a turn and its to much hitting that boost sensor and cutting out.

In my experience, half a turn can mean a significant increase, depending on the type of bleed valve it is. Where are you getting to on the gauge before the over-boost is kicking in? What about a quarter of a turn?

Also 1st gear seems sluggish to 2nd for turbo this ok?

When is this happening? Without the boost controller, only with the boost controller when the screw is full in, only with the boost controller but when the screw is unwound a bit, at all times with the boost controller fitted, or all the time?

So I thought this would allow me to set up a safe boost and get a bit more out of it than standard settings.

It should, you just have a problem somewhere.

Do I still need to play with the actuator rod to set it up even if I am using a boost control?

Not if the rod was set to the standard length (but we know it's not). The situation should be that: the actuator has a standard rod length, you fit a bleed valve and then open it a fraction to increase the boost a little.

I was thinking the actuator rod is shorted a lot but from taking away the manual boost control pipe it can not be as its only boosting about half half way on the gauge.???

Then perhaps some of these issues (including the sluggishness), point to a potential boost leak still.

I no I need a psi gauge its on its way, just for now I was going to use the turbo gauge and the over boost sensor to set it up hoping the actuator rod was open full nearly and I could change the boost from manual boost control inside my car
Thanks!!

Yep, in theory you should be able to do as you have described but it looks like you have other issues that are causing your problems. In the meantime then you should put the piping back to standard, set the actuator rod as Shane describes and test the car to see that it runs ok. Then once your new boost gauge arrives, plumb it into the AEI line from the carb and see what it says and report back